Abstract

The growth of single and multiple (three) ZnO/ZnMgO quantum well samples on sapphire substrates, through a two-step temperature variation growth of ZnO buffer layers by molecular beam epitaxy (MBE), were investigated. For single quantum well (QW) growth, the thicker first ZnMgO barrier layer about 220 nm on the high-temperature growth ZnO (HT-ZnO) buffer layer, accumulated larger compressive stress, to achieve higher quality ZnO/ZnMgO QW growth. In the temperature-dependent photoluminescence (PL) results, the obvious S-shape variation of emission peak positions presented the stronger exciton confinement ability of QW in the higher magnesium concentrations of ZnMgO barrier layer growth. Compared to the control sample, the quantum confinement resulted in blueshift PL peaks of QW samples at low temperature. The multiple quantum well (MQWs) structure increased the exciton confinement ability to enhance the light emission efficiency of the sample. The three ZnO/ZnMgO MQWs structures were found clearly by high-resolution transmission electron microscopy.

© 2013 OSA

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2012 (5)

R. Thierry, G. Perillat-Merceroz, P. H. Jouneau, P. Ferret, and G. Feuillet, “Core-shell multi-quantum wells in ZnO/ZnMgO nanowires with high optical efficiency at room temperature,” Nanotechnology23(8), 085705 (2012).
[CrossRef] [PubMed]

E. Francesco Pecora, W. Zhang, A. Yu. Nikiforov, L. Zhou, D. J. Smith, J. Yin, R. Paiella, L. Dal Negro, and T. D. Moustakas, “Sub-250 nm room-temperature optical gain from AlGaN/AlN multiple quantum wells with strong band-structure potential fluctuations,” Appl. Phys. Lett.100(6), 061111 (2012).
[CrossRef]

G. Liu, J. Zhang, X. H. Li, G. S. Huang, T. Paskova, K. R. Evans, H. Zhao, and N. Tansu, “Metalorganic vapor phase epitaxy and characterizations of nearly-lattice-matched AlInN alloys on GaN/sapphire templates and free-standing GaN substrates,” J. Cryst. Growth340(1), 66–73 (2012).
[CrossRef]

S. Y. Ting, P. J. Chen, H. C. Wang, C. H. Liao, W. M. Chang, Y. P. Hsieh, and C. C. Yang, “Crystallinity improvement of ZnO thin film on different buffer layers grown by MBE,” J. Nanomater.2012, 6 (2012), doi:.
[CrossRef]

K. Wu, H. He, Y. Lu, J. Huang, and Z. Ye, “Dominant free exciton emission in ZnO nanorods,” Nanoscale4(5), 1701–1706 (2012).
[CrossRef] [PubMed]

2011 (6)

H. P. Zhao, G. Y. Liu, J. Zhang, J. D. Poplawsky, V. Dierolf, and N. Tansu, “Approaches for high internal quantum efficiency green InGaN light-emitting diodes with large overlap quantum wells,” Opt. Express19(S4Suppl 4), A991–A1007 (2011).
[CrossRef] [PubMed]

R. B. Chung, F. Wu, R. Shivaraman, S. Keller, S. P. DenBaars, J. S. Speck, and S. Nakamura, “Growth study and ipurity characterization of AlxIn1−xN grown by metal organic chemical vapor deposition,” J. Cryst. Growth324(1), 163–167 (2011).
[CrossRef]

J. Zhang, H. Zhao, and N. Tansu, “Large optical gain AlGaN-delta-GaN quantum wells laser active regions in mid- and deep-ultraviolet spectral regimes,” Appl. Phys. Lett.98(17), 171111 (2011).
[CrossRef]

Y. Taniyasu and M. Kasu, “Polarization property of deep-ultraviolet light emission from C-plane AlN/GaN short-period superlattices,” Appl. Phys. Lett.99(25), 251112 (2011).
[CrossRef]

M. Brandt, H. Wenckstern, M. Stölzel, H. Hochmuth, M. Lorenz, and M. Grundmann, “Semiconducting oxide heterostructures,” Semicond. Sci. Technol.26(1), 014040 (2011).
[CrossRef]

H. Long, G. Fang, S. Li, X. Mo, H. Wang, H. Huang, Q. Jiang, J. Wang, and X. Zhao, “A ZnO/ZnMgO multiple-quantum-well ultraviolet random laser diode,” IEEE Electron Device Lett.32(1), 54–56 (2011).
[CrossRef]

2010 (5)

C. R. Hall, L. V. Dao, K. Koike, S. Sasa, H. H. Tan, M. Inoue, M. Yano, C. Jagadish, and J. A. Davis, “Using graded barriers to control the optical properties of ZnO/Zn0.7Mg0.3O quantum wells with an intrinsic internal electric field,” Appl. Phys. Lett.96(19), 193117 (2010).
[CrossRef]

M. Brandt, M. Lange, M. Stölzel, A. Müller, G. Benndorf, J. Zippel, J. Lenzner, M. Lorenz, and M. Grundmann, “Control of interface abruptness of polar MgZnO/ZnO quantum wells grown by pulsed laser deposition,” Appl. Phys. Lett.97(5), 052101 (2010).
[CrossRef]

J. Zhang, H. Zhao, and N. Tansu, “Effect of crystal-field split-off hole and heavy-hole bands crossover on gain characteristics of high Al-content AlGaN quantum well lasers,” Appl. Phys. Lett.97(11), 111105 (2010).
[CrossRef]

J. G. Kim, S. K. Han, S. M. Yang, S. K. Hong, J. W. Lee, J. Y. Lee, J. H. Song, Y. E. Ihm, D. Kim, J. S. Park, H. J. Lee, and T. Yao, “Effects of low temperature ZnO and MgO buffer thicknesses on properties of ZnO films grown on (0001) Al2O3 substrates by plasma-assisted molecular beam epitaxy,” Thin Solid Films519(1), 223–227 (2010).
[CrossRef]

Y. J. Chen, Y. Y. Shih, C. H. Ho, J. H. Du, and Y. P. Fu, “Effect of temperature on lateral growth of ZnO grains grown by MOCVD,” Ceram. Int.36(1), 69–73 (2010).
[CrossRef]

2009 (1)

H. P. Zhao, G. Y. Liu, X. H. Li, R. A. Arif, G. S. Huang, J. D. Poplawsky, S. Tafon Penn, V. Dierolf, and N. Tansu, “Design and characteristics of staggered InGaN quantum well light-emitting diodes in the green spectral regimes,” IET Optoelectron.3(6), 283–295 (2009).
[CrossRef]

2008 (1)

S. Y. O, C.-G. Lee, A. J. Shapiro, W. F. Egelhoff, M. D. Vaudin, J. L. Ruglovsky, J. Mallett, and P. W. T. Pong, “X-ray diffraction study of the optimization of MgO growth conditions for magnetic tunnel junctions,” J. Appl. Phys.103(7), 07A920 (2008).
[CrossRef]

2007 (5)

A. Bakin, J. Kioseoglou, B. Pecz, A. El-Shaer, A.-C. Mofor, J. Stoemenos, and A. Waag, “Misfit reduction by a spinel layer formed during the epitaxial growth of ZnO on sapphire using a MgO buffer layer,” J. Cryst. Growth308(2), 314–320 (2007).
[CrossRef]

R. A. Arif, Y.-K. Ee, and N. Tansu, “Polarization engineering via staggered InGaN quantum wells for radiative efficiency enhancement of light emitting diodes,” Appl. Phys. Lett.91(9), 091110 (2007).
[CrossRef]

X. Q. Gu, L. P. Zhu, Z. Z. Ye, H. P. He, Y. Z. Zhang, F. Huang, M. X. Qiu, Y. J. Zeng, F. Liu, and W. Jaeger, “Room-temperature photoluminescence from ZnO/ZnMgO multiple quantum wells grown on Si(111) substrates,” Appl. Phys. Lett.91(2), 022103 (2007).
[CrossRef]

A. Bakin, J. Kioseoglou, B. Pecz, A. El-Shaer, A.-C. Mofor, J. Stoemenos, and A. Waag, “Misfit reduction by a spinel layer formed during the epitaxial growth of ZnO on sapphire using a MgO buffer layer,” J. Cryst. Growth308(2), 314–320 (2007).
[CrossRef]

A. El-Shaer, A. Bakin, M. Al-Suleiman, S. Ivanov, A. Che Mofor, and A. Waag, “Growth of wide band gap wurtzite ZnMgO layers on (0001) Al2O3 by radical-source molecular beam epitaxy,” Superlattices Microstruct.42(1-6), 129–133 (2007).
[CrossRef]

2006 (5)

H. Matsui, H. Tabata, N. Hasuike, and H. Harima, “Critical thickness and lattice relaxation of Mg-rich strained Mg0.37Zn0.63O (0001) layers towards multi-quantum-wells,” J. Appl. Phys.99(2), 024902 (2006).
[CrossRef]

K. Koike, G. Y. Takada, K. Fujimoto, S. Sasa, M. Inoue, and M. Yano, “Characterization of [ZnO]m[ZnMgO]n multiple quantum wells grown by molecular beam epitaxy,” Physica E32(1-2), 191–194 (2006).
[CrossRef]

V. A. Coleman, M. Buda, H. H. Tan, C. Jagadish, M. R. Phillips, K. Koike, S. Sasa, M. Inoue, and M. Yano, “Observation of blue shifts in ZnO/ZnMgO multiple quantum well structures by ion-implantation induced intermixing,” Semicond. Sci. Technol.21(3), L25–L28 (2006).
[CrossRef]

J. H. Lim, C. K. Kang, K. K. Kim, I. K. Park, D. K. Hwang, and S. J. Park, “UV electroluminescence emission from ZnO light-emitting diodes grown by high-temperature radiofrequency sputtering,” Adv. Mater. 18(20), 2720–2724 (2006).
[CrossRef]

H. Matsui, H. Tabata, N. Hasuike, and H. Harima, “Critical thickness and lattice relaxation of Mg-rich strained Mg0.37Zn0.63O (0001) layers towards multi-quantum-wells,” J. Appl. Phys.99(2), 024902 (2006).
[CrossRef]

2005 (4)

Y. Chen, F. Jiang, L. Wang, C. Zheng, J. Dai, Y. Pu, and W. Fang, “Structural and luminescent properties of ZnO epitaxial film grown on Si(111) substrate by atmospheric-pressure MOCVD,” J. Cryst. Growth275(3-4), 486–491 (2005).
[CrossRef]

T. Makino, Y. Segawa, M. Kawasaki, and H. Koinuma, “Optical properties of excitons in ZnO-based quantum well heterostructures,” Semicond. Sci. Technol.20(4), S78–S91 (2005).
[CrossRef]

T. Makino, Y. Segawa, and M. Kawasaki, “Analytical study on exciton - longitudinal - optical - phonon coupling and comparison with experiment for ZnO quantum wells,” J. Appl. Phys.97(10), 106111 (2005).
[CrossRef]

K. Koike, I. Nakashima, K. Hashimoto, S. Sasa, M. Inoue, and M. Yano, “Characteristics of a Zn0.7Mg0.3O/ZnO heterostructure field-effect transistor grown on sapphire substrate by molecular-beam epitaxy,” Appl. Phys. Lett.87(11), 112106 (2005).
[CrossRef]

2004 (2)

T. Gruber, C. Kirchner, R. Kling, F. Reuss, and A. Waag, “ZnMgO epilayers and ZnO-ZnMgO quantum wells for optoelectronic applications in the blue and UV spectral region,” Appl. Phys. Lett.84(26), 5359–5361 (2004).
[CrossRef]

H. Kato, K. Miyamoto, M. Sano, and T. Yao, “Polarity control of ZnO on sapphire by varying the MgO buffer layer thickness,” Appl. Phys. Lett.84(22), 4562–4564 (2004).
[CrossRef]

2003 (1)

T. Gruber, C. Kirchner, R. Kling, F. Reuss, A. Waag, F. Bertram, D. Forster, J. Christen, and M. Schreck, “Optical and structural analysis of ZnCdO layers grown by metalorganic vapor-phase epitaxy,” Appl. Phys. Lett.83(16), 3290–3292 (2003).
[CrossRef]

2002 (3)

T. Makino, K. Tamura, C. H. Chia, Y. Segawa, M. Kawasaki, A. Ohtomo, and H. Koinuma, “Effect of MgZnO-layer capping on optical properties of ZnO epitaxial layers,” Appl. Phys. Lett.81(12), 2172–2174 (2002).
[CrossRef]

D. Sun, Y. Segawa, M. Kawasaki, A. Ohtomo, K. Tamura, and H. Koinuma, “Phonon replicas in ZnO/ZnMgO multiquantum wells,” J. Appl. Phys.91(10), 6457–6460 (2002).
[CrossRef]

S. Pereira, M. R. Correia, E. Pereira, C. Trager-Cowan, F. Sweeney, K. P. O’Donnell, E. Alves, N. Franco, and A. D. Sequeira, “Structural and optical properties of InGaN/GaN layers close to the critical layer thickness,” Appl. Phys. Lett.81(7), 1207–1209 (2002).
[CrossRef]

2001 (6)

T. Makino, N. T. Tuan, H. D. Sun, C. H. Chia, Y. Segawa, M. Kawasaki, A. Ohtomo, K. Tamura, T. Suemoto, H. Akiyama, M. Baba, S. Saito, T. Tomita, and H. Koinuma, “Temperature dependence of near ultraviolet photoluminescence in ZnO/(Mg,Zn)O multiple quantum wells,” Appl. Phys. Lett.78(14), 1979–1981 (2001).
[CrossRef]

Y. Chen, S. K. Hong, H. J. Ko, V. Kirshner, H. Wenisch, T. Yao, K. Inaba, and Y. Segawa, “Effects of an extremely thin buffer on heteroepitaxy with large lattice mismatch,” Appl. Phys. Lett.78(21), 3352–3354 (2001).
[CrossRef]

D. C. Look, “Recent advances in ZnO materials and devices,” Mater. Sci. Eng. B80(1-3), 383–387 (2001).
[CrossRef]

G. Coli and K. K. Bajaj, “Excitonic transitions in ZnO/MgZnO quantum well heterostructures,” Appl. Phys. Lett.78(19), 2861–2863 (2001).
[CrossRef]

T. Makino, Y. Segawa, M. Kawasaki, A. Ohtomo, R. Shiroki, K. Tamura, T. Yasuda, and H. Koinuma, “Band gap engineering based on MgxZn1−xO and CdyZn1−yO ternary alloy films,” Appl. Phys. Lett.78(9), 1237–1239 (2001).
[CrossRef]

W. I. Park, G. C. Yi, and H. M. Jang, “Metalorganic vapor-phase epitaxial growth and photoluminescent properties of Zn1−xMgxO(0 ≤ x ≤ 0.49) thin films,” Appl. Phys. Lett.79(13), 2022–2024 (2001).
[CrossRef]

2000 (2)

T. Makino, C. H. Chia, N. T. Tuan, H. D. Sun, Y. Segawa, M. Kawasaki, A. Ohtomo, K. Tamura, and H. Koinuma, “Room-temperature luminescence of excitons in ZnO/(Mg,Zn) O multiple quantum wells on lattice-matched substrates,” Appl. Phys. Lett.77(7), 975–977 (2000).
[CrossRef]

Y. Chen, H. J. Ko, S. K. Hong, and T. Yao, “Layer-by-layer growth of ZnO epilayer on Al2O3 (0001) by using a MgO buffer layer,” Appl. Phys. Lett.76(5), 559–561 (2000).
[CrossRef]

1998 (2)

T. Sugahara, M. Hao, T. Wang, D. Nakagawa, Y. Naoi, K. Nishino, and S. Sakai, “Role of dislocation in InGaN phase separation,” Jpn. J. Appl. Phys. Part 237(Part 2, No. 10B), L1195–L1198 (1998).
[CrossRef]

A. Ohtomo, M. Kawasaki, T. Koida, K. Masubuchi, H. Koinuma, Y. Sakurai, Y. Yoshida, T. Yasuda, and Y. Segawa, “MgxZn1−xO as a II–VI widegap semiconductor alloy,” Appl. Phys. Lett.72(19), 2466–2468 (1998).
[CrossRef]

1997 (2)

M. Shimizu, Y. Kawaguchi, K. Hiramatsu, and N. Sawaki, “Metalorganic vapor phase epitaxy of thick InGaN on sapphire substrate,” Jpn. J. Appl. Phys. Part 136(Part 1, No. 6A), 3381–3384 (1997).
[CrossRef]

D. M. Bagnall, Y. F. Chen, Z. Zhu, T. Yao, S. Koyama, M. Y. Shen, and T. Goto, “Optically pumped lasing of ZnO at room temperature,” Appl. Phys. Lett.70(17), 2230–2232 (1997).
[CrossRef]

Akiyama, H.

T. Makino, N. T. Tuan, H. D. Sun, C. H. Chia, Y. Segawa, M. Kawasaki, A. Ohtomo, K. Tamura, T. Suemoto, H. Akiyama, M. Baba, S. Saito, T. Tomita, and H. Koinuma, “Temperature dependence of near ultraviolet photoluminescence in ZnO/(Mg,Zn)O multiple quantum wells,” Appl. Phys. Lett.78(14), 1979–1981 (2001).
[CrossRef]

Al-Suleiman, M.

A. El-Shaer, A. Bakin, M. Al-Suleiman, S. Ivanov, A. Che Mofor, and A. Waag, “Growth of wide band gap wurtzite ZnMgO layers on (0001) Al2O3 by radical-source molecular beam epitaxy,” Superlattices Microstruct.42(1-6), 129–133 (2007).
[CrossRef]

Alves, E.

S. Pereira, M. R. Correia, E. Pereira, C. Trager-Cowan, F. Sweeney, K. P. O’Donnell, E. Alves, N. Franco, and A. D. Sequeira, “Structural and optical properties of InGaN/GaN layers close to the critical layer thickness,” Appl. Phys. Lett.81(7), 1207–1209 (2002).
[CrossRef]

Arif, R. A.

H. P. Zhao, G. Y. Liu, X. H. Li, R. A. Arif, G. S. Huang, J. D. Poplawsky, S. Tafon Penn, V. Dierolf, and N. Tansu, “Design and characteristics of staggered InGaN quantum well light-emitting diodes in the green spectral regimes,” IET Optoelectron.3(6), 283–295 (2009).
[CrossRef]

R. A. Arif, Y.-K. Ee, and N. Tansu, “Polarization engineering via staggered InGaN quantum wells for radiative efficiency enhancement of light emitting diodes,” Appl. Phys. Lett.91(9), 091110 (2007).
[CrossRef]

Baba, M.

T. Makino, N. T. Tuan, H. D. Sun, C. H. Chia, Y. Segawa, M. Kawasaki, A. Ohtomo, K. Tamura, T. Suemoto, H. Akiyama, M. Baba, S. Saito, T. Tomita, and H. Koinuma, “Temperature dependence of near ultraviolet photoluminescence in ZnO/(Mg,Zn)O multiple quantum wells,” Appl. Phys. Lett.78(14), 1979–1981 (2001).
[CrossRef]

Bagnall, D. M.

D. M. Bagnall, Y. F. Chen, Z. Zhu, T. Yao, S. Koyama, M. Y. Shen, and T. Goto, “Optically pumped lasing of ZnO at room temperature,” Appl. Phys. Lett.70(17), 2230–2232 (1997).
[CrossRef]

Bajaj, K. K.

G. Coli and K. K. Bajaj, “Excitonic transitions in ZnO/MgZnO quantum well heterostructures,” Appl. Phys. Lett.78(19), 2861–2863 (2001).
[CrossRef]

Bakin, A.

A. Bakin, J. Kioseoglou, B. Pecz, A. El-Shaer, A.-C. Mofor, J. Stoemenos, and A. Waag, “Misfit reduction by a spinel layer formed during the epitaxial growth of ZnO on sapphire using a MgO buffer layer,” J. Cryst. Growth308(2), 314–320 (2007).
[CrossRef]

A. El-Shaer, A. Bakin, M. Al-Suleiman, S. Ivanov, A. Che Mofor, and A. Waag, “Growth of wide band gap wurtzite ZnMgO layers on (0001) Al2O3 by radical-source molecular beam epitaxy,” Superlattices Microstruct.42(1-6), 129–133 (2007).
[CrossRef]

A. Bakin, J. Kioseoglou, B. Pecz, A. El-Shaer, A.-C. Mofor, J. Stoemenos, and A. Waag, “Misfit reduction by a spinel layer formed during the epitaxial growth of ZnO on sapphire using a MgO buffer layer,” J. Cryst. Growth308(2), 314–320 (2007).
[CrossRef]

Benndorf, G.

M. Brandt, M. Lange, M. Stölzel, A. Müller, G. Benndorf, J. Zippel, J. Lenzner, M. Lorenz, and M. Grundmann, “Control of interface abruptness of polar MgZnO/ZnO quantum wells grown by pulsed laser deposition,” Appl. Phys. Lett.97(5), 052101 (2010).
[CrossRef]

Bertram, F.

T. Gruber, C. Kirchner, R. Kling, F. Reuss, A. Waag, F. Bertram, D. Forster, J. Christen, and M. Schreck, “Optical and structural analysis of ZnCdO layers grown by metalorganic vapor-phase epitaxy,” Appl. Phys. Lett.83(16), 3290–3292 (2003).
[CrossRef]

Brandt, M.

M. Brandt, H. Wenckstern, M. Stölzel, H. Hochmuth, M. Lorenz, and M. Grundmann, “Semiconducting oxide heterostructures,” Semicond. Sci. Technol.26(1), 014040 (2011).
[CrossRef]

M. Brandt, M. Lange, M. Stölzel, A. Müller, G. Benndorf, J. Zippel, J. Lenzner, M. Lorenz, and M. Grundmann, “Control of interface abruptness of polar MgZnO/ZnO quantum wells grown by pulsed laser deposition,” Appl. Phys. Lett.97(5), 052101 (2010).
[CrossRef]

Buda, M.

V. A. Coleman, M. Buda, H. H. Tan, C. Jagadish, M. R. Phillips, K. Koike, S. Sasa, M. Inoue, and M. Yano, “Observation of blue shifts in ZnO/ZnMgO multiple quantum well structures by ion-implantation induced intermixing,” Semicond. Sci. Technol.21(3), L25–L28 (2006).
[CrossRef]

Chang, W. M.

S. Y. Ting, P. J. Chen, H. C. Wang, C. H. Liao, W. M. Chang, Y. P. Hsieh, and C. C. Yang, “Crystallinity improvement of ZnO thin film on different buffer layers grown by MBE,” J. Nanomater.2012, 6 (2012), doi:.
[CrossRef]

Che Mofor, A.

A. El-Shaer, A. Bakin, M. Al-Suleiman, S. Ivanov, A. Che Mofor, and A. Waag, “Growth of wide band gap wurtzite ZnMgO layers on (0001) Al2O3 by radical-source molecular beam epitaxy,” Superlattices Microstruct.42(1-6), 129–133 (2007).
[CrossRef]

Chen, P. J.

S. Y. Ting, P. J. Chen, H. C. Wang, C. H. Liao, W. M. Chang, Y. P. Hsieh, and C. C. Yang, “Crystallinity improvement of ZnO thin film on different buffer layers grown by MBE,” J. Nanomater.2012, 6 (2012), doi:.
[CrossRef]

Chen, Y.

Y. Chen, F. Jiang, L. Wang, C. Zheng, J. Dai, Y. Pu, and W. Fang, “Structural and luminescent properties of ZnO epitaxial film grown on Si(111) substrate by atmospheric-pressure MOCVD,” J. Cryst. Growth275(3-4), 486–491 (2005).
[CrossRef]

Y. Chen, S. K. Hong, H. J. Ko, V. Kirshner, H. Wenisch, T. Yao, K. Inaba, and Y. Segawa, “Effects of an extremely thin buffer on heteroepitaxy with large lattice mismatch,” Appl. Phys. Lett.78(21), 3352–3354 (2001).
[CrossRef]

Y. Chen, H. J. Ko, S. K. Hong, and T. Yao, “Layer-by-layer growth of ZnO epilayer on Al2O3 (0001) by using a MgO buffer layer,” Appl. Phys. Lett.76(5), 559–561 (2000).
[CrossRef]

Chen, Y. F.

D. M. Bagnall, Y. F. Chen, Z. Zhu, T. Yao, S. Koyama, M. Y. Shen, and T. Goto, “Optically pumped lasing of ZnO at room temperature,” Appl. Phys. Lett.70(17), 2230–2232 (1997).
[CrossRef]

Chen, Y. J.

Y. J. Chen, Y. Y. Shih, C. H. Ho, J. H. Du, and Y. P. Fu, “Effect of temperature on lateral growth of ZnO grains grown by MOCVD,” Ceram. Int.36(1), 69–73 (2010).
[CrossRef]

Chia, C. H.

T. Makino, K. Tamura, C. H. Chia, Y. Segawa, M. Kawasaki, A. Ohtomo, and H. Koinuma, “Effect of MgZnO-layer capping on optical properties of ZnO epitaxial layers,” Appl. Phys. Lett.81(12), 2172–2174 (2002).
[CrossRef]

T. Makino, N. T. Tuan, H. D. Sun, C. H. Chia, Y. Segawa, M. Kawasaki, A. Ohtomo, K. Tamura, T. Suemoto, H. Akiyama, M. Baba, S. Saito, T. Tomita, and H. Koinuma, “Temperature dependence of near ultraviolet photoluminescence in ZnO/(Mg,Zn)O multiple quantum wells,” Appl. Phys. Lett.78(14), 1979–1981 (2001).
[CrossRef]

T. Makino, C. H. Chia, N. T. Tuan, H. D. Sun, Y. Segawa, M. Kawasaki, A. Ohtomo, K. Tamura, and H. Koinuma, “Room-temperature luminescence of excitons in ZnO/(Mg,Zn) O multiple quantum wells on lattice-matched substrates,” Appl. Phys. Lett.77(7), 975–977 (2000).
[CrossRef]

Christen, J.

T. Gruber, C. Kirchner, R. Kling, F. Reuss, A. Waag, F. Bertram, D. Forster, J. Christen, and M. Schreck, “Optical and structural analysis of ZnCdO layers grown by metalorganic vapor-phase epitaxy,” Appl. Phys. Lett.83(16), 3290–3292 (2003).
[CrossRef]

Chung, R. B.

R. B. Chung, F. Wu, R. Shivaraman, S. Keller, S. P. DenBaars, J. S. Speck, and S. Nakamura, “Growth study and ipurity characterization of AlxIn1−xN grown by metal organic chemical vapor deposition,” J. Cryst. Growth324(1), 163–167 (2011).
[CrossRef]

Coleman, V. A.

V. A. Coleman, M. Buda, H. H. Tan, C. Jagadish, M. R. Phillips, K. Koike, S. Sasa, M. Inoue, and M. Yano, “Observation of blue shifts in ZnO/ZnMgO multiple quantum well structures by ion-implantation induced intermixing,” Semicond. Sci. Technol.21(3), L25–L28 (2006).
[CrossRef]

Coli, G.

G. Coli and K. K. Bajaj, “Excitonic transitions in ZnO/MgZnO quantum well heterostructures,” Appl. Phys. Lett.78(19), 2861–2863 (2001).
[CrossRef]

Correia, M. R.

S. Pereira, M. R. Correia, E. Pereira, C. Trager-Cowan, F. Sweeney, K. P. O’Donnell, E. Alves, N. Franco, and A. D. Sequeira, “Structural and optical properties of InGaN/GaN layers close to the critical layer thickness,” Appl. Phys. Lett.81(7), 1207–1209 (2002).
[CrossRef]

Dai, J.

Y. Chen, F. Jiang, L. Wang, C. Zheng, J. Dai, Y. Pu, and W. Fang, “Structural and luminescent properties of ZnO epitaxial film grown on Si(111) substrate by atmospheric-pressure MOCVD,” J. Cryst. Growth275(3-4), 486–491 (2005).
[CrossRef]

Dal Negro, L.

E. Francesco Pecora, W. Zhang, A. Yu. Nikiforov, L. Zhou, D. J. Smith, J. Yin, R. Paiella, L. Dal Negro, and T. D. Moustakas, “Sub-250 nm room-temperature optical gain from AlGaN/AlN multiple quantum wells with strong band-structure potential fluctuations,” Appl. Phys. Lett.100(6), 061111 (2012).
[CrossRef]

Dao, L. V.

C. R. Hall, L. V. Dao, K. Koike, S. Sasa, H. H. Tan, M. Inoue, M. Yano, C. Jagadish, and J. A. Davis, “Using graded barriers to control the optical properties of ZnO/Zn0.7Mg0.3O quantum wells with an intrinsic internal electric field,” Appl. Phys. Lett.96(19), 193117 (2010).
[CrossRef]

Davis, J. A.

C. R. Hall, L. V. Dao, K. Koike, S. Sasa, H. H. Tan, M. Inoue, M. Yano, C. Jagadish, and J. A. Davis, “Using graded barriers to control the optical properties of ZnO/Zn0.7Mg0.3O quantum wells with an intrinsic internal electric field,” Appl. Phys. Lett.96(19), 193117 (2010).
[CrossRef]

DenBaars, S. P.

R. B. Chung, F. Wu, R. Shivaraman, S. Keller, S. P. DenBaars, J. S. Speck, and S. Nakamura, “Growth study and ipurity characterization of AlxIn1−xN grown by metal organic chemical vapor deposition,” J. Cryst. Growth324(1), 163–167 (2011).
[CrossRef]

Dierolf, V.

H. P. Zhao, G. Y. Liu, J. Zhang, J. D. Poplawsky, V. Dierolf, and N. Tansu, “Approaches for high internal quantum efficiency green InGaN light-emitting diodes with large overlap quantum wells,” Opt. Express19(S4Suppl 4), A991–A1007 (2011).
[CrossRef] [PubMed]

H. P. Zhao, G. Y. Liu, X. H. Li, R. A. Arif, G. S. Huang, J. D. Poplawsky, S. Tafon Penn, V. Dierolf, and N. Tansu, “Design and characteristics of staggered InGaN quantum well light-emitting diodes in the green spectral regimes,” IET Optoelectron.3(6), 283–295 (2009).
[CrossRef]

Du, J. H.

Y. J. Chen, Y. Y. Shih, C. H. Ho, J. H. Du, and Y. P. Fu, “Effect of temperature on lateral growth of ZnO grains grown by MOCVD,” Ceram. Int.36(1), 69–73 (2010).
[CrossRef]

Ee, Y.-K.

R. A. Arif, Y.-K. Ee, and N. Tansu, “Polarization engineering via staggered InGaN quantum wells for radiative efficiency enhancement of light emitting diodes,” Appl. Phys. Lett.91(9), 091110 (2007).
[CrossRef]

Egelhoff, W. F.

S. Y. O, C.-G. Lee, A. J. Shapiro, W. F. Egelhoff, M. D. Vaudin, J. L. Ruglovsky, J. Mallett, and P. W. T. Pong, “X-ray diffraction study of the optimization of MgO growth conditions for magnetic tunnel junctions,” J. Appl. Phys.103(7), 07A920 (2008).
[CrossRef]

El-Shaer, A.

A. Bakin, J. Kioseoglou, B. Pecz, A. El-Shaer, A.-C. Mofor, J. Stoemenos, and A. Waag, “Misfit reduction by a spinel layer formed during the epitaxial growth of ZnO on sapphire using a MgO buffer layer,” J. Cryst. Growth308(2), 314–320 (2007).
[CrossRef]

A. El-Shaer, A. Bakin, M. Al-Suleiman, S. Ivanov, A. Che Mofor, and A. Waag, “Growth of wide band gap wurtzite ZnMgO layers on (0001) Al2O3 by radical-source molecular beam epitaxy,” Superlattices Microstruct.42(1-6), 129–133 (2007).
[CrossRef]

A. Bakin, J. Kioseoglou, B. Pecz, A. El-Shaer, A.-C. Mofor, J. Stoemenos, and A. Waag, “Misfit reduction by a spinel layer formed during the epitaxial growth of ZnO on sapphire using a MgO buffer layer,” J. Cryst. Growth308(2), 314–320 (2007).
[CrossRef]

Evans, K. R.

G. Liu, J. Zhang, X. H. Li, G. S. Huang, T. Paskova, K. R. Evans, H. Zhao, and N. Tansu, “Metalorganic vapor phase epitaxy and characterizations of nearly-lattice-matched AlInN alloys on GaN/sapphire templates and free-standing GaN substrates,” J. Cryst. Growth340(1), 66–73 (2012).
[CrossRef]

Fang, G.

H. Long, G. Fang, S. Li, X. Mo, H. Wang, H. Huang, Q. Jiang, J. Wang, and X. Zhao, “A ZnO/ZnMgO multiple-quantum-well ultraviolet random laser diode,” IEEE Electron Device Lett.32(1), 54–56 (2011).
[CrossRef]

Fang, W.

Y. Chen, F. Jiang, L. Wang, C. Zheng, J. Dai, Y. Pu, and W. Fang, “Structural and luminescent properties of ZnO epitaxial film grown on Si(111) substrate by atmospheric-pressure MOCVD,” J. Cryst. Growth275(3-4), 486–491 (2005).
[CrossRef]

Ferret, P.

R. Thierry, G. Perillat-Merceroz, P. H. Jouneau, P. Ferret, and G. Feuillet, “Core-shell multi-quantum wells in ZnO/ZnMgO nanowires with high optical efficiency at room temperature,” Nanotechnology23(8), 085705 (2012).
[CrossRef] [PubMed]

Feuillet, G.

R. Thierry, G. Perillat-Merceroz, P. H. Jouneau, P. Ferret, and G. Feuillet, “Core-shell multi-quantum wells in ZnO/ZnMgO nanowires with high optical efficiency at room temperature,” Nanotechnology23(8), 085705 (2012).
[CrossRef] [PubMed]

Forster, D.

T. Gruber, C. Kirchner, R. Kling, F. Reuss, A. Waag, F. Bertram, D. Forster, J. Christen, and M. Schreck, “Optical and structural analysis of ZnCdO layers grown by metalorganic vapor-phase epitaxy,” Appl. Phys. Lett.83(16), 3290–3292 (2003).
[CrossRef]

Francesco Pecora, E.

E. Francesco Pecora, W. Zhang, A. Yu. Nikiforov, L. Zhou, D. J. Smith, J. Yin, R. Paiella, L. Dal Negro, and T. D. Moustakas, “Sub-250 nm room-temperature optical gain from AlGaN/AlN multiple quantum wells with strong band-structure potential fluctuations,” Appl. Phys. Lett.100(6), 061111 (2012).
[CrossRef]

Franco, N.

S. Pereira, M. R. Correia, E. Pereira, C. Trager-Cowan, F. Sweeney, K. P. O’Donnell, E. Alves, N. Franco, and A. D. Sequeira, “Structural and optical properties of InGaN/GaN layers close to the critical layer thickness,” Appl. Phys. Lett.81(7), 1207–1209 (2002).
[CrossRef]

Fu, Y. P.

Y. J. Chen, Y. Y. Shih, C. H. Ho, J. H. Du, and Y. P. Fu, “Effect of temperature on lateral growth of ZnO grains grown by MOCVD,” Ceram. Int.36(1), 69–73 (2010).
[CrossRef]

Fujimoto, K.

K. Koike, G. Y. Takada, K. Fujimoto, S. Sasa, M. Inoue, and M. Yano, “Characterization of [ZnO]m[ZnMgO]n multiple quantum wells grown by molecular beam epitaxy,” Physica E32(1-2), 191–194 (2006).
[CrossRef]

Goto, T.

D. M. Bagnall, Y. F. Chen, Z. Zhu, T. Yao, S. Koyama, M. Y. Shen, and T. Goto, “Optically pumped lasing of ZnO at room temperature,” Appl. Phys. Lett.70(17), 2230–2232 (1997).
[CrossRef]

Gruber, T.

T. Gruber, C. Kirchner, R. Kling, F. Reuss, and A. Waag, “ZnMgO epilayers and ZnO-ZnMgO quantum wells for optoelectronic applications in the blue and UV spectral region,” Appl. Phys. Lett.84(26), 5359–5361 (2004).
[CrossRef]

T. Gruber, C. Kirchner, R. Kling, F. Reuss, A. Waag, F. Bertram, D. Forster, J. Christen, and M. Schreck, “Optical and structural analysis of ZnCdO layers grown by metalorganic vapor-phase epitaxy,” Appl. Phys. Lett.83(16), 3290–3292 (2003).
[CrossRef]

Grundmann, M.

M. Brandt, H. Wenckstern, M. Stölzel, H. Hochmuth, M. Lorenz, and M. Grundmann, “Semiconducting oxide heterostructures,” Semicond. Sci. Technol.26(1), 014040 (2011).
[CrossRef]

M. Brandt, M. Lange, M. Stölzel, A. Müller, G. Benndorf, J. Zippel, J. Lenzner, M. Lorenz, and M. Grundmann, “Control of interface abruptness of polar MgZnO/ZnO quantum wells grown by pulsed laser deposition,” Appl. Phys. Lett.97(5), 052101 (2010).
[CrossRef]

Gu, X. Q.

X. Q. Gu, L. P. Zhu, Z. Z. Ye, H. P. He, Y. Z. Zhang, F. Huang, M. X. Qiu, Y. J. Zeng, F. Liu, and W. Jaeger, “Room-temperature photoluminescence from ZnO/ZnMgO multiple quantum wells grown on Si(111) substrates,” Appl. Phys. Lett.91(2), 022103 (2007).
[CrossRef]

Hall, C. R.

C. R. Hall, L. V. Dao, K. Koike, S. Sasa, H. H. Tan, M. Inoue, M. Yano, C. Jagadish, and J. A. Davis, “Using graded barriers to control the optical properties of ZnO/Zn0.7Mg0.3O quantum wells with an intrinsic internal electric field,” Appl. Phys. Lett.96(19), 193117 (2010).
[CrossRef]

Han, S. K.

J. G. Kim, S. K. Han, S. M. Yang, S. K. Hong, J. W. Lee, J. Y. Lee, J. H. Song, Y. E. Ihm, D. Kim, J. S. Park, H. J. Lee, and T. Yao, “Effects of low temperature ZnO and MgO buffer thicknesses on properties of ZnO films grown on (0001) Al2O3 substrates by plasma-assisted molecular beam epitaxy,” Thin Solid Films519(1), 223–227 (2010).
[CrossRef]

Hao, M.

T. Sugahara, M. Hao, T. Wang, D. Nakagawa, Y. Naoi, K. Nishino, and S. Sakai, “Role of dislocation in InGaN phase separation,” Jpn. J. Appl. Phys. Part 237(Part 2, No. 10B), L1195–L1198 (1998).
[CrossRef]

Harima, H.

H. Matsui, H. Tabata, N. Hasuike, and H. Harima, “Critical thickness and lattice relaxation of Mg-rich strained Mg0.37Zn0.63O (0001) layers towards multi-quantum-wells,” J. Appl. Phys.99(2), 024902 (2006).
[CrossRef]

H. Matsui, H. Tabata, N. Hasuike, and H. Harima, “Critical thickness and lattice relaxation of Mg-rich strained Mg0.37Zn0.63O (0001) layers towards multi-quantum-wells,” J. Appl. Phys.99(2), 024902 (2006).
[CrossRef]

Hashimoto, K.

K. Koike, I. Nakashima, K. Hashimoto, S. Sasa, M. Inoue, and M. Yano, “Characteristics of a Zn0.7Mg0.3O/ZnO heterostructure field-effect transistor grown on sapphire substrate by molecular-beam epitaxy,” Appl. Phys. Lett.87(11), 112106 (2005).
[CrossRef]

Hasuike, N.

H. Matsui, H. Tabata, N. Hasuike, and H. Harima, “Critical thickness and lattice relaxation of Mg-rich strained Mg0.37Zn0.63O (0001) layers towards multi-quantum-wells,” J. Appl. Phys.99(2), 024902 (2006).
[CrossRef]

H. Matsui, H. Tabata, N. Hasuike, and H. Harima, “Critical thickness and lattice relaxation of Mg-rich strained Mg0.37Zn0.63O (0001) layers towards multi-quantum-wells,” J. Appl. Phys.99(2), 024902 (2006).
[CrossRef]

He, H.

K. Wu, H. He, Y. Lu, J. Huang, and Z. Ye, “Dominant free exciton emission in ZnO nanorods,” Nanoscale4(5), 1701–1706 (2012).
[CrossRef] [PubMed]

He, H. P.

X. Q. Gu, L. P. Zhu, Z. Z. Ye, H. P. He, Y. Z. Zhang, F. Huang, M. X. Qiu, Y. J. Zeng, F. Liu, and W. Jaeger, “Room-temperature photoluminescence from ZnO/ZnMgO multiple quantum wells grown on Si(111) substrates,” Appl. Phys. Lett.91(2), 022103 (2007).
[CrossRef]

Hiramatsu, K.

M. Shimizu, Y. Kawaguchi, K. Hiramatsu, and N. Sawaki, “Metalorganic vapor phase epitaxy of thick InGaN on sapphire substrate,” Jpn. J. Appl. Phys. Part 136(Part 1, No. 6A), 3381–3384 (1997).
[CrossRef]

Ho, C. H.

Y. J. Chen, Y. Y. Shih, C. H. Ho, J. H. Du, and Y. P. Fu, “Effect of temperature on lateral growth of ZnO grains grown by MOCVD,” Ceram. Int.36(1), 69–73 (2010).
[CrossRef]

Hochmuth, H.

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Y. Chen, H. J. Ko, S. K. Hong, and T. Yao, “Layer-by-layer growth of ZnO epilayer on Al2O3 (0001) by using a MgO buffer layer,” Appl. Phys. Lett.76(5), 559–561 (2000).
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[CrossRef]

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[CrossRef]

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[CrossRef]

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[CrossRef]

T. Makino, C. H. Chia, N. T. Tuan, H. D. Sun, Y. Segawa, M. Kawasaki, A. Ohtomo, K. Tamura, and H. Koinuma, “Room-temperature luminescence of excitons in ZnO/(Mg,Zn) O multiple quantum wells on lattice-matched substrates,” Appl. Phys. Lett.77(7), 975–977 (2000).
[CrossRef]

A. Ohtomo, M. Kawasaki, T. Koida, K. Masubuchi, H. Koinuma, Y. Sakurai, Y. Yoshida, T. Yasuda, and Y. Segawa, “MgxZn1−xO as a II–VI widegap semiconductor alloy,” Appl. Phys. Lett.72(19), 2466–2468 (1998).
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J. G. Kim, S. K. Han, S. M. Yang, S. K. Hong, J. W. Lee, J. Y. Lee, J. H. Song, Y. E. Ihm, D. Kim, J. S. Park, H. J. Lee, and T. Yao, “Effects of low temperature ZnO and MgO buffer thicknesses on properties of ZnO films grown on (0001) Al2O3 substrates by plasma-assisted molecular beam epitaxy,” Thin Solid Films519(1), 223–227 (2010).
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J. G. Kim, S. K. Han, S. M. Yang, S. K. Hong, J. W. Lee, J. Y. Lee, J. H. Song, Y. E. Ihm, D. Kim, J. S. Park, H. J. Lee, and T. Yao, “Effects of low temperature ZnO and MgO buffer thicknesses on properties of ZnO films grown on (0001) Al2O3 substrates by plasma-assisted molecular beam epitaxy,” Thin Solid Films519(1), 223–227 (2010).
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X. Q. Gu, L. P. Zhu, Z. Z. Ye, H. P. He, Y. Z. Zhang, F. Huang, M. X. Qiu, Y. J. Zeng, F. Liu, and W. Jaeger, “Room-temperature photoluminescence from ZnO/ZnMgO multiple quantum wells grown on Si(111) substrates,” Appl. Phys. Lett.91(2), 022103 (2007).
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H. Long, G. Fang, S. Li, X. Mo, H. Wang, H. Huang, Q. Jiang, J. Wang, and X. Zhao, “A ZnO/ZnMgO multiple-quantum-well ultraviolet random laser diode,” IEEE Electron Device Lett.32(1), 54–56 (2011).
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K. Wu, H. He, Y. Lu, J. Huang, and Z. Ye, “Dominant free exciton emission in ZnO nanorods,” Nanoscale4(5), 1701–1706 (2012).
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T. Makino, Y. Segawa, M. Kawasaki, and H. Koinuma, “Optical properties of excitons in ZnO-based quantum well heterostructures,” Semicond. Sci. Technol.20(4), S78–S91 (2005).
[CrossRef]

T. Makino, Y. Segawa, and M. Kawasaki, “Analytical study on exciton - longitudinal - optical - phonon coupling and comparison with experiment for ZnO quantum wells,” J. Appl. Phys.97(10), 106111 (2005).
[CrossRef]

T. Makino, K. Tamura, C. H. Chia, Y. Segawa, M. Kawasaki, A. Ohtomo, and H. Koinuma, “Effect of MgZnO-layer capping on optical properties of ZnO epitaxial layers,” Appl. Phys. Lett.81(12), 2172–2174 (2002).
[CrossRef]

T. Makino, N. T. Tuan, H. D. Sun, C. H. Chia, Y. Segawa, M. Kawasaki, A. Ohtomo, K. Tamura, T. Suemoto, H. Akiyama, M. Baba, S. Saito, T. Tomita, and H. Koinuma, “Temperature dependence of near ultraviolet photoluminescence in ZnO/(Mg,Zn)O multiple quantum wells,” Appl. Phys. Lett.78(14), 1979–1981 (2001).
[CrossRef]

T. Makino, Y. Segawa, M. Kawasaki, A. Ohtomo, R. Shiroki, K. Tamura, T. Yasuda, and H. Koinuma, “Band gap engineering based on MgxZn1−xO and CdyZn1−yO ternary alloy films,” Appl. Phys. Lett.78(9), 1237–1239 (2001).
[CrossRef]

T. Makino, C. H. Chia, N. T. Tuan, H. D. Sun, Y. Segawa, M. Kawasaki, A. Ohtomo, K. Tamura, and H. Koinuma, “Room-temperature luminescence of excitons in ZnO/(Mg,Zn) O multiple quantum wells on lattice-matched substrates,” Appl. Phys. Lett.77(7), 975–977 (2000).
[CrossRef]

Mallett, J.

S. Y. O, C.-G. Lee, A. J. Shapiro, W. F. Egelhoff, M. D. Vaudin, J. L. Ruglovsky, J. Mallett, and P. W. T. Pong, “X-ray diffraction study of the optimization of MgO growth conditions for magnetic tunnel junctions,” J. Appl. Phys.103(7), 07A920 (2008).
[CrossRef]

Masubuchi, K.

A. Ohtomo, M. Kawasaki, T. Koida, K. Masubuchi, H. Koinuma, Y. Sakurai, Y. Yoshida, T. Yasuda, and Y. Segawa, “MgxZn1−xO as a II–VI widegap semiconductor alloy,” Appl. Phys. Lett.72(19), 2466–2468 (1998).
[CrossRef]

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H. Matsui, H. Tabata, N. Hasuike, and H. Harima, “Critical thickness and lattice relaxation of Mg-rich strained Mg0.37Zn0.63O (0001) layers towards multi-quantum-wells,” J. Appl. Phys.99(2), 024902 (2006).
[CrossRef]

H. Matsui, H. Tabata, N. Hasuike, and H. Harima, “Critical thickness and lattice relaxation of Mg-rich strained Mg0.37Zn0.63O (0001) layers towards multi-quantum-wells,” J. Appl. Phys.99(2), 024902 (2006).
[CrossRef]

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H. Kato, K. Miyamoto, M. Sano, and T. Yao, “Polarity control of ZnO on sapphire by varying the MgO buffer layer thickness,” Appl. Phys. Lett.84(22), 4562–4564 (2004).
[CrossRef]

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H. Long, G. Fang, S. Li, X. Mo, H. Wang, H. Huang, Q. Jiang, J. Wang, and X. Zhao, “A ZnO/ZnMgO multiple-quantum-well ultraviolet random laser diode,” IEEE Electron Device Lett.32(1), 54–56 (2011).
[CrossRef]

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A. Bakin, J. Kioseoglou, B. Pecz, A. El-Shaer, A.-C. Mofor, J. Stoemenos, and A. Waag, “Misfit reduction by a spinel layer formed during the epitaxial growth of ZnO on sapphire using a MgO buffer layer,” J. Cryst. Growth308(2), 314–320 (2007).
[CrossRef]

A. Bakin, J. Kioseoglou, B. Pecz, A. El-Shaer, A.-C. Mofor, J. Stoemenos, and A. Waag, “Misfit reduction by a spinel layer formed during the epitaxial growth of ZnO on sapphire using a MgO buffer layer,” J. Cryst. Growth308(2), 314–320 (2007).
[CrossRef]

Moustakas, T. D.

E. Francesco Pecora, W. Zhang, A. Yu. Nikiforov, L. Zhou, D. J. Smith, J. Yin, R. Paiella, L. Dal Negro, and T. D. Moustakas, “Sub-250 nm room-temperature optical gain from AlGaN/AlN multiple quantum wells with strong band-structure potential fluctuations,” Appl. Phys. Lett.100(6), 061111 (2012).
[CrossRef]

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M. Brandt, M. Lange, M. Stölzel, A. Müller, G. Benndorf, J. Zippel, J. Lenzner, M. Lorenz, and M. Grundmann, “Control of interface abruptness of polar MgZnO/ZnO quantum wells grown by pulsed laser deposition,” Appl. Phys. Lett.97(5), 052101 (2010).
[CrossRef]

Nakagawa, D.

T. Sugahara, M. Hao, T. Wang, D. Nakagawa, Y. Naoi, K. Nishino, and S. Sakai, “Role of dislocation in InGaN phase separation,” Jpn. J. Appl. Phys. Part 237(Part 2, No. 10B), L1195–L1198 (1998).
[CrossRef]

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R. B. Chung, F. Wu, R. Shivaraman, S. Keller, S. P. DenBaars, J. S. Speck, and S. Nakamura, “Growth study and ipurity characterization of AlxIn1−xN grown by metal organic chemical vapor deposition,” J. Cryst. Growth324(1), 163–167 (2011).
[CrossRef]

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K. Koike, I. Nakashima, K. Hashimoto, S. Sasa, M. Inoue, and M. Yano, “Characteristics of a Zn0.7Mg0.3O/ZnO heterostructure field-effect transistor grown on sapphire substrate by molecular-beam epitaxy,” Appl. Phys. Lett.87(11), 112106 (2005).
[CrossRef]

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T. Sugahara, M. Hao, T. Wang, D. Nakagawa, Y. Naoi, K. Nishino, and S. Sakai, “Role of dislocation in InGaN phase separation,” Jpn. J. Appl. Phys. Part 237(Part 2, No. 10B), L1195–L1198 (1998).
[CrossRef]

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T. Sugahara, M. Hao, T. Wang, D. Nakagawa, Y. Naoi, K. Nishino, and S. Sakai, “Role of dislocation in InGaN phase separation,” Jpn. J. Appl. Phys. Part 237(Part 2, No. 10B), L1195–L1198 (1998).
[CrossRef]

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S. Y. O, C.-G. Lee, A. J. Shapiro, W. F. Egelhoff, M. D. Vaudin, J. L. Ruglovsky, J. Mallett, and P. W. T. Pong, “X-ray diffraction study of the optimization of MgO growth conditions for magnetic tunnel junctions,” J. Appl. Phys.103(7), 07A920 (2008).
[CrossRef]

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S. Pereira, M. R. Correia, E. Pereira, C. Trager-Cowan, F. Sweeney, K. P. O’Donnell, E. Alves, N. Franco, and A. D. Sequeira, “Structural and optical properties of InGaN/GaN layers close to the critical layer thickness,” Appl. Phys. Lett.81(7), 1207–1209 (2002).
[CrossRef]

Ohtomo, A.

D. Sun, Y. Segawa, M. Kawasaki, A. Ohtomo, K. Tamura, and H. Koinuma, “Phonon replicas in ZnO/ZnMgO multiquantum wells,” J. Appl. Phys.91(10), 6457–6460 (2002).
[CrossRef]

T. Makino, K. Tamura, C. H. Chia, Y. Segawa, M. Kawasaki, A. Ohtomo, and H. Koinuma, “Effect of MgZnO-layer capping on optical properties of ZnO epitaxial layers,” Appl. Phys. Lett.81(12), 2172–2174 (2002).
[CrossRef]

T. Makino, N. T. Tuan, H. D. Sun, C. H. Chia, Y. Segawa, M. Kawasaki, A. Ohtomo, K. Tamura, T. Suemoto, H. Akiyama, M. Baba, S. Saito, T. Tomita, and H. Koinuma, “Temperature dependence of near ultraviolet photoluminescence in ZnO/(Mg,Zn)O multiple quantum wells,” Appl. Phys. Lett.78(14), 1979–1981 (2001).
[CrossRef]

T. Makino, Y. Segawa, M. Kawasaki, A. Ohtomo, R. Shiroki, K. Tamura, T. Yasuda, and H. Koinuma, “Band gap engineering based on MgxZn1−xO and CdyZn1−yO ternary alloy films,” Appl. Phys. Lett.78(9), 1237–1239 (2001).
[CrossRef]

T. Makino, C. H. Chia, N. T. Tuan, H. D. Sun, Y. Segawa, M. Kawasaki, A. Ohtomo, K. Tamura, and H. Koinuma, “Room-temperature luminescence of excitons in ZnO/(Mg,Zn) O multiple quantum wells on lattice-matched substrates,” Appl. Phys. Lett.77(7), 975–977 (2000).
[CrossRef]

A. Ohtomo, M. Kawasaki, T. Koida, K. Masubuchi, H. Koinuma, Y. Sakurai, Y. Yoshida, T. Yasuda, and Y. Segawa, “MgxZn1−xO as a II–VI widegap semiconductor alloy,” Appl. Phys. Lett.72(19), 2466–2468 (1998).
[CrossRef]

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E. Francesco Pecora, W. Zhang, A. Yu. Nikiforov, L. Zhou, D. J. Smith, J. Yin, R. Paiella, L. Dal Negro, and T. D. Moustakas, “Sub-250 nm room-temperature optical gain from AlGaN/AlN multiple quantum wells with strong band-structure potential fluctuations,” Appl. Phys. Lett.100(6), 061111 (2012).
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J. H. Lim, C. K. Kang, K. K. Kim, I. K. Park, D. K. Hwang, and S. J. Park, “UV electroluminescence emission from ZnO light-emitting diodes grown by high-temperature radiofrequency sputtering,” Adv. Mater. 18(20), 2720–2724 (2006).
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J. G. Kim, S. K. Han, S. M. Yang, S. K. Hong, J. W. Lee, J. Y. Lee, J. H. Song, Y. E. Ihm, D. Kim, J. S. Park, H. J. Lee, and T. Yao, “Effects of low temperature ZnO and MgO buffer thicknesses on properties of ZnO films grown on (0001) Al2O3 substrates by plasma-assisted molecular beam epitaxy,” Thin Solid Films519(1), 223–227 (2010).
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J. H. Lim, C. K. Kang, K. K. Kim, I. K. Park, D. K. Hwang, and S. J. Park, “UV electroluminescence emission from ZnO light-emitting diodes grown by high-temperature radiofrequency sputtering,” Adv. Mater. 18(20), 2720–2724 (2006).
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W. I. Park, G. C. Yi, and H. M. Jang, “Metalorganic vapor-phase epitaxial growth and photoluminescent properties of Zn1−xMgxO(0 ≤ x ≤ 0.49) thin films,” Appl. Phys. Lett.79(13), 2022–2024 (2001).
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G. Liu, J. Zhang, X. H. Li, G. S. Huang, T. Paskova, K. R. Evans, H. Zhao, and N. Tansu, “Metalorganic vapor phase epitaxy and characterizations of nearly-lattice-matched AlInN alloys on GaN/sapphire templates and free-standing GaN substrates,” J. Cryst. Growth340(1), 66–73 (2012).
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A. Bakin, J. Kioseoglou, B. Pecz, A. El-Shaer, A.-C. Mofor, J. Stoemenos, and A. Waag, “Misfit reduction by a spinel layer formed during the epitaxial growth of ZnO on sapphire using a MgO buffer layer,” J. Cryst. Growth308(2), 314–320 (2007).
[CrossRef]

A. Bakin, J. Kioseoglou, B. Pecz, A. El-Shaer, A.-C. Mofor, J. Stoemenos, and A. Waag, “Misfit reduction by a spinel layer formed during the epitaxial growth of ZnO on sapphire using a MgO buffer layer,” J. Cryst. Growth308(2), 314–320 (2007).
[CrossRef]

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S. Pereira, M. R. Correia, E. Pereira, C. Trager-Cowan, F. Sweeney, K. P. O’Donnell, E. Alves, N. Franco, and A. D. Sequeira, “Structural and optical properties of InGaN/GaN layers close to the critical layer thickness,” Appl. Phys. Lett.81(7), 1207–1209 (2002).
[CrossRef]

Pereira, S.

S. Pereira, M. R. Correia, E. Pereira, C. Trager-Cowan, F. Sweeney, K. P. O’Donnell, E. Alves, N. Franco, and A. D. Sequeira, “Structural and optical properties of InGaN/GaN layers close to the critical layer thickness,” Appl. Phys. Lett.81(7), 1207–1209 (2002).
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R. Thierry, G. Perillat-Merceroz, P. H. Jouneau, P. Ferret, and G. Feuillet, “Core-shell multi-quantum wells in ZnO/ZnMgO nanowires with high optical efficiency at room temperature,” Nanotechnology23(8), 085705 (2012).
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V. A. Coleman, M. Buda, H. H. Tan, C. Jagadish, M. R. Phillips, K. Koike, S. Sasa, M. Inoue, and M. Yano, “Observation of blue shifts in ZnO/ZnMgO multiple quantum well structures by ion-implantation induced intermixing,” Semicond. Sci. Technol.21(3), L25–L28 (2006).
[CrossRef]

Pong, P. W. T.

S. Y. O, C.-G. Lee, A. J. Shapiro, W. F. Egelhoff, M. D. Vaudin, J. L. Ruglovsky, J. Mallett, and P. W. T. Pong, “X-ray diffraction study of the optimization of MgO growth conditions for magnetic tunnel junctions,” J. Appl. Phys.103(7), 07A920 (2008).
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H. P. Zhao, G. Y. Liu, J. Zhang, J. D. Poplawsky, V. Dierolf, and N. Tansu, “Approaches for high internal quantum efficiency green InGaN light-emitting diodes with large overlap quantum wells,” Opt. Express19(S4Suppl 4), A991–A1007 (2011).
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H. P. Zhao, G. Y. Liu, X. H. Li, R. A. Arif, G. S. Huang, J. D. Poplawsky, S. Tafon Penn, V. Dierolf, and N. Tansu, “Design and characteristics of staggered InGaN quantum well light-emitting diodes in the green spectral regimes,” IET Optoelectron.3(6), 283–295 (2009).
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Y. Chen, F. Jiang, L. Wang, C. Zheng, J. Dai, Y. Pu, and W. Fang, “Structural and luminescent properties of ZnO epitaxial film grown on Si(111) substrate by atmospheric-pressure MOCVD,” J. Cryst. Growth275(3-4), 486–491 (2005).
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X. Q. Gu, L. P. Zhu, Z. Z. Ye, H. P. He, Y. Z. Zhang, F. Huang, M. X. Qiu, Y. J. Zeng, F. Liu, and W. Jaeger, “Room-temperature photoluminescence from ZnO/ZnMgO multiple quantum wells grown on Si(111) substrates,” Appl. Phys. Lett.91(2), 022103 (2007).
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Reuss, F.

T. Gruber, C. Kirchner, R. Kling, F. Reuss, and A. Waag, “ZnMgO epilayers and ZnO-ZnMgO quantum wells for optoelectronic applications in the blue and UV spectral region,” Appl. Phys. Lett.84(26), 5359–5361 (2004).
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T. Gruber, C. Kirchner, R. Kling, F. Reuss, A. Waag, F. Bertram, D. Forster, J. Christen, and M. Schreck, “Optical and structural analysis of ZnCdO layers grown by metalorganic vapor-phase epitaxy,” Appl. Phys. Lett.83(16), 3290–3292 (2003).
[CrossRef]

Ruglovsky, J. L.

S. Y. O, C.-G. Lee, A. J. Shapiro, W. F. Egelhoff, M. D. Vaudin, J. L. Ruglovsky, J. Mallett, and P. W. T. Pong, “X-ray diffraction study of the optimization of MgO growth conditions for magnetic tunnel junctions,” J. Appl. Phys.103(7), 07A920 (2008).
[CrossRef]

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T. Makino, N. T. Tuan, H. D. Sun, C. H. Chia, Y. Segawa, M. Kawasaki, A. Ohtomo, K. Tamura, T. Suemoto, H. Akiyama, M. Baba, S. Saito, T. Tomita, and H. Koinuma, “Temperature dependence of near ultraviolet photoluminescence in ZnO/(Mg,Zn)O multiple quantum wells,” Appl. Phys. Lett.78(14), 1979–1981 (2001).
[CrossRef]

Sakai, S.

T. Sugahara, M. Hao, T. Wang, D. Nakagawa, Y. Naoi, K. Nishino, and S. Sakai, “Role of dislocation in InGaN phase separation,” Jpn. J. Appl. Phys. Part 237(Part 2, No. 10B), L1195–L1198 (1998).
[CrossRef]

Sakurai, Y.

A. Ohtomo, M. Kawasaki, T. Koida, K. Masubuchi, H. Koinuma, Y. Sakurai, Y. Yoshida, T. Yasuda, and Y. Segawa, “MgxZn1−xO as a II–VI widegap semiconductor alloy,” Appl. Phys. Lett.72(19), 2466–2468 (1998).
[CrossRef]

Sano, M.

H. Kato, K. Miyamoto, M. Sano, and T. Yao, “Polarity control of ZnO on sapphire by varying the MgO buffer layer thickness,” Appl. Phys. Lett.84(22), 4562–4564 (2004).
[CrossRef]

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C. R. Hall, L. V. Dao, K. Koike, S. Sasa, H. H. Tan, M. Inoue, M. Yano, C. Jagadish, and J. A. Davis, “Using graded barriers to control the optical properties of ZnO/Zn0.7Mg0.3O quantum wells with an intrinsic internal electric field,” Appl. Phys. Lett.96(19), 193117 (2010).
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K. Koike, G. Y. Takada, K. Fujimoto, S. Sasa, M. Inoue, and M. Yano, “Characterization of [ZnO]m[ZnMgO]n multiple quantum wells grown by molecular beam epitaxy,” Physica E32(1-2), 191–194 (2006).
[CrossRef]

V. A. Coleman, M. Buda, H. H. Tan, C. Jagadish, M. R. Phillips, K. Koike, S. Sasa, M. Inoue, and M. Yano, “Observation of blue shifts in ZnO/ZnMgO multiple quantum well structures by ion-implantation induced intermixing,” Semicond. Sci. Technol.21(3), L25–L28 (2006).
[CrossRef]

K. Koike, I. Nakashima, K. Hashimoto, S. Sasa, M. Inoue, and M. Yano, “Characteristics of a Zn0.7Mg0.3O/ZnO heterostructure field-effect transistor grown on sapphire substrate by molecular-beam epitaxy,” Appl. Phys. Lett.87(11), 112106 (2005).
[CrossRef]

Sawaki, N.

M. Shimizu, Y. Kawaguchi, K. Hiramatsu, and N. Sawaki, “Metalorganic vapor phase epitaxy of thick InGaN on sapphire substrate,” Jpn. J. Appl. Phys. Part 136(Part 1, No. 6A), 3381–3384 (1997).
[CrossRef]

Schreck, M.

T. Gruber, C. Kirchner, R. Kling, F. Reuss, A. Waag, F. Bertram, D. Forster, J. Christen, and M. Schreck, “Optical and structural analysis of ZnCdO layers grown by metalorganic vapor-phase epitaxy,” Appl. Phys. Lett.83(16), 3290–3292 (2003).
[CrossRef]

Segawa, Y.

T. Makino, Y. Segawa, and M. Kawasaki, “Analytical study on exciton - longitudinal - optical - phonon coupling and comparison with experiment for ZnO quantum wells,” J. Appl. Phys.97(10), 106111 (2005).
[CrossRef]

T. Makino, Y. Segawa, M. Kawasaki, and H. Koinuma, “Optical properties of excitons in ZnO-based quantum well heterostructures,” Semicond. Sci. Technol.20(4), S78–S91 (2005).
[CrossRef]

D. Sun, Y. Segawa, M. Kawasaki, A. Ohtomo, K. Tamura, and H. Koinuma, “Phonon replicas in ZnO/ZnMgO multiquantum wells,” J. Appl. Phys.91(10), 6457–6460 (2002).
[CrossRef]

T. Makino, K. Tamura, C. H. Chia, Y. Segawa, M. Kawasaki, A. Ohtomo, and H. Koinuma, “Effect of MgZnO-layer capping on optical properties of ZnO epitaxial layers,” Appl. Phys. Lett.81(12), 2172–2174 (2002).
[CrossRef]

T. Makino, N. T. Tuan, H. D. Sun, C. H. Chia, Y. Segawa, M. Kawasaki, A. Ohtomo, K. Tamura, T. Suemoto, H. Akiyama, M. Baba, S. Saito, T. Tomita, and H. Koinuma, “Temperature dependence of near ultraviolet photoluminescence in ZnO/(Mg,Zn)O multiple quantum wells,” Appl. Phys. Lett.78(14), 1979–1981 (2001).
[CrossRef]

Y. Chen, S. K. Hong, H. J. Ko, V. Kirshner, H. Wenisch, T. Yao, K. Inaba, and Y. Segawa, “Effects of an extremely thin buffer on heteroepitaxy with large lattice mismatch,” Appl. Phys. Lett.78(21), 3352–3354 (2001).
[CrossRef]

T. Makino, Y. Segawa, M. Kawasaki, A. Ohtomo, R. Shiroki, K. Tamura, T. Yasuda, and H. Koinuma, “Band gap engineering based on MgxZn1−xO and CdyZn1−yO ternary alloy films,” Appl. Phys. Lett.78(9), 1237–1239 (2001).
[CrossRef]

T. Makino, C. H. Chia, N. T. Tuan, H. D. Sun, Y. Segawa, M. Kawasaki, A. Ohtomo, K. Tamura, and H. Koinuma, “Room-temperature luminescence of excitons in ZnO/(Mg,Zn) O multiple quantum wells on lattice-matched substrates,” Appl. Phys. Lett.77(7), 975–977 (2000).
[CrossRef]

A. Ohtomo, M. Kawasaki, T. Koida, K. Masubuchi, H. Koinuma, Y. Sakurai, Y. Yoshida, T. Yasuda, and Y. Segawa, “MgxZn1−xO as a II–VI widegap semiconductor alloy,” Appl. Phys. Lett.72(19), 2466–2468 (1998).
[CrossRef]

Sequeira, A. D.

S. Pereira, M. R. Correia, E. Pereira, C. Trager-Cowan, F. Sweeney, K. P. O’Donnell, E. Alves, N. Franco, and A. D. Sequeira, “Structural and optical properties of InGaN/GaN layers close to the critical layer thickness,” Appl. Phys. Lett.81(7), 1207–1209 (2002).
[CrossRef]

Shapiro, A. J.

S. Y. O, C.-G. Lee, A. J. Shapiro, W. F. Egelhoff, M. D. Vaudin, J. L. Ruglovsky, J. Mallett, and P. W. T. Pong, “X-ray diffraction study of the optimization of MgO growth conditions for magnetic tunnel junctions,” J. Appl. Phys.103(7), 07A920 (2008).
[CrossRef]

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D. M. Bagnall, Y. F. Chen, Z. Zhu, T. Yao, S. Koyama, M. Y. Shen, and T. Goto, “Optically pumped lasing of ZnO at room temperature,” Appl. Phys. Lett.70(17), 2230–2232 (1997).
[CrossRef]

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Y. J. Chen, Y. Y. Shih, C. H. Ho, J. H. Du, and Y. P. Fu, “Effect of temperature on lateral growth of ZnO grains grown by MOCVD,” Ceram. Int.36(1), 69–73 (2010).
[CrossRef]

Shimizu, M.

M. Shimizu, Y. Kawaguchi, K. Hiramatsu, and N. Sawaki, “Metalorganic vapor phase epitaxy of thick InGaN on sapphire substrate,” Jpn. J. Appl. Phys. Part 136(Part 1, No. 6A), 3381–3384 (1997).
[CrossRef]

Shiroki, R.

T. Makino, Y. Segawa, M. Kawasaki, A. Ohtomo, R. Shiroki, K. Tamura, T. Yasuda, and H. Koinuma, “Band gap engineering based on MgxZn1−xO and CdyZn1−yO ternary alloy films,” Appl. Phys. Lett.78(9), 1237–1239 (2001).
[CrossRef]

Shivaraman, R.

R. B. Chung, F. Wu, R. Shivaraman, S. Keller, S. P. DenBaars, J. S. Speck, and S. Nakamura, “Growth study and ipurity characterization of AlxIn1−xN grown by metal organic chemical vapor deposition,” J. Cryst. Growth324(1), 163–167 (2011).
[CrossRef]

Smith, D. J.

E. Francesco Pecora, W. Zhang, A. Yu. Nikiforov, L. Zhou, D. J. Smith, J. Yin, R. Paiella, L. Dal Negro, and T. D. Moustakas, “Sub-250 nm room-temperature optical gain from AlGaN/AlN multiple quantum wells with strong band-structure potential fluctuations,” Appl. Phys. Lett.100(6), 061111 (2012).
[CrossRef]

Song, J. H.

J. G. Kim, S. K. Han, S. M. Yang, S. K. Hong, J. W. Lee, J. Y. Lee, J. H. Song, Y. E. Ihm, D. Kim, J. S. Park, H. J. Lee, and T. Yao, “Effects of low temperature ZnO and MgO buffer thicknesses on properties of ZnO films grown on (0001) Al2O3 substrates by plasma-assisted molecular beam epitaxy,” Thin Solid Films519(1), 223–227 (2010).
[CrossRef]

Speck, J. S.

R. B. Chung, F. Wu, R. Shivaraman, S. Keller, S. P. DenBaars, J. S. Speck, and S. Nakamura, “Growth study and ipurity characterization of AlxIn1−xN grown by metal organic chemical vapor deposition,” J. Cryst. Growth324(1), 163–167 (2011).
[CrossRef]

Stoemenos, J.

A. Bakin, J. Kioseoglou, B. Pecz, A. El-Shaer, A.-C. Mofor, J. Stoemenos, and A. Waag, “Misfit reduction by a spinel layer formed during the epitaxial growth of ZnO on sapphire using a MgO buffer layer,” J. Cryst. Growth308(2), 314–320 (2007).
[CrossRef]

A. Bakin, J. Kioseoglou, B. Pecz, A. El-Shaer, A.-C. Mofor, J. Stoemenos, and A. Waag, “Misfit reduction by a spinel layer formed during the epitaxial growth of ZnO on sapphire using a MgO buffer layer,” J. Cryst. Growth308(2), 314–320 (2007).
[CrossRef]

Stölzel, M.

M. Brandt, H. Wenckstern, M. Stölzel, H. Hochmuth, M. Lorenz, and M. Grundmann, “Semiconducting oxide heterostructures,” Semicond. Sci. Technol.26(1), 014040 (2011).
[CrossRef]

M. Brandt, M. Lange, M. Stölzel, A. Müller, G. Benndorf, J. Zippel, J. Lenzner, M. Lorenz, and M. Grundmann, “Control of interface abruptness of polar MgZnO/ZnO quantum wells grown by pulsed laser deposition,” Appl. Phys. Lett.97(5), 052101 (2010).
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J. Zhang, H. Zhao, and N. Tansu, “Effect of crystal-field split-off hole and heavy-hole bands crossover on gain characteristics of high Al-content AlGaN quantum well lasers,” Appl. Phys. Lett.97(11), 111105 (2010).
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Y. Chen, F. Jiang, L. Wang, C. Zheng, J. Dai, Y. Pu, and W. Fang, “Structural and luminescent properties of ZnO epitaxial film grown on Si(111) substrate by atmospheric-pressure MOCVD,” J. Cryst. Growth275(3-4), 486–491 (2005).
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T. Sugahara, M. Hao, T. Wang, D. Nakagawa, Y. Naoi, K. Nishino, and S. Sakai, “Role of dislocation in InGaN phase separation,” Jpn. J. Appl. Phys. Part 237(Part 2, No. 10B), L1195–L1198 (1998).
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Y. Chen, H. J. Ko, S. K. Hong, and T. Yao, “Layer-by-layer growth of ZnO epilayer on Al2O3 (0001) by using a MgO buffer layer,” Appl. Phys. Lett.76(5), 559–561 (2000).
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T. Makino, Y. Segawa, M. Kawasaki, A. Ohtomo, R. Shiroki, K. Tamura, T. Yasuda, and H. Koinuma, “Band gap engineering based on MgxZn1−xO and CdyZn1−yO ternary alloy films,” Appl. Phys. Lett.78(9), 1237–1239 (2001).
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K. Wu, H. He, Y. Lu, J. Huang, and Z. Ye, “Dominant free exciton emission in ZnO nanorods,” Nanoscale4(5), 1701–1706 (2012).
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X. Q. Gu, L. P. Zhu, Z. Z. Ye, H. P. He, Y. Z. Zhang, F. Huang, M. X. Qiu, Y. J. Zeng, F. Liu, and W. Jaeger, “Room-temperature photoluminescence from ZnO/ZnMgO multiple quantum wells grown on Si(111) substrates,” Appl. Phys. Lett.91(2), 022103 (2007).
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W. I. Park, G. C. Yi, and H. M. Jang, “Metalorganic vapor-phase epitaxial growth and photoluminescent properties of Zn1−xMgxO(0 ≤ x ≤ 0.49) thin films,” Appl. Phys. Lett.79(13), 2022–2024 (2001).
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G. Liu, J. Zhang, X. H. Li, G. S. Huang, T. Paskova, K. R. Evans, H. Zhao, and N. Tansu, “Metalorganic vapor phase epitaxy and characterizations of nearly-lattice-matched AlInN alloys on GaN/sapphire templates and free-standing GaN substrates,” J. Cryst. Growth340(1), 66–73 (2012).
[CrossRef]

J. Zhang, H. Zhao, and N. Tansu, “Large optical gain AlGaN-delta-GaN quantum wells laser active regions in mid- and deep-ultraviolet spectral regimes,” Appl. Phys. Lett.98(17), 171111 (2011).
[CrossRef]

H. P. Zhao, G. Y. Liu, J. Zhang, J. D. Poplawsky, V. Dierolf, and N. Tansu, “Approaches for high internal quantum efficiency green InGaN light-emitting diodes with large overlap quantum wells,” Opt. Express19(S4Suppl 4), A991–A1007 (2011).
[CrossRef] [PubMed]

J. Zhang, H. Zhao, and N. Tansu, “Effect of crystal-field split-off hole and heavy-hole bands crossover on gain characteristics of high Al-content AlGaN quantum well lasers,” Appl. Phys. Lett.97(11), 111105 (2010).
[CrossRef]

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E. Francesco Pecora, W. Zhang, A. Yu. Nikiforov, L. Zhou, D. J. Smith, J. Yin, R. Paiella, L. Dal Negro, and T. D. Moustakas, “Sub-250 nm room-temperature optical gain from AlGaN/AlN multiple quantum wells with strong band-structure potential fluctuations,” Appl. Phys. Lett.100(6), 061111 (2012).
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G. Liu, J. Zhang, X. H. Li, G. S. Huang, T. Paskova, K. R. Evans, H. Zhao, and N. Tansu, “Metalorganic vapor phase epitaxy and characterizations of nearly-lattice-matched AlInN alloys on GaN/sapphire templates and free-standing GaN substrates,” J. Cryst. Growth340(1), 66–73 (2012).
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J. Zhang, H. Zhao, and N. Tansu, “Large optical gain AlGaN-delta-GaN quantum wells laser active regions in mid- and deep-ultraviolet spectral regimes,” Appl. Phys. Lett.98(17), 171111 (2011).
[CrossRef]

J. Zhang, H. Zhao, and N. Tansu, “Effect of crystal-field split-off hole and heavy-hole bands crossover on gain characteristics of high Al-content AlGaN quantum well lasers,” Appl. Phys. Lett.97(11), 111105 (2010).
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H. P. Zhao, G. Y. Liu, J. Zhang, J. D. Poplawsky, V. Dierolf, and N. Tansu, “Approaches for high internal quantum efficiency green InGaN light-emitting diodes with large overlap quantum wells,” Opt. Express19(S4Suppl 4), A991–A1007 (2011).
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H. P. Zhao, G. Y. Liu, X. H. Li, R. A. Arif, G. S. Huang, J. D. Poplawsky, S. Tafon Penn, V. Dierolf, and N. Tansu, “Design and characteristics of staggered InGaN quantum well light-emitting diodes in the green spectral regimes,” IET Optoelectron.3(6), 283–295 (2009).
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Zhao, X.

H. Long, G. Fang, S. Li, X. Mo, H. Wang, H. Huang, Q. Jiang, J. Wang, and X. Zhao, “A ZnO/ZnMgO multiple-quantum-well ultraviolet random laser diode,” IEEE Electron Device Lett.32(1), 54–56 (2011).
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Y. Chen, F. Jiang, L. Wang, C. Zheng, J. Dai, Y. Pu, and W. Fang, “Structural and luminescent properties of ZnO epitaxial film grown on Si(111) substrate by atmospheric-pressure MOCVD,” J. Cryst. Growth275(3-4), 486–491 (2005).
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E. Francesco Pecora, W. Zhang, A. Yu. Nikiforov, L. Zhou, D. J. Smith, J. Yin, R. Paiella, L. Dal Negro, and T. D. Moustakas, “Sub-250 nm room-temperature optical gain from AlGaN/AlN multiple quantum wells with strong band-structure potential fluctuations,” Appl. Phys. Lett.100(6), 061111 (2012).
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X. Q. Gu, L. P. Zhu, Z. Z. Ye, H. P. He, Y. Z. Zhang, F. Huang, M. X. Qiu, Y. J. Zeng, F. Liu, and W. Jaeger, “Room-temperature photoluminescence from ZnO/ZnMgO multiple quantum wells grown on Si(111) substrates,” Appl. Phys. Lett.91(2), 022103 (2007).
[CrossRef]

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D. M. Bagnall, Y. F. Chen, Z. Zhu, T. Yao, S. Koyama, M. Y. Shen, and T. Goto, “Optically pumped lasing of ZnO at room temperature,” Appl. Phys. Lett.70(17), 2230–2232 (1997).
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J. H. Lim, C. K. Kang, K. K. Kim, I. K. Park, D. K. Hwang, and S. J. Park, “UV electroluminescence emission from ZnO light-emitting diodes grown by high-temperature radiofrequency sputtering,” Adv. Mater. 18(20), 2720–2724 (2006).
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Appl. Phys. Lett. (23)

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Figures (8)

Fig. 1
Fig. 1

Schematic picture for the layer structures of (a) Sample A, (b) Sample B, (c) Sample C, and (d) Sample D, used in this work.

Fig. 2
Fig. 2

(a) XRD ω-2θ spectra, and (b) normalized XRC results of Samples A, B, C, and D.

Fig. 3
Fig. 3

Band diagram of (a) Sample A, and (b) Sample B.

Fig. 4
Fig. 4

PL spectra of samples at 10 K.

Fig. 5
Fig. 5

PL spectra as a function of temperatures of (a) Sample A, (b) Sample B, and (c) Sample C.

Fig. 6
Fig. 6

PL spectra of Sample B, deconvoluted with Gaussian functions at 10 and 75K.

Fig. 7
Fig. 7

The normalized integrated intensity of samples as functions of temperature.

Fig. 8
Fig. 8

(a) HRTEM image of Sample C, (b) Enlarged image of blue dashed line area in (a), and (c) Enlarged image of red dashed line area in (a).

Tables (1)

Tables Icon

Table 1 Peak Position, FWHM, Strain, Stress, Lattice Constant, EDS Mg/Zn Ratio, and Mg Concentrations of the Samples from XRD Measurements

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