Abstract

The exciton localization in wurtzite AlxGa1-xN alloys with x varying from 0.41 to 0.63 has been studied by deep-ultraviolet photoluminescence (PL) spectroscopy and picosecond time-resolved PL spectroscopy. Obvious S-shape temperature dependence was observed indicating that the strong exciton localization can be formed in high Al composition AlxGa1-xN alloys. It was also found that the Al composition dependence of exciton localization energy of AlGaN alloys is inconsistent with that of the excitonic linewidth. We contribute the inconsistency to the strong zero-dimensional exciton localization.

© 2013 Optical Society of America

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  1. A. Khan, K. Balakrishnan, and T. Katona, “Ultraviolet light-emitting diodes based on group three nitrides,” Nat. Photonics2(2), 77–84 (2008).
    [CrossRef]
  2. H. Hirayama, S. Fujikawa, N. Noguchi, J. Norimatsu, T. Takano, K. Tsubaki, and N. Kamata, “222-282 nm AlGaN and InAlGaN-based deep-UV LEDs fabricated on high-quality AlN on sapphire,” Phys. Status Solidi206(6), 1176–1182 (2009) (a).
    [CrossRef]
  3. M. S. Shur and R. Gaska, “Deep-ultraviolet light-emitting diodes,” Electron Devices, IEEE Transactions on57(1), 12–25 (2010).
    [CrossRef]
  4. Y. Taniyasu, M. Kasu, and T. Makimoto, “An aluminium nitride light-emitting diode with a wavelength of 210 nanometres,” Nature441(7091), 325–328 (2006).
    [CrossRef] [PubMed]
  5. C. G. Van de Walle and J. Neugebauer, “First-principles calculations for defects and impurities: Applications to III-nitrides,” J. Appl. Phys.95(8), 3851–3879 (2004).
    [CrossRef]
  6. K. Nam, J. Li, M. Nakarmi, J. Lin, and H. Jiang, “Unique optical properties of AlGaN alloys and related ultraviolet emitters,” Appl. Phys. Lett.84(25), 5264–5266 (2004).
    [CrossRef]
  7. R. Banal, M. Funato, and Y. Kawakami, “Optical anisotropy in [0001]-oriented AlxGa1-xN/AlN quantum wells (x> 0.69),” Phys. Rev. B79(12), 121308 (2009).
    [CrossRef]
  8. K. Takeda, F. Mori, Y. Ogiso, T. Ichikawa, K. Nonaka, M. Iwaya, S. Kamiyama, H. Amano, and I. Akasaki, “Internal quantum efficiency of GaN/AlGaN‐based multi quantum wells on different dislocation densities underlying layers,” Phys. Status Solidi7(7-8c), 1916–1918 (2010).
    [CrossRef]
  9. K. O'Donnell, R. Martin, and P. Middleton, “Origin of luminescence from InGaN diodes,” Phys. Rev. Lett.82(1), 237–240 (1999).
    [CrossRef]
  10. H. Yang, P. Kuo, T. Lin, Y. Chen, K. Chen, L. Chen, and J.-I. Chyi, “Mechanism of luminescence in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.76(25), 3712–3714 (2000).
    [CrossRef]
  11. R. Martin, P. Middleton, K. P. O’Donnell, and W. Van der Stricht, “Exciton localization and the Stokes’ shift in InGaN epilayers,” Appl. Phys. Lett.74(2), 263–265 (1999).
    [CrossRef]
  12. Y.-S. Lin, K.-J. Ma, C. Hsu, S.-W. Feng, Y.-C. Cheng, C.-C. Liao, C. Yang, C.-C. Chou, C.-M. Lee, and J.-I. Chyi, “Dependence of composition fluctuation on indium content in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.77(19), 2988–2990 (2000).
    [CrossRef]
  13. Y.-H. Cho, G. Gainer, A. Fischer, J. Song, S. Keller, U. Mishra, and S. DenBaars, ““S-shaped” temperature-dependent emission shift and carrier dynamics in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.73(10), 1370–1372 (1998).
    [CrossRef]
  14. C.-C. Hong, H. Ahn, C.-Y. Wu, and S. Gwo, “Strong green photoluminescence from InxGa1-xN/GaN nanorod arrays,” Opt. Express17(20), 17227–17233 (2009).
    [CrossRef] [PubMed]
  15. N. Nepal, J. Li, M. Nakarmi, J. Lin, and H. Jiang, “Exciton localization in AlGaN alloys,” Appl. Phys. Lett.88(6), 062103 (2006).
    [CrossRef]
  16. E. Kuokstis, W. Sun, M. Shatalov, J. Yang, and M. Asif Khan, “Role of alloy fluctuations in photoluminescence dynamics of AlGaN epilayers,” Appl. Phys. Lett.88(26), 261905 (2006).
    [CrossRef]
  17. A. Bell, S. Srinivasan, C. Plumlee, H. Omiya, F. Ponce, J. Christen, S. Tanaka, A. Fujioka, and Y. Nakagawa, “Exciton freeze-out and thermally activated relaxation at local potential fluctuations in thick AlxGa1-xN layers,” J. Appl. Phys.95(9), 4670–4674 (2004).
    [CrossRef]
  18. H. Kim, R. Mair, J. Li, J. Lin, and H. Jiang, “Time-resolved photoluminescence studies ofAlxGa1-xNalloys,” Appl. Phys. Lett.76(10), 1252–1254 (2000).
    [CrossRef]
  19. T. Onuma, S. F. Chichibu, A. Uedono, T. Sota, P. Cantu, T. M. Katona, J. F. Keading, S. Keller, U. K. Mishra, and S. Nakamura, “Radiative and nonradiative processes in strain-free AlGaN films studied by time-resolved photoluminescence and positron annihilation techniques,” J. Appl. Phys.95(5), 2495 (2004).
    [CrossRef]
  20. H. Gotoh, H. Ando, T. Takagahara, H. Kamada, A. Chavez-Pirson, and J. Temmyo, “Effects of dimensionality on radiative recombination lifetime of excitons in thin quantum boxes of intermediate regime between zero and two Dimensions,” Jpn. J. Appl. Phys.36(Part 1, No. 6B), 4204–4208 (1997).
    [CrossRef]
  21. J. Huang, X. Dong, X. Luo, X. Liu, Z. Xu, and W. Ge, “Localized exciton dynamics in AlInGaN alloy,” Solid State Commun.126(8), 473–477 (2003).
    [CrossRef]
  22. S. Chichibu, K. Hazu, T. Onuma, and A. Uedono, “Collateral evidence for an excellent radiative performance of AlxGa1-xN alloy films of high AlN mole fractions,” Appl. Phys. Lett.99(5), 051902 (2011).
    [CrossRef]
  23. K. Lee, P. Parbrook, T. Wang, F. Ranalli, T. Martin, R. Balmer, and D. Wallis, “Optical investigation of exciton localization in AlxGa1-xN,” J. Appl. Phys.101(5), 053513 (2007).
    [CrossRef]
  24. L. Teles, J. Furthmüller, L. Scolfaro, J. Leite, and F. Bechstedt, “First-principles calculations of the thermodynamic and structural properties of strained InxGa1-xN and AlxGa1-xN alloys,” Phys. Rev. B62(4), 2475–2485 (2000).
    [CrossRef]
  25. M. Miyoshi, M. Sakai, H. Ishikawa, T. Egawa, T. Jimbo, M. Tanaka, and O. Oda, “MOVPE growth and characterization of high-Al-content AlGaN/GaN heterostructures on 100-mm-diameter sapphire substrates,” J. Cryst. Growth272(1-4), 293–299 (2004).
    [CrossRef]
  26. Y. Liao, C. Thomidis, C.- Kao, and T. D. Moustakas, “AlGaN based deep ultraviolet light emitting diodes with high internal quantum efficiency grown by molecular beam epitaxy,” Appl. Phys. Lett.98(8), 081110 (2011).
    [CrossRef]
  27. E. Francesco Pecora, W. Zhang, L. Zhou, D. J. Smith, J. Yin, R. Paiella, L. Dal Negro, and T. Moustakas, “Sub-250 nm room-temperature optical gain from AlGaN/AlN multiple quantum wells with strong band-structure potential fluctuations,” Appl. Phys. Lett.100, 061111 (2012).
    [CrossRef]

2012 (1)

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

2011 (2)

S. Chichibu, K. Hazu, T. Onuma, and A. Uedono, “Collateral evidence for an excellent radiative performance of AlxGa1-xN alloy films of high AlN mole fractions,” Appl. Phys. Lett.99(5), 051902 (2011).
[CrossRef]

Y. Liao, C. Thomidis, C.- Kao, and T. D. Moustakas, “AlGaN based deep ultraviolet light emitting diodes with high internal quantum efficiency grown by molecular beam epitaxy,” Appl. Phys. Lett.98(8), 081110 (2011).
[CrossRef]

2010 (2)

M. S. Shur and R. Gaska, “Deep-ultraviolet light-emitting diodes,” Electron Devices, IEEE Transactions on57(1), 12–25 (2010).
[CrossRef]

K. Takeda, F. Mori, Y. Ogiso, T. Ichikawa, K. Nonaka, M. Iwaya, S. Kamiyama, H. Amano, and I. Akasaki, “Internal quantum efficiency of GaN/AlGaN‐based multi quantum wells on different dislocation densities underlying layers,” Phys. Status Solidi7(7-8c), 1916–1918 (2010).
[CrossRef]

2009 (3)

H. Hirayama, S. Fujikawa, N. Noguchi, J. Norimatsu, T. Takano, K. Tsubaki, and N. Kamata, “222-282 nm AlGaN and InAlGaN-based deep-UV LEDs fabricated on high-quality AlN on sapphire,” Phys. Status Solidi206(6), 1176–1182 (2009) (a).
[CrossRef]

R. Banal, M. Funato, and Y. Kawakami, “Optical anisotropy in [0001]-oriented AlxGa1-xN/AlN quantum wells (x> 0.69),” Phys. Rev. B79(12), 121308 (2009).
[CrossRef]

C.-C. Hong, H. Ahn, C.-Y. Wu, and S. Gwo, “Strong green photoluminescence from InxGa1-xN/GaN nanorod arrays,” Opt. Express17(20), 17227–17233 (2009).
[CrossRef] [PubMed]

2008 (1)

A. Khan, K. Balakrishnan, and T. Katona, “Ultraviolet light-emitting diodes based on group three nitrides,” Nat. Photonics2(2), 77–84 (2008).
[CrossRef]

2007 (1)

K. Lee, P. Parbrook, T. Wang, F. Ranalli, T. Martin, R. Balmer, and D. Wallis, “Optical investigation of exciton localization in AlxGa1-xN,” J. Appl. Phys.101(5), 053513 (2007).
[CrossRef]

2006 (3)

Y. Taniyasu, M. Kasu, and T. Makimoto, “An aluminium nitride light-emitting diode with a wavelength of 210 nanometres,” Nature441(7091), 325–328 (2006).
[CrossRef] [PubMed]

N. Nepal, J. Li, M. Nakarmi, J. Lin, and H. Jiang, “Exciton localization in AlGaN alloys,” Appl. Phys. Lett.88(6), 062103 (2006).
[CrossRef]

E. Kuokstis, W. Sun, M. Shatalov, J. Yang, and M. Asif Khan, “Role of alloy fluctuations in photoluminescence dynamics of AlGaN epilayers,” Appl. Phys. Lett.88(26), 261905 (2006).
[CrossRef]

2004 (5)

A. Bell, S. Srinivasan, C. Plumlee, H. Omiya, F. Ponce, J. Christen, S. Tanaka, A. Fujioka, and Y. Nakagawa, “Exciton freeze-out and thermally activated relaxation at local potential fluctuations in thick AlxGa1-xN layers,” J. Appl. Phys.95(9), 4670–4674 (2004).
[CrossRef]

C. G. Van de Walle and J. Neugebauer, “First-principles calculations for defects and impurities: Applications to III-nitrides,” J. Appl. Phys.95(8), 3851–3879 (2004).
[CrossRef]

K. Nam, J. Li, M. Nakarmi, J. Lin, and H. Jiang, “Unique optical properties of AlGaN alloys and related ultraviolet emitters,” Appl. Phys. Lett.84(25), 5264–5266 (2004).
[CrossRef]

M. Miyoshi, M. Sakai, H. Ishikawa, T. Egawa, T. Jimbo, M. Tanaka, and O. Oda, “MOVPE growth and characterization of high-Al-content AlGaN/GaN heterostructures on 100-mm-diameter sapphire substrates,” J. Cryst. Growth272(1-4), 293–299 (2004).
[CrossRef]

T. Onuma, S. F. Chichibu, A. Uedono, T. Sota, P. Cantu, T. M. Katona, J. F. Keading, S. Keller, U. K. Mishra, and S. Nakamura, “Radiative and nonradiative processes in strain-free AlGaN films studied by time-resolved photoluminescence and positron annihilation techniques,” J. Appl. Phys.95(5), 2495 (2004).
[CrossRef]

2003 (1)

J. Huang, X. Dong, X. Luo, X. Liu, Z. Xu, and W. Ge, “Localized exciton dynamics in AlInGaN alloy,” Solid State Commun.126(8), 473–477 (2003).
[CrossRef]

2000 (4)

L. Teles, J. Furthmüller, L. Scolfaro, J. Leite, and F. Bechstedt, “First-principles calculations of the thermodynamic and structural properties of strained InxGa1-xN and AlxGa1-xN alloys,” Phys. Rev. B62(4), 2475–2485 (2000).
[CrossRef]

H. Kim, R. Mair, J. Li, J. Lin, and H. Jiang, “Time-resolved photoluminescence studies ofAlxGa1-xNalloys,” Appl. Phys. Lett.76(10), 1252–1254 (2000).
[CrossRef]

H. Yang, P. Kuo, T. Lin, Y. Chen, K. Chen, L. Chen, and J.-I. Chyi, “Mechanism of luminescence in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.76(25), 3712–3714 (2000).
[CrossRef]

Y.-S. Lin, K.-J. Ma, C. Hsu, S.-W. Feng, Y.-C. Cheng, C.-C. Liao, C. Yang, C.-C. Chou, C.-M. Lee, and J.-I. Chyi, “Dependence of composition fluctuation on indium content in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.77(19), 2988–2990 (2000).
[CrossRef]

1999 (2)

R. Martin, P. Middleton, K. P. O’Donnell, and W. Van der Stricht, “Exciton localization and the Stokes’ shift in InGaN epilayers,” Appl. Phys. Lett.74(2), 263–265 (1999).
[CrossRef]

K. O'Donnell, R. Martin, and P. Middleton, “Origin of luminescence from InGaN diodes,” Phys. Rev. Lett.82(1), 237–240 (1999).
[CrossRef]

1998 (1)

Y.-H. Cho, G. Gainer, A. Fischer, J. Song, S. Keller, U. Mishra, and S. DenBaars, ““S-shaped” temperature-dependent emission shift and carrier dynamics in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.73(10), 1370–1372 (1998).
[CrossRef]

1997 (1)

H. Gotoh, H. Ando, T. Takagahara, H. Kamada, A. Chavez-Pirson, and J. Temmyo, “Effects of dimensionality on radiative recombination lifetime of excitons in thin quantum boxes of intermediate regime between zero and two Dimensions,” Jpn. J. Appl. Phys.36(Part 1, No. 6B), 4204–4208 (1997).
[CrossRef]

Ahn, H.

Akasaki, I.

K. Takeda, F. Mori, Y. Ogiso, T. Ichikawa, K. Nonaka, M. Iwaya, S. Kamiyama, H. Amano, and I. Akasaki, “Internal quantum efficiency of GaN/AlGaN‐based multi quantum wells on different dislocation densities underlying layers,” Phys. Status Solidi7(7-8c), 1916–1918 (2010).
[CrossRef]

Amano, H.

K. Takeda, F. Mori, Y. Ogiso, T. Ichikawa, K. Nonaka, M. Iwaya, S. Kamiyama, H. Amano, and I. Akasaki, “Internal quantum efficiency of GaN/AlGaN‐based multi quantum wells on different dislocation densities underlying layers,” Phys. Status Solidi7(7-8c), 1916–1918 (2010).
[CrossRef]

Ando, H.

H. Gotoh, H. Ando, T. Takagahara, H. Kamada, A. Chavez-Pirson, and J. Temmyo, “Effects of dimensionality on radiative recombination lifetime of excitons in thin quantum boxes of intermediate regime between zero and two Dimensions,” Jpn. J. Appl. Phys.36(Part 1, No. 6B), 4204–4208 (1997).
[CrossRef]

Asif Khan, M.

E. Kuokstis, W. Sun, M. Shatalov, J. Yang, and M. Asif Khan, “Role of alloy fluctuations in photoluminescence dynamics of AlGaN epilayers,” Appl. Phys. Lett.88(26), 261905 (2006).
[CrossRef]

Balakrishnan, K.

A. Khan, K. Balakrishnan, and T. Katona, “Ultraviolet light-emitting diodes based on group three nitrides,” Nat. Photonics2(2), 77–84 (2008).
[CrossRef]

Balmer, R.

K. Lee, P. Parbrook, T. Wang, F. Ranalli, T. Martin, R. Balmer, and D. Wallis, “Optical investigation of exciton localization in AlxGa1-xN,” J. Appl. Phys.101(5), 053513 (2007).
[CrossRef]

Banal, R.

R. Banal, M. Funato, and Y. Kawakami, “Optical anisotropy in [0001]-oriented AlxGa1-xN/AlN quantum wells (x> 0.69),” Phys. Rev. B79(12), 121308 (2009).
[CrossRef]

Bechstedt, F.

L. Teles, J. Furthmüller, L. Scolfaro, J. Leite, and F. Bechstedt, “First-principles calculations of the thermodynamic and structural properties of strained InxGa1-xN and AlxGa1-xN alloys,” Phys. Rev. B62(4), 2475–2485 (2000).
[CrossRef]

Bell, A.

A. Bell, S. Srinivasan, C. Plumlee, H. Omiya, F. Ponce, J. Christen, S. Tanaka, A. Fujioka, and Y. Nakagawa, “Exciton freeze-out and thermally activated relaxation at local potential fluctuations in thick AlxGa1-xN layers,” J. Appl. Phys.95(9), 4670–4674 (2004).
[CrossRef]

Cantu, P.

T. Onuma, S. F. Chichibu, A. Uedono, T. Sota, P. Cantu, T. M. Katona, J. F. Keading, S. Keller, U. K. Mishra, and S. Nakamura, “Radiative and nonradiative processes in strain-free AlGaN films studied by time-resolved photoluminescence and positron annihilation techniques,” J. Appl. Phys.95(5), 2495 (2004).
[CrossRef]

Chavez-Pirson, A.

H. Gotoh, H. Ando, T. Takagahara, H. Kamada, A. Chavez-Pirson, and J. Temmyo, “Effects of dimensionality on radiative recombination lifetime of excitons in thin quantum boxes of intermediate regime between zero and two Dimensions,” Jpn. J. Appl. Phys.36(Part 1, No. 6B), 4204–4208 (1997).
[CrossRef]

Chen, K.

H. Yang, P. Kuo, T. Lin, Y. Chen, K. Chen, L. Chen, and J.-I. Chyi, “Mechanism of luminescence in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.76(25), 3712–3714 (2000).
[CrossRef]

Chen, L.

H. Yang, P. Kuo, T. Lin, Y. Chen, K. Chen, L. Chen, and J.-I. Chyi, “Mechanism of luminescence in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.76(25), 3712–3714 (2000).
[CrossRef]

Chen, Y.

H. Yang, P. Kuo, T. Lin, Y. Chen, K. Chen, L. Chen, and J.-I. Chyi, “Mechanism of luminescence in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.76(25), 3712–3714 (2000).
[CrossRef]

Cheng, Y.-C.

Y.-S. Lin, K.-J. Ma, C. Hsu, S.-W. Feng, Y.-C. Cheng, C.-C. Liao, C. Yang, C.-C. Chou, C.-M. Lee, and J.-I. Chyi, “Dependence of composition fluctuation on indium content in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.77(19), 2988–2990 (2000).
[CrossRef]

Chichibu, S.

S. Chichibu, K. Hazu, T. Onuma, and A. Uedono, “Collateral evidence for an excellent radiative performance of AlxGa1-xN alloy films of high AlN mole fractions,” Appl. Phys. Lett.99(5), 051902 (2011).
[CrossRef]

Chichibu, S. F.

T. Onuma, S. F. Chichibu, A. Uedono, T. Sota, P. Cantu, T. M. Katona, J. F. Keading, S. Keller, U. K. Mishra, and S. Nakamura, “Radiative and nonradiative processes in strain-free AlGaN films studied by time-resolved photoluminescence and positron annihilation techniques,” J. Appl. Phys.95(5), 2495 (2004).
[CrossRef]

Cho, Y.-H.

Y.-H. Cho, G. Gainer, A. Fischer, J. Song, S. Keller, U. Mishra, and S. DenBaars, ““S-shaped” temperature-dependent emission shift and carrier dynamics in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.73(10), 1370–1372 (1998).
[CrossRef]

Chou, C.-C.

Y.-S. Lin, K.-J. Ma, C. Hsu, S.-W. Feng, Y.-C. Cheng, C.-C. Liao, C. Yang, C.-C. Chou, C.-M. Lee, and J.-I. Chyi, “Dependence of composition fluctuation on indium content in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.77(19), 2988–2990 (2000).
[CrossRef]

Christen, J.

A. Bell, S. Srinivasan, C. Plumlee, H. Omiya, F. Ponce, J. Christen, S. Tanaka, A. Fujioka, and Y. Nakagawa, “Exciton freeze-out and thermally activated relaxation at local potential fluctuations in thick AlxGa1-xN layers,” J. Appl. Phys.95(9), 4670–4674 (2004).
[CrossRef]

Chyi, J.-I.

Y.-S. Lin, K.-J. Ma, C. Hsu, S.-W. Feng, Y.-C. Cheng, C.-C. Liao, C. Yang, C.-C. Chou, C.-M. Lee, and J.-I. Chyi, “Dependence of composition fluctuation on indium content in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.77(19), 2988–2990 (2000).
[CrossRef]

H. Yang, P. Kuo, T. Lin, Y. Chen, K. Chen, L. Chen, and J.-I. Chyi, “Mechanism of luminescence in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.76(25), 3712–3714 (2000).
[CrossRef]

Dal Negro, L.

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

DenBaars, S.

Y.-H. Cho, G. Gainer, A. Fischer, J. Song, S. Keller, U. Mishra, and S. DenBaars, ““S-shaped” temperature-dependent emission shift and carrier dynamics in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.73(10), 1370–1372 (1998).
[CrossRef]

Dong, X.

J. Huang, X. Dong, X. Luo, X. Liu, Z. Xu, and W. Ge, “Localized exciton dynamics in AlInGaN alloy,” Solid State Commun.126(8), 473–477 (2003).
[CrossRef]

Egawa, T.

M. Miyoshi, M. Sakai, H. Ishikawa, T. Egawa, T. Jimbo, M. Tanaka, and O. Oda, “MOVPE growth and characterization of high-Al-content AlGaN/GaN heterostructures on 100-mm-diameter sapphire substrates,” J. Cryst. Growth272(1-4), 293–299 (2004).
[CrossRef]

Feng, S.-W.

Y.-S. Lin, K.-J. Ma, C. Hsu, S.-W. Feng, Y.-C. Cheng, C.-C. Liao, C. Yang, C.-C. Chou, C.-M. Lee, and J.-I. Chyi, “Dependence of composition fluctuation on indium content in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.77(19), 2988–2990 (2000).
[CrossRef]

Fischer, A.

Y.-H. Cho, G. Gainer, A. Fischer, J. Song, S. Keller, U. Mishra, and S. DenBaars, ““S-shaped” temperature-dependent emission shift and carrier dynamics in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.73(10), 1370–1372 (1998).
[CrossRef]

Francesco Pecora, E.

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

Fujikawa, S.

H. Hirayama, S. Fujikawa, N. Noguchi, J. Norimatsu, T. Takano, K. Tsubaki, and N. Kamata, “222-282 nm AlGaN and InAlGaN-based deep-UV LEDs fabricated on high-quality AlN on sapphire,” Phys. Status Solidi206(6), 1176–1182 (2009) (a).
[CrossRef]

Fujioka, A.

A. Bell, S. Srinivasan, C. Plumlee, H. Omiya, F. Ponce, J. Christen, S. Tanaka, A. Fujioka, and Y. Nakagawa, “Exciton freeze-out and thermally activated relaxation at local potential fluctuations in thick AlxGa1-xN layers,” J. Appl. Phys.95(9), 4670–4674 (2004).
[CrossRef]

Funato, M.

R. Banal, M. Funato, and Y. Kawakami, “Optical anisotropy in [0001]-oriented AlxGa1-xN/AlN quantum wells (x> 0.69),” Phys. Rev. B79(12), 121308 (2009).
[CrossRef]

Furthmüller, J.

L. Teles, J. Furthmüller, L. Scolfaro, J. Leite, and F. Bechstedt, “First-principles calculations of the thermodynamic and structural properties of strained InxGa1-xN and AlxGa1-xN alloys,” Phys. Rev. B62(4), 2475–2485 (2000).
[CrossRef]

Gainer, G.

Y.-H. Cho, G. Gainer, A. Fischer, J. Song, S. Keller, U. Mishra, and S. DenBaars, ““S-shaped” temperature-dependent emission shift and carrier dynamics in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.73(10), 1370–1372 (1998).
[CrossRef]

Gaska, R.

M. S. Shur and R. Gaska, “Deep-ultraviolet light-emitting diodes,” Electron Devices, IEEE Transactions on57(1), 12–25 (2010).
[CrossRef]

Ge, W.

J. Huang, X. Dong, X. Luo, X. Liu, Z. Xu, and W. Ge, “Localized exciton dynamics in AlInGaN alloy,” Solid State Commun.126(8), 473–477 (2003).
[CrossRef]

Gotoh, H.

H. Gotoh, H. Ando, T. Takagahara, H. Kamada, A. Chavez-Pirson, and J. Temmyo, “Effects of dimensionality on radiative recombination lifetime of excitons in thin quantum boxes of intermediate regime between zero and two Dimensions,” Jpn. J. Appl. Phys.36(Part 1, No. 6B), 4204–4208 (1997).
[CrossRef]

Gwo, S.

Hazu, K.

S. Chichibu, K. Hazu, T. Onuma, and A. Uedono, “Collateral evidence for an excellent radiative performance of AlxGa1-xN alloy films of high AlN mole fractions,” Appl. Phys. Lett.99(5), 051902 (2011).
[CrossRef]

Hirayama, H.

H. Hirayama, S. Fujikawa, N. Noguchi, J. Norimatsu, T. Takano, K. Tsubaki, and N. Kamata, “222-282 nm AlGaN and InAlGaN-based deep-UV LEDs fabricated on high-quality AlN on sapphire,” Phys. Status Solidi206(6), 1176–1182 (2009) (a).
[CrossRef]

Hong, C.-C.

Hsu, C.

Y.-S. Lin, K.-J. Ma, C. Hsu, S.-W. Feng, Y.-C. Cheng, C.-C. Liao, C. Yang, C.-C. Chou, C.-M. Lee, and J.-I. Chyi, “Dependence of composition fluctuation on indium content in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.77(19), 2988–2990 (2000).
[CrossRef]

Huang, J.

J. Huang, X. Dong, X. Luo, X. Liu, Z. Xu, and W. Ge, “Localized exciton dynamics in AlInGaN alloy,” Solid State Commun.126(8), 473–477 (2003).
[CrossRef]

Ichikawa, T.

K. Takeda, F. Mori, Y. Ogiso, T. Ichikawa, K. Nonaka, M. Iwaya, S. Kamiyama, H. Amano, and I. Akasaki, “Internal quantum efficiency of GaN/AlGaN‐based multi quantum wells on different dislocation densities underlying layers,” Phys. Status Solidi7(7-8c), 1916–1918 (2010).
[CrossRef]

Ishikawa, H.

M. Miyoshi, M. Sakai, H. Ishikawa, T. Egawa, T. Jimbo, M. Tanaka, and O. Oda, “MOVPE growth and characterization of high-Al-content AlGaN/GaN heterostructures on 100-mm-diameter sapphire substrates,” J. Cryst. Growth272(1-4), 293–299 (2004).
[CrossRef]

Iwaya, M.

K. Takeda, F. Mori, Y. Ogiso, T. Ichikawa, K. Nonaka, M. Iwaya, S. Kamiyama, H. Amano, and I. Akasaki, “Internal quantum efficiency of GaN/AlGaN‐based multi quantum wells on different dislocation densities underlying layers,” Phys. Status Solidi7(7-8c), 1916–1918 (2010).
[CrossRef]

Jiang, H.

N. Nepal, J. Li, M. Nakarmi, J. Lin, and H. Jiang, “Exciton localization in AlGaN alloys,” Appl. Phys. Lett.88(6), 062103 (2006).
[CrossRef]

K. Nam, J. Li, M. Nakarmi, J. Lin, and H. Jiang, “Unique optical properties of AlGaN alloys and related ultraviolet emitters,” Appl. Phys. Lett.84(25), 5264–5266 (2004).
[CrossRef]

H. Kim, R. Mair, J. Li, J. Lin, and H. Jiang, “Time-resolved photoluminescence studies ofAlxGa1-xNalloys,” Appl. Phys. Lett.76(10), 1252–1254 (2000).
[CrossRef]

Jimbo, T.

M. Miyoshi, M. Sakai, H. Ishikawa, T. Egawa, T. Jimbo, M. Tanaka, and O. Oda, “MOVPE growth and characterization of high-Al-content AlGaN/GaN heterostructures on 100-mm-diameter sapphire substrates,” J. Cryst. Growth272(1-4), 293–299 (2004).
[CrossRef]

Kamada, H.

H. Gotoh, H. Ando, T. Takagahara, H. Kamada, A. Chavez-Pirson, and J. Temmyo, “Effects of dimensionality on radiative recombination lifetime of excitons in thin quantum boxes of intermediate regime between zero and two Dimensions,” Jpn. J. Appl. Phys.36(Part 1, No. 6B), 4204–4208 (1997).
[CrossRef]

Kamata, N.

H. Hirayama, S. Fujikawa, N. Noguchi, J. Norimatsu, T. Takano, K. Tsubaki, and N. Kamata, “222-282 nm AlGaN and InAlGaN-based deep-UV LEDs fabricated on high-quality AlN on sapphire,” Phys. Status Solidi206(6), 1176–1182 (2009) (a).
[CrossRef]

Kamiyama, S.

K. Takeda, F. Mori, Y. Ogiso, T. Ichikawa, K. Nonaka, M. Iwaya, S. Kamiyama, H. Amano, and I. Akasaki, “Internal quantum efficiency of GaN/AlGaN‐based multi quantum wells on different dislocation densities underlying layers,” Phys. Status Solidi7(7-8c), 1916–1918 (2010).
[CrossRef]

Kao, C.-

Y. Liao, C. Thomidis, C.- Kao, and T. D. Moustakas, “AlGaN based deep ultraviolet light emitting diodes with high internal quantum efficiency grown by molecular beam epitaxy,” Appl. Phys. Lett.98(8), 081110 (2011).
[CrossRef]

Kasu, M.

Y. Taniyasu, M. Kasu, and T. Makimoto, “An aluminium nitride light-emitting diode with a wavelength of 210 nanometres,” Nature441(7091), 325–328 (2006).
[CrossRef] [PubMed]

Katona, T.

A. Khan, K. Balakrishnan, and T. Katona, “Ultraviolet light-emitting diodes based on group three nitrides,” Nat. Photonics2(2), 77–84 (2008).
[CrossRef]

Katona, T. M.

T. Onuma, S. F. Chichibu, A. Uedono, T. Sota, P. Cantu, T. M. Katona, J. F. Keading, S. Keller, U. K. Mishra, and S. Nakamura, “Radiative and nonradiative processes in strain-free AlGaN films studied by time-resolved photoluminescence and positron annihilation techniques,” J. Appl. Phys.95(5), 2495 (2004).
[CrossRef]

Kawakami, Y.

R. Banal, M. Funato, and Y. Kawakami, “Optical anisotropy in [0001]-oriented AlxGa1-xN/AlN quantum wells (x> 0.69),” Phys. Rev. B79(12), 121308 (2009).
[CrossRef]

Keading, J. F.

T. Onuma, S. F. Chichibu, A. Uedono, T. Sota, P. Cantu, T. M. Katona, J. F. Keading, S. Keller, U. K. Mishra, and S. Nakamura, “Radiative and nonradiative processes in strain-free AlGaN films studied by time-resolved photoluminescence and positron annihilation techniques,” J. Appl. Phys.95(5), 2495 (2004).
[CrossRef]

Keller, S.

T. Onuma, S. F. Chichibu, A. Uedono, T. Sota, P. Cantu, T. M. Katona, J. F. Keading, S. Keller, U. K. Mishra, and S. Nakamura, “Radiative and nonradiative processes in strain-free AlGaN films studied by time-resolved photoluminescence and positron annihilation techniques,” J. Appl. Phys.95(5), 2495 (2004).
[CrossRef]

Y.-H. Cho, G. Gainer, A. Fischer, J. Song, S. Keller, U. Mishra, and S. DenBaars, ““S-shaped” temperature-dependent emission shift and carrier dynamics in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.73(10), 1370–1372 (1998).
[CrossRef]

Khan, A.

A. Khan, K. Balakrishnan, and T. Katona, “Ultraviolet light-emitting diodes based on group three nitrides,” Nat. Photonics2(2), 77–84 (2008).
[CrossRef]

Kim, H.

H. Kim, R. Mair, J. Li, J. Lin, and H. Jiang, “Time-resolved photoluminescence studies ofAlxGa1-xNalloys,” Appl. Phys. Lett.76(10), 1252–1254 (2000).
[CrossRef]

Kuo, P.

H. Yang, P. Kuo, T. Lin, Y. Chen, K. Chen, L. Chen, and J.-I. Chyi, “Mechanism of luminescence in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.76(25), 3712–3714 (2000).
[CrossRef]

Kuokstis, E.

E. Kuokstis, W. Sun, M. Shatalov, J. Yang, and M. Asif Khan, “Role of alloy fluctuations in photoluminescence dynamics of AlGaN epilayers,” Appl. Phys. Lett.88(26), 261905 (2006).
[CrossRef]

Lee, C.-M.

Y.-S. Lin, K.-J. Ma, C. Hsu, S.-W. Feng, Y.-C. Cheng, C.-C. Liao, C. Yang, C.-C. Chou, C.-M. Lee, and J.-I. Chyi, “Dependence of composition fluctuation on indium content in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.77(19), 2988–2990 (2000).
[CrossRef]

Lee, K.

K. Lee, P. Parbrook, T. Wang, F. Ranalli, T. Martin, R. Balmer, and D. Wallis, “Optical investigation of exciton localization in AlxGa1-xN,” J. Appl. Phys.101(5), 053513 (2007).
[CrossRef]

Leite, J.

L. Teles, J. Furthmüller, L. Scolfaro, J. Leite, and F. Bechstedt, “First-principles calculations of the thermodynamic and structural properties of strained InxGa1-xN and AlxGa1-xN alloys,” Phys. Rev. B62(4), 2475–2485 (2000).
[CrossRef]

Li, J.

N. Nepal, J. Li, M. Nakarmi, J. Lin, and H. Jiang, “Exciton localization in AlGaN alloys,” Appl. Phys. Lett.88(6), 062103 (2006).
[CrossRef]

K. Nam, J. Li, M. Nakarmi, J. Lin, and H. Jiang, “Unique optical properties of AlGaN alloys and related ultraviolet emitters,” Appl. Phys. Lett.84(25), 5264–5266 (2004).
[CrossRef]

H. Kim, R. Mair, J. Li, J. Lin, and H. Jiang, “Time-resolved photoluminescence studies ofAlxGa1-xNalloys,” Appl. Phys. Lett.76(10), 1252–1254 (2000).
[CrossRef]

Liao, C.-C.

Y.-S. Lin, K.-J. Ma, C. Hsu, S.-W. Feng, Y.-C. Cheng, C.-C. Liao, C. Yang, C.-C. Chou, C.-M. Lee, and J.-I. Chyi, “Dependence of composition fluctuation on indium content in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.77(19), 2988–2990 (2000).
[CrossRef]

Liao, Y.

Y. Liao, C. Thomidis, C.- Kao, and T. D. Moustakas, “AlGaN based deep ultraviolet light emitting diodes with high internal quantum efficiency grown by molecular beam epitaxy,” Appl. Phys. Lett.98(8), 081110 (2011).
[CrossRef]

Lin, J.

N. Nepal, J. Li, M. Nakarmi, J. Lin, and H. Jiang, “Exciton localization in AlGaN alloys,” Appl. Phys. Lett.88(6), 062103 (2006).
[CrossRef]

K. Nam, J. Li, M. Nakarmi, J. Lin, and H. Jiang, “Unique optical properties of AlGaN alloys and related ultraviolet emitters,” Appl. Phys. Lett.84(25), 5264–5266 (2004).
[CrossRef]

H. Kim, R. Mair, J. Li, J. Lin, and H. Jiang, “Time-resolved photoluminescence studies ofAlxGa1-xNalloys,” Appl. Phys. Lett.76(10), 1252–1254 (2000).
[CrossRef]

Lin, T.

H. Yang, P. Kuo, T. Lin, Y. Chen, K. Chen, L. Chen, and J.-I. Chyi, “Mechanism of luminescence in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.76(25), 3712–3714 (2000).
[CrossRef]

Lin, Y.-S.

Y.-S. Lin, K.-J. Ma, C. Hsu, S.-W. Feng, Y.-C. Cheng, C.-C. Liao, C. Yang, C.-C. Chou, C.-M. Lee, and J.-I. Chyi, “Dependence of composition fluctuation on indium content in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.77(19), 2988–2990 (2000).
[CrossRef]

Liu, X.

J. Huang, X. Dong, X. Luo, X. Liu, Z. Xu, and W. Ge, “Localized exciton dynamics in AlInGaN alloy,” Solid State Commun.126(8), 473–477 (2003).
[CrossRef]

Luo, X.

J. Huang, X. Dong, X. Luo, X. Liu, Z. Xu, and W. Ge, “Localized exciton dynamics in AlInGaN alloy,” Solid State Commun.126(8), 473–477 (2003).
[CrossRef]

Ma, K.-J.

Y.-S. Lin, K.-J. Ma, C. Hsu, S.-W. Feng, Y.-C. Cheng, C.-C. Liao, C. Yang, C.-C. Chou, C.-M. Lee, and J.-I. Chyi, “Dependence of composition fluctuation on indium content in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.77(19), 2988–2990 (2000).
[CrossRef]

Mair, R.

H. Kim, R. Mair, J. Li, J. Lin, and H. Jiang, “Time-resolved photoluminescence studies ofAlxGa1-xNalloys,” Appl. Phys. Lett.76(10), 1252–1254 (2000).
[CrossRef]

Makimoto, T.

Y. Taniyasu, M. Kasu, and T. Makimoto, “An aluminium nitride light-emitting diode with a wavelength of 210 nanometres,” Nature441(7091), 325–328 (2006).
[CrossRef] [PubMed]

Martin, R.

K. O'Donnell, R. Martin, and P. Middleton, “Origin of luminescence from InGaN diodes,” Phys. Rev. Lett.82(1), 237–240 (1999).
[CrossRef]

R. Martin, P. Middleton, K. P. O’Donnell, and W. Van der Stricht, “Exciton localization and the Stokes’ shift in InGaN epilayers,” Appl. Phys. Lett.74(2), 263–265 (1999).
[CrossRef]

Martin, T.

K. Lee, P. Parbrook, T. Wang, F. Ranalli, T. Martin, R. Balmer, and D. Wallis, “Optical investigation of exciton localization in AlxGa1-xN,” J. Appl. Phys.101(5), 053513 (2007).
[CrossRef]

Middleton, P.

R. Martin, P. Middleton, K. P. O’Donnell, and W. Van der Stricht, “Exciton localization and the Stokes’ shift in InGaN epilayers,” Appl. Phys. Lett.74(2), 263–265 (1999).
[CrossRef]

K. O'Donnell, R. Martin, and P. Middleton, “Origin of luminescence from InGaN diodes,” Phys. Rev. Lett.82(1), 237–240 (1999).
[CrossRef]

Mishra, U.

Y.-H. Cho, G. Gainer, A. Fischer, J. Song, S. Keller, U. Mishra, and S. DenBaars, ““S-shaped” temperature-dependent emission shift and carrier dynamics in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.73(10), 1370–1372 (1998).
[CrossRef]

Mishra, U. K.

T. Onuma, S. F. Chichibu, A. Uedono, T. Sota, P. Cantu, T. M. Katona, J. F. Keading, S. Keller, U. K. Mishra, and S. Nakamura, “Radiative and nonradiative processes in strain-free AlGaN films studied by time-resolved photoluminescence and positron annihilation techniques,” J. Appl. Phys.95(5), 2495 (2004).
[CrossRef]

Miyoshi, M.

M. Miyoshi, M. Sakai, H. Ishikawa, T. Egawa, T. Jimbo, M. Tanaka, and O. Oda, “MOVPE growth and characterization of high-Al-content AlGaN/GaN heterostructures on 100-mm-diameter sapphire substrates,” J. Cryst. Growth272(1-4), 293–299 (2004).
[CrossRef]

Mori, F.

K. Takeda, F. Mori, Y. Ogiso, T. Ichikawa, K. Nonaka, M. Iwaya, S. Kamiyama, H. Amano, and I. Akasaki, “Internal quantum efficiency of GaN/AlGaN‐based multi quantum wells on different dislocation densities underlying layers,” Phys. Status Solidi7(7-8c), 1916–1918 (2010).
[CrossRef]

Moustakas, T.

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

Moustakas, T. D.

Y. Liao, C. Thomidis, C.- Kao, and T. D. Moustakas, “AlGaN based deep ultraviolet light emitting diodes with high internal quantum efficiency grown by molecular beam epitaxy,” Appl. Phys. Lett.98(8), 081110 (2011).
[CrossRef]

Nakagawa, Y.

A. Bell, S. Srinivasan, C. Plumlee, H. Omiya, F. Ponce, J. Christen, S. Tanaka, A. Fujioka, and Y. Nakagawa, “Exciton freeze-out and thermally activated relaxation at local potential fluctuations in thick AlxGa1-xN layers,” J. Appl. Phys.95(9), 4670–4674 (2004).
[CrossRef]

Nakamura, S.

T. Onuma, S. F. Chichibu, A. Uedono, T. Sota, P. Cantu, T. M. Katona, J. F. Keading, S. Keller, U. K. Mishra, and S. Nakamura, “Radiative and nonradiative processes in strain-free AlGaN films studied by time-resolved photoluminescence and positron annihilation techniques,” J. Appl. Phys.95(5), 2495 (2004).
[CrossRef]

Nakarmi, M.

N. Nepal, J. Li, M. Nakarmi, J. Lin, and H. Jiang, “Exciton localization in AlGaN alloys,” Appl. Phys. Lett.88(6), 062103 (2006).
[CrossRef]

K. Nam, J. Li, M. Nakarmi, J. Lin, and H. Jiang, “Unique optical properties of AlGaN alloys and related ultraviolet emitters,” Appl. Phys. Lett.84(25), 5264–5266 (2004).
[CrossRef]

Nam, K.

K. Nam, J. Li, M. Nakarmi, J. Lin, and H. Jiang, “Unique optical properties of AlGaN alloys and related ultraviolet emitters,” Appl. Phys. Lett.84(25), 5264–5266 (2004).
[CrossRef]

Nepal, N.

N. Nepal, J. Li, M. Nakarmi, J. Lin, and H. Jiang, “Exciton localization in AlGaN alloys,” Appl. Phys. Lett.88(6), 062103 (2006).
[CrossRef]

Neugebauer, J.

C. G. Van de Walle and J. Neugebauer, “First-principles calculations for defects and impurities: Applications to III-nitrides,” J. Appl. Phys.95(8), 3851–3879 (2004).
[CrossRef]

Noguchi, N.

H. Hirayama, S. Fujikawa, N. Noguchi, J. Norimatsu, T. Takano, K. Tsubaki, and N. Kamata, “222-282 nm AlGaN and InAlGaN-based deep-UV LEDs fabricated on high-quality AlN on sapphire,” Phys. Status Solidi206(6), 1176–1182 (2009) (a).
[CrossRef]

Nonaka, K.

K. Takeda, F. Mori, Y. Ogiso, T. Ichikawa, K. Nonaka, M. Iwaya, S. Kamiyama, H. Amano, and I. Akasaki, “Internal quantum efficiency of GaN/AlGaN‐based multi quantum wells on different dislocation densities underlying layers,” Phys. Status Solidi7(7-8c), 1916–1918 (2010).
[CrossRef]

Norimatsu, J.

H. Hirayama, S. Fujikawa, N. Noguchi, J. Norimatsu, T. Takano, K. Tsubaki, and N. Kamata, “222-282 nm AlGaN and InAlGaN-based deep-UV LEDs fabricated on high-quality AlN on sapphire,” Phys. Status Solidi206(6), 1176–1182 (2009) (a).
[CrossRef]

O’Donnell, K. P.

R. Martin, P. Middleton, K. P. O’Donnell, and W. Van der Stricht, “Exciton localization and the Stokes’ shift in InGaN epilayers,” Appl. Phys. Lett.74(2), 263–265 (1999).
[CrossRef]

Oda, O.

M. Miyoshi, M. Sakai, H. Ishikawa, T. Egawa, T. Jimbo, M. Tanaka, and O. Oda, “MOVPE growth and characterization of high-Al-content AlGaN/GaN heterostructures on 100-mm-diameter sapphire substrates,” J. Cryst. Growth272(1-4), 293–299 (2004).
[CrossRef]

O'Donnell, K.

K. O'Donnell, R. Martin, and P. Middleton, “Origin of luminescence from InGaN diodes,” Phys. Rev. Lett.82(1), 237–240 (1999).
[CrossRef]

Ogiso, Y.

K. Takeda, F. Mori, Y. Ogiso, T. Ichikawa, K. Nonaka, M. Iwaya, S. Kamiyama, H. Amano, and I. Akasaki, “Internal quantum efficiency of GaN/AlGaN‐based multi quantum wells on different dislocation densities underlying layers,” Phys. Status Solidi7(7-8c), 1916–1918 (2010).
[CrossRef]

Omiya, H.

A. Bell, S. Srinivasan, C. Plumlee, H. Omiya, F. Ponce, J. Christen, S. Tanaka, A. Fujioka, and Y. Nakagawa, “Exciton freeze-out and thermally activated relaxation at local potential fluctuations in thick AlxGa1-xN layers,” J. Appl. Phys.95(9), 4670–4674 (2004).
[CrossRef]

Onuma, T.

S. Chichibu, K. Hazu, T. Onuma, and A. Uedono, “Collateral evidence for an excellent radiative performance of AlxGa1-xN alloy films of high AlN mole fractions,” Appl. Phys. Lett.99(5), 051902 (2011).
[CrossRef]

T. Onuma, S. F. Chichibu, A. Uedono, T. Sota, P. Cantu, T. M. Katona, J. F. Keading, S. Keller, U. K. Mishra, and S. Nakamura, “Radiative and nonradiative processes in strain-free AlGaN films studied by time-resolved photoluminescence and positron annihilation techniques,” J. Appl. Phys.95(5), 2495 (2004).
[CrossRef]

Paiella, R.

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

Parbrook, P.

K. Lee, P. Parbrook, T. Wang, F. Ranalli, T. Martin, R. Balmer, and D. Wallis, “Optical investigation of exciton localization in AlxGa1-xN,” J. Appl. Phys.101(5), 053513 (2007).
[CrossRef]

Plumlee, C.

A. Bell, S. Srinivasan, C. Plumlee, H. Omiya, F. Ponce, J. Christen, S. Tanaka, A. Fujioka, and Y. Nakagawa, “Exciton freeze-out and thermally activated relaxation at local potential fluctuations in thick AlxGa1-xN layers,” J. Appl. Phys.95(9), 4670–4674 (2004).
[CrossRef]

Ponce, F.

A. Bell, S. Srinivasan, C. Plumlee, H. Omiya, F. Ponce, J. Christen, S. Tanaka, A. Fujioka, and Y. Nakagawa, “Exciton freeze-out and thermally activated relaxation at local potential fluctuations in thick AlxGa1-xN layers,” J. Appl. Phys.95(9), 4670–4674 (2004).
[CrossRef]

Ranalli, F.

K. Lee, P. Parbrook, T. Wang, F. Ranalli, T. Martin, R. Balmer, and D. Wallis, “Optical investigation of exciton localization in AlxGa1-xN,” J. Appl. Phys.101(5), 053513 (2007).
[CrossRef]

Sakai, M.

M. Miyoshi, M. Sakai, H. Ishikawa, T. Egawa, T. Jimbo, M. Tanaka, and O. Oda, “MOVPE growth and characterization of high-Al-content AlGaN/GaN heterostructures on 100-mm-diameter sapphire substrates,” J. Cryst. Growth272(1-4), 293–299 (2004).
[CrossRef]

Scolfaro, L.

L. Teles, J. Furthmüller, L. Scolfaro, J. Leite, and F. Bechstedt, “First-principles calculations of the thermodynamic and structural properties of strained InxGa1-xN and AlxGa1-xN alloys,” Phys. Rev. B62(4), 2475–2485 (2000).
[CrossRef]

Shatalov, M.

E. Kuokstis, W. Sun, M. Shatalov, J. Yang, and M. Asif Khan, “Role of alloy fluctuations in photoluminescence dynamics of AlGaN epilayers,” Appl. Phys. Lett.88(26), 261905 (2006).
[CrossRef]

Shur, M. S.

M. S. Shur and R. Gaska, “Deep-ultraviolet light-emitting diodes,” Electron Devices, IEEE Transactions on57(1), 12–25 (2010).
[CrossRef]

Smith, D. J.

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

Song, J.

Y.-H. Cho, G. Gainer, A. Fischer, J. Song, S. Keller, U. Mishra, and S. DenBaars, ““S-shaped” temperature-dependent emission shift and carrier dynamics in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.73(10), 1370–1372 (1998).
[CrossRef]

Sota, T.

T. Onuma, S. F. Chichibu, A. Uedono, T. Sota, P. Cantu, T. M. Katona, J. F. Keading, S. Keller, U. K. Mishra, and S. Nakamura, “Radiative and nonradiative processes in strain-free AlGaN films studied by time-resolved photoluminescence and positron annihilation techniques,” J. Appl. Phys.95(5), 2495 (2004).
[CrossRef]

Srinivasan, S.

A. Bell, S. Srinivasan, C. Plumlee, H. Omiya, F. Ponce, J. Christen, S. Tanaka, A. Fujioka, and Y. Nakagawa, “Exciton freeze-out and thermally activated relaxation at local potential fluctuations in thick AlxGa1-xN layers,” J. Appl. Phys.95(9), 4670–4674 (2004).
[CrossRef]

Sun, W.

E. Kuokstis, W. Sun, M. Shatalov, J. Yang, and M. Asif Khan, “Role of alloy fluctuations in photoluminescence dynamics of AlGaN epilayers,” Appl. Phys. Lett.88(26), 261905 (2006).
[CrossRef]

Takagahara, T.

H. Gotoh, H. Ando, T. Takagahara, H. Kamada, A. Chavez-Pirson, and J. Temmyo, “Effects of dimensionality on radiative recombination lifetime of excitons in thin quantum boxes of intermediate regime between zero and two Dimensions,” Jpn. J. Appl. Phys.36(Part 1, No. 6B), 4204–4208 (1997).
[CrossRef]

Takano, T.

H. Hirayama, S. Fujikawa, N. Noguchi, J. Norimatsu, T. Takano, K. Tsubaki, and N. Kamata, “222-282 nm AlGaN and InAlGaN-based deep-UV LEDs fabricated on high-quality AlN on sapphire,” Phys. Status Solidi206(6), 1176–1182 (2009) (a).
[CrossRef]

Takeda, K.

K. Takeda, F. Mori, Y. Ogiso, T. Ichikawa, K. Nonaka, M. Iwaya, S. Kamiyama, H. Amano, and I. Akasaki, “Internal quantum efficiency of GaN/AlGaN‐based multi quantum wells on different dislocation densities underlying layers,” Phys. Status Solidi7(7-8c), 1916–1918 (2010).
[CrossRef]

Tanaka, M.

M. Miyoshi, M. Sakai, H. Ishikawa, T. Egawa, T. Jimbo, M. Tanaka, and O. Oda, “MOVPE growth and characterization of high-Al-content AlGaN/GaN heterostructures on 100-mm-diameter sapphire substrates,” J. Cryst. Growth272(1-4), 293–299 (2004).
[CrossRef]

Tanaka, S.

A. Bell, S. Srinivasan, C. Plumlee, H. Omiya, F. Ponce, J. Christen, S. Tanaka, A. Fujioka, and Y. Nakagawa, “Exciton freeze-out and thermally activated relaxation at local potential fluctuations in thick AlxGa1-xN layers,” J. Appl. Phys.95(9), 4670–4674 (2004).
[CrossRef]

Taniyasu, Y.

Y. Taniyasu, M. Kasu, and T. Makimoto, “An aluminium nitride light-emitting diode with a wavelength of 210 nanometres,” Nature441(7091), 325–328 (2006).
[CrossRef] [PubMed]

Teles, L.

L. Teles, J. Furthmüller, L. Scolfaro, J. Leite, and F. Bechstedt, “First-principles calculations of the thermodynamic and structural properties of strained InxGa1-xN and AlxGa1-xN alloys,” Phys. Rev. B62(4), 2475–2485 (2000).
[CrossRef]

Temmyo, J.

H. Gotoh, H. Ando, T. Takagahara, H. Kamada, A. Chavez-Pirson, and J. Temmyo, “Effects of dimensionality on radiative recombination lifetime of excitons in thin quantum boxes of intermediate regime between zero and two Dimensions,” Jpn. J. Appl. Phys.36(Part 1, No. 6B), 4204–4208 (1997).
[CrossRef]

Thomidis, C.

Y. Liao, C. Thomidis, C.- Kao, and T. D. Moustakas, “AlGaN based deep ultraviolet light emitting diodes with high internal quantum efficiency grown by molecular beam epitaxy,” Appl. Phys. Lett.98(8), 081110 (2011).
[CrossRef]

Tsubaki, K.

H. Hirayama, S. Fujikawa, N. Noguchi, J. Norimatsu, T. Takano, K. Tsubaki, and N. Kamata, “222-282 nm AlGaN and InAlGaN-based deep-UV LEDs fabricated on high-quality AlN on sapphire,” Phys. Status Solidi206(6), 1176–1182 (2009) (a).
[CrossRef]

Uedono, A.

S. Chichibu, K. Hazu, T. Onuma, and A. Uedono, “Collateral evidence for an excellent radiative performance of AlxGa1-xN alloy films of high AlN mole fractions,” Appl. Phys. Lett.99(5), 051902 (2011).
[CrossRef]

T. Onuma, S. F. Chichibu, A. Uedono, T. Sota, P. Cantu, T. M. Katona, J. F. Keading, S. Keller, U. K. Mishra, and S. Nakamura, “Radiative and nonradiative processes in strain-free AlGaN films studied by time-resolved photoluminescence and positron annihilation techniques,” J. Appl. Phys.95(5), 2495 (2004).
[CrossRef]

Van de Walle, C. G.

C. G. Van de Walle and J. Neugebauer, “First-principles calculations for defects and impurities: Applications to III-nitrides,” J. Appl. Phys.95(8), 3851–3879 (2004).
[CrossRef]

Van der Stricht, W.

R. Martin, P. Middleton, K. P. O’Donnell, and W. Van der Stricht, “Exciton localization and the Stokes’ shift in InGaN epilayers,” Appl. Phys. Lett.74(2), 263–265 (1999).
[CrossRef]

Wallis, D.

K. Lee, P. Parbrook, T. Wang, F. Ranalli, T. Martin, R. Balmer, and D. Wallis, “Optical investigation of exciton localization in AlxGa1-xN,” J. Appl. Phys.101(5), 053513 (2007).
[CrossRef]

Wang, T.

K. Lee, P. Parbrook, T. Wang, F. Ranalli, T. Martin, R. Balmer, and D. Wallis, “Optical investigation of exciton localization in AlxGa1-xN,” J. Appl. Phys.101(5), 053513 (2007).
[CrossRef]

Wu, C.-Y.

Xu, Z.

J. Huang, X. Dong, X. Luo, X. Liu, Z. Xu, and W. Ge, “Localized exciton dynamics in AlInGaN alloy,” Solid State Commun.126(8), 473–477 (2003).
[CrossRef]

Yang, C.

Y.-S. Lin, K.-J. Ma, C. Hsu, S.-W. Feng, Y.-C. Cheng, C.-C. Liao, C. Yang, C.-C. Chou, C.-M. Lee, and J.-I. Chyi, “Dependence of composition fluctuation on indium content in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.77(19), 2988–2990 (2000).
[CrossRef]

Yang, H.

H. Yang, P. Kuo, T. Lin, Y. Chen, K. Chen, L. Chen, and J.-I. Chyi, “Mechanism of luminescence in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.76(25), 3712–3714 (2000).
[CrossRef]

Yang, J.

E. Kuokstis, W. Sun, M. Shatalov, J. Yang, and M. Asif Khan, “Role of alloy fluctuations in photoluminescence dynamics of AlGaN epilayers,” Appl. Phys. Lett.88(26), 261905 (2006).
[CrossRef]

Yin, J.

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

Zhang, W.

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

Zhou, L.

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

Appl. Phys. Lett. (11)

K. Nam, J. Li, M. Nakarmi, J. Lin, and H. Jiang, “Unique optical properties of AlGaN alloys and related ultraviolet emitters,” Appl. Phys. Lett.84(25), 5264–5266 (2004).
[CrossRef]

H. Yang, P. Kuo, T. Lin, Y. Chen, K. Chen, L. Chen, and J.-I. Chyi, “Mechanism of luminescence in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.76(25), 3712–3714 (2000).
[CrossRef]

R. Martin, P. Middleton, K. P. O’Donnell, and W. Van der Stricht, “Exciton localization and the Stokes’ shift in InGaN epilayers,” Appl. Phys. Lett.74(2), 263–265 (1999).
[CrossRef]

Y.-S. Lin, K.-J. Ma, C. Hsu, S.-W. Feng, Y.-C. Cheng, C.-C. Liao, C. Yang, C.-C. Chou, C.-M. Lee, and J.-I. Chyi, “Dependence of composition fluctuation on indium content in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.77(19), 2988–2990 (2000).
[CrossRef]

Y.-H. Cho, G. Gainer, A. Fischer, J. Song, S. Keller, U. Mishra, and S. DenBaars, ““S-shaped” temperature-dependent emission shift and carrier dynamics in InGaN/GaN multiple quantum wells,” Appl. Phys. Lett.73(10), 1370–1372 (1998).
[CrossRef]

H. Kim, R. Mair, J. Li, J. Lin, and H. Jiang, “Time-resolved photoluminescence studies ofAlxGa1-xNalloys,” Appl. Phys. Lett.76(10), 1252–1254 (2000).
[CrossRef]

N. Nepal, J. Li, M. Nakarmi, J. Lin, and H. Jiang, “Exciton localization in AlGaN alloys,” Appl. Phys. Lett.88(6), 062103 (2006).
[CrossRef]

E. Kuokstis, W. Sun, M. Shatalov, J. Yang, and M. Asif Khan, “Role of alloy fluctuations in photoluminescence dynamics of AlGaN epilayers,” Appl. Phys. Lett.88(26), 261905 (2006).
[CrossRef]

S. Chichibu, K. Hazu, T. Onuma, and A. Uedono, “Collateral evidence for an excellent radiative performance of AlxGa1-xN alloy films of high AlN mole fractions,” Appl. Phys. Lett.99(5), 051902 (2011).
[CrossRef]

Y. Liao, C. Thomidis, C.- Kao, and T. D. Moustakas, “AlGaN based deep ultraviolet light emitting diodes with high internal quantum efficiency grown by molecular beam epitaxy,” Appl. Phys. Lett.98(8), 081110 (2011).
[CrossRef]

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

Electron Devices, IEEE Transactions on (1)

M. S. Shur and R. Gaska, “Deep-ultraviolet light-emitting diodes,” Electron Devices, IEEE Transactions on57(1), 12–25 (2010).
[CrossRef]

J. Appl. Phys. (4)

C. G. Van de Walle and J. Neugebauer, “First-principles calculations for defects and impurities: Applications to III-nitrides,” J. Appl. Phys.95(8), 3851–3879 (2004).
[CrossRef]

T. Onuma, S. F. Chichibu, A. Uedono, T. Sota, P. Cantu, T. M. Katona, J. F. Keading, S. Keller, U. K. Mishra, and S. Nakamura, “Radiative and nonradiative processes in strain-free AlGaN films studied by time-resolved photoluminescence and positron annihilation techniques,” J. Appl. Phys.95(5), 2495 (2004).
[CrossRef]

K. Lee, P. Parbrook, T. Wang, F. Ranalli, T. Martin, R. Balmer, and D. Wallis, “Optical investigation of exciton localization in AlxGa1-xN,” J. Appl. Phys.101(5), 053513 (2007).
[CrossRef]

A. Bell, S. Srinivasan, C. Plumlee, H. Omiya, F. Ponce, J. Christen, S. Tanaka, A. Fujioka, and Y. Nakagawa, “Exciton freeze-out and thermally activated relaxation at local potential fluctuations in thick AlxGa1-xN layers,” J. Appl. Phys.95(9), 4670–4674 (2004).
[CrossRef]

J. Cryst. Growth (1)

M. Miyoshi, M. Sakai, H. Ishikawa, T. Egawa, T. Jimbo, M. Tanaka, and O. Oda, “MOVPE growth and characterization of high-Al-content AlGaN/GaN heterostructures on 100-mm-diameter sapphire substrates,” J. Cryst. Growth272(1-4), 293–299 (2004).
[CrossRef]

Jpn. J. Appl. Phys. (1)

H. Gotoh, H. Ando, T. Takagahara, H. Kamada, A. Chavez-Pirson, and J. Temmyo, “Effects of dimensionality on radiative recombination lifetime of excitons in thin quantum boxes of intermediate regime between zero and two Dimensions,” Jpn. J. Appl. Phys.36(Part 1, No. 6B), 4204–4208 (1997).
[CrossRef]

Nat. Photonics (1)

A. Khan, K. Balakrishnan, and T. Katona, “Ultraviolet light-emitting diodes based on group three nitrides,” Nat. Photonics2(2), 77–84 (2008).
[CrossRef]

Nature (1)

Y. Taniyasu, M. Kasu, and T. Makimoto, “An aluminium nitride light-emitting diode with a wavelength of 210 nanometres,” Nature441(7091), 325–328 (2006).
[CrossRef] [PubMed]

Opt. Express (1)

Phys. Rev. B (2)

R. Banal, M. Funato, and Y. Kawakami, “Optical anisotropy in [0001]-oriented AlxGa1-xN/AlN quantum wells (x> 0.69),” Phys. Rev. B79(12), 121308 (2009).
[CrossRef]

L. Teles, J. Furthmüller, L. Scolfaro, J. Leite, and F. Bechstedt, “First-principles calculations of the thermodynamic and structural properties of strained InxGa1-xN and AlxGa1-xN alloys,” Phys. Rev. B62(4), 2475–2485 (2000).
[CrossRef]

Phys. Rev. Lett. (1)

K. O'Donnell, R. Martin, and P. Middleton, “Origin of luminescence from InGaN diodes,” Phys. Rev. Lett.82(1), 237–240 (1999).
[CrossRef]

Phys. Status Solidi (2)

K. Takeda, F. Mori, Y. Ogiso, T. Ichikawa, K. Nonaka, M. Iwaya, S. Kamiyama, H. Amano, and I. Akasaki, “Internal quantum efficiency of GaN/AlGaN‐based multi quantum wells on different dislocation densities underlying layers,” Phys. Status Solidi7(7-8c), 1916–1918 (2010).
[CrossRef]

H. Hirayama, S. Fujikawa, N. Noguchi, J. Norimatsu, T. Takano, K. Tsubaki, and N. Kamata, “222-282 nm AlGaN and InAlGaN-based deep-UV LEDs fabricated on high-quality AlN on sapphire,” Phys. Status Solidi206(6), 1176–1182 (2009) (a).
[CrossRef]

Solid State Commun. (1)

J. Huang, X. Dong, X. Luo, X. Liu, Z. Xu, and W. Ge, “Localized exciton dynamics in AlInGaN alloy,” Solid State Commun.126(8), 473–477 (2003).
[CrossRef]

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Figures (3)

Fig. 1
Fig. 1

PL spectra for sample A (a) and sample B (b) at temperature ranging from 7 K to 270 K, and temperature dependence of PL peak energies of sample A (c) and sample B (d). These two samples’ emission peaks show an “S-shaped” shift behavior with increasing temperature. The dotted lines in (c) and (d) are the fit of data with the Varshni equation, and the solid lines are the experimental data.

Fig. 2
Fig. 2

Temperature dependent PL decay curves taken at the peak energy of sample A (a) and sample B (b), and temperature dependent emission lifetimes for sample A (c) and sample B (d).

Fig. 3
Fig. 3

Variations of the (a) full width at half maximum (FWHM) of the PL emission line, and (b) exciton localization energy (Eloc) with Al composition x in AlxGa1-xN sample A, B, C, and D.

Tables (1)

Tables Icon

Table 1 Parameters of Sample A, B, C, and D Obtained from XRD and PL Measurements

Equations (6)

Equations on this page are rendered with MathJax. Learn more.

E g (T)= E g (T=0)+α T 2 /(Tβ),
I(t)= I 1 exp(t/ τ 1 )+ I 2 exp(t/ τ 2 ),
I(t)= I 0 exp(t/ τ PL ).
1/ τ PL =1/ τ rad +1/ τ nr ,
τ rad (T)= τ PL (T)/IQE(T),
IQE(T)= PL(T) / PL(T=10K) ,

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