Abstract

Monolithic stacked InGaN light-emitting diode (LED) connected by a polarization-enhanced GaN/AlN-based tunnel junction is demonstrated experimentally in this study. The typical stacked LEDs exhibit 80% enhancement in output power compared with conventional single LEDs because of the repeated use of electrons and holes for photon generation. The typical operation voltage of stacked LEDs is higher than twice the operation voltage of single LEDs. This high operation voltage can be attributed to the non-optimal tunneling junction in stacked LEDs. In addition to the analyses of experimental results, theoretical analysis of different schemes of tunnel junctions, including diagrams of energy bands, diagrams of electric fields, and current-voltage relation curves, are investigated using numerical simulation. The results shown in this paper demonstrate the feasibility in developing cost-effective and highly efficient tunnel-junction LEDs.

© 2017 Optical Society of America

1. Introduction

The III-nitride light-emitting diode (LED) is widely employed in commercial applications from green to ultraviolet spectral range [1, 2]. One of the major issues in the high-power applications of III-nitride LEDs is that of efficiency droop [3, 4] i.e., the reduction of efficiency at high current density. However, although continuous efforts have been exerted to address this problem, an overall solution for efficiency droop remains lacking. Instead of promoting quantum efficiency at high current density, one of the current approaches is to circumvent the efficiency droop issue; this approach is based on the use of monolithic multi-active-region structure cascaded by tunnel junctions (TJs) [5, 6]. In recent years, TJs based on polarization induced charges in the III-nitride materials have been investigated theoretically and experimentally [7–13]. Stacking of multiple LED structures with TJs allows the repeated use of electrons and holes for photon generation in each individual single LED. Thus, the required carrier density in each multi-quantum well (MQW) active region can be reduced effectively for the same level of light output power compared with a single LED. The efficiency profile of the cascaded LED under this approach does not differ significantly from a single LED. However, this approach allows III-nitride LEDs to operate at low current density where internal quantum efficiency is relatively high. The idea is simple, but the manufacturing of cascaded III-nitride LED remains a challenge because of the difficulty in achieving effective III-nitride TJ and the problem in the epitaxial growth of layers subsequent to TJ.

2. Experiment

In this study, two tunnel-junction LED (TJLED) structures with different TJs were fabricated. The LED structures are schematically illustrated in Fig. 1.

 

Fig. 1 Schematic structures of (a) TJLED-1 and (b) TJLED-2.

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All epitaxial wafers were grown on 2-inch c-plane sapphire (0001) substrates through metal-organic chemical vapor deposition (MOCVD). To construct the bottom LED, low-temperature(550 °C) GaN nucleation layer with a thickness of 30 nm was initially deposited on the sapphire substrate, followed by a 2-μm-thick unintentionally doped GaN (u-GaN) buffer layer and a 2.5-μm-thick Si-doped GaN (n+-GaN) layer grown at 1000 °C. On top of the n+-GaN layer, three 2.5-nm-thick In0.15Ga0.85N quantum wells (QWs) sandwiched by four 5-nm-thick GaN barriers were grown at 750 °C, followed by a 100-nm-thick Mg-doped GaN (p-GaN) layer grown at 1000 °C. After growing the bottom LED structure, the TJ structure composed of n++-GaN/p++-In0.1Ga0.9N, which is denoted as TJ-1, and the top LED structure were sequentially grown on the bottom LED structure. The growth temperatures of P++-InGaN layer and the n++-GaN layer in the TJ-1 were 850 °C and 1000 °C, respectively. The ambient gases during the growth of P++-InGaN layer and the n++-GaN layer in the TJ-1 were N2 and H2, respectively. Next, a heavily Si-doped InGaN topmost layer with a thickness of 3 nm was grown on the p-GaN layer of top LED to facilitate the formation of transparent ohmic contact [14]. The stacked LEDs with TJ-1 tunnel junction were labeled as TJLED-1. TJ structure made of n++-GaN/AlN/GaN/AlN/p++-GaN, which is denoted as TJ-2, and the top LED structure were grown sequentially on the bottom LED structure. It should be noted that the growth temperatures of AlN and GaN layers in the TJ-2 were all grown at a temperature of 1000 °C. The ambient gas during the growth of AlN and GaN layers in the TJ-2 was H2. Stacked LEDs with TJ-2 tunnel junction were labeled as TJLED-2. Except for the TJ structure between the top and bottom LEDs, the growth conditions and layer scheme of each top and bottom LED in the TJLED-1 and TJLED-2 are the same.

The detailed layer structures and growth parameters of TJ-1 and TJ-2 are described in Table 1. After epitaxial growth, LED chip with a mesa area of 300 × 300 μm2 was defined using the standard photolithography and dry etching process. Indium tin oxide (ITO) film was deposited on top of TJLEDs, which acts as a transparent current spreading layer. Ni/Au and Ti/Al were then deposited on the ITO layer and on the exposed n+-GaN layer to serve as p-type and n-type bonding pads, respectively.

Tables Icon

Table 1. Layer composition, thickness d (nm), and doping concentration Ndop (1/cm3) of the TJ.

3. Results and discussion

The light output power-current (L-I) and current-voltage (I-V) characteristics of TJLED-1 and TJLED-2 were measured with a calibrated Si photodiode and a programmable source meter. Given an injection current of 20 mA, the light output power (operation voltage) of TJLED-1 and TJLED-2 are 31.9 mW (38.04 V) and 31.0 mW (9.51 V), respectively. The typical L-I characteristics obtained from TJLED-1 and TJLED-2 were similar, as depicted in Fig. 2(a). However, a notable difference can be observed in the I-V characteristics between the two LED structures, that is, the operation voltage of TJLED-1 is larger than that of TJLED-2, as depicted in Fig. 2(b). Theoretically, light output power and operation voltage should be approximately double the size of a single LED when two identical single LED structures are cascaded via the connection of an ideal TJ. The typical operation voltages of TJLED are larger than the theoretical number, especially for TJLED-1, thus, the effectiveness of the designed TJ in the aforesaid cascade LEDs should be examined further. The following section discusses the theoretical simulation results performed with the APSYS simulation program to investigate the characteristics of the TJs utilized in TJLEDs [15].

 

Fig. 2 (a) L-I and (b) I-V characteristics as a function of injection current of TJLED-1 and TJLED-2.

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Carrier transport via band-to-band tunneling could be quite difficult because of the wide bandgap energy of III-nitride materials and the difficulty in achieving degenerate p-type impurity doping [16, 17]. However, the strong polarization-induced electric field provides an opportunity to achieve viable TJs used in GaN-based optoelectronic device structures. The TJ structure (TJ-1) utilized in TJLED-1 is based on the design of Ref. 18 except for the indium composition utilized. Specifically, TJ-1 contains an In0.1Ga0.9N intermediate layer to create polarization-induced surface charges at GaN/In0.1Ga0.9N hetero-interfaces, which provides the polarization field (Ep) in In0.1Ga0.9N layer to induce moderate built-in filed (Ebi). For the TJ structure (TJ-2) utilized in TJLED-2, the multi-layer structure is proposed to adjust the polarization charge profile to enhance the tunneling current. Specifically, the thin AlN/GaN/AlN multi-layers are employed as intermediate region to induce additional polarization charges at the AlN/GaN hetero-interfaces and the polarization field in the thin GaN layer. The heavy p-type doping is moved from the intermediate region to the neighboring GaN layer to facilitate the doping-induced field that covers the entire intermediate region. Figure 3 depicts the calculated energy band diagrams and electric fields of TJ-1 and TJ-2 at equilibrium. The illustrations of the plus/minus signs of the polarization charges at the hetero-interfaces and the direction of built-in and polarization fields can be found in Figs. 3(a) and 3(b). The detailed material parameters employed in the simulation are described elsewhere [19]. The interface charge density induced by spontaneous and piezoelectric polarizations is assumed to be 50% because of the partial compensation of built-in polarization by strain relaxation and imperfect film quality [20]. Figure 3(b) shows that the direction of polarization field for TJ-2 in the intermediate GaN layer is similar to that of the doping-induced built-in field. By contrast, the polarization field in the AlN layers is in the opposite direction of the doping-induced built-in field. Under these circumstances, the total electric field in the GaN intermediate layer of TJ-2 is markedly higher than that in the GaN layer of TJ-1. Thus, the increased electric field in the GaN intermediate layer of TJ-2 results in significant band bending at the AlN/GaN hetero-interfaces to facilitate carrier transport further via tunneling mechanism.

 

Fig. 3 Energy band diagrams and electric fields of (a) (c) TJ-1 and (b) (d) TJ-2 at equilibrium.

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Figure 4 shows that the calculated I-V characteristics of TJ-1 and TJ-2 exhibited a marked difference in current density because the tunneling current density of TJ-2 is almost two orders higher than that of TJ-1 under a given reversed bias. The calculated I-V characteristics of TJ-1 and TJ-2 are consistent with the experimental data showing that TJLED-2 had lower operation voltage than TJLED-1, as shown in Fig. 2(b).

 

Fig. 4 Simulated electrical characteristics of TJ-1 and TJ-2 in the reversed bias regime.

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Additional experiments are performed to explore the device characteristics of TJLED-2 further. First, a single LED identical to the bottom LED structure of TJLED-2 was fabricated as reference, which is denoted as SLED. A TJLED-2 wafer was then cut into two equal pieces. One half of the wafer was etched by 0.3 μm to the n-GaN layer of the top LED, which is denoted as TLED, and the other half of the wafer was etched by 1.1 μm to the n-GaN layer of the bottom LED, which is denoted as TJLED. The structure of TJLED is identical to that of TJLED-2. The insets of Figs. 5(a)-5(c) illustrate the schematic device structures of SLED, TLED, and TJLED, respectively.

 

Fig. 5 Schematic device structures and light-emission images of (a) SLED, (b) TLED, and (c) TJLED chips.

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Figure 6 (a) depicts the typical L-I characteristics of the SLED, TLED, and TJLED. In theory, TJLEDs should be able to generate double light output power compared with SLED or TLED. However, the typical output power of TJLED was slightly lower by twice that of the power output of SLED or TLED. Figure 6(a) shows that the light output power of TLED is less than that of SLED. The small difference in light output power between TLED and SLED might be because of the light absorption at the bottom layers, including the MQW layers in the bottom LED structure. TLED exhibited relatively higher operation voltage as displayed in Fig. 6(b), which could be attributed to its higher series resistance than that of SLED. This higher series resistance is due to the effective thickness (teff) of n-GaN layer (~0.3 mm) in the TLED structure being markedly lower than that of SLED with a teff of approximately 1.1 μm. In other words, SLED with a relatively larger teff of n-GaN layer will have a large current spreading length and low series resistance [21]. Near-field light-emissionimages were taken under different driving currents from SLED and TLED to clarify the effects of current spreading. Figures 5(a)-5(c) show the light emission images of SLED, TLED and TJLED, respectively. SLED displays a uniform top light-emission image. However, a relatively bright area around the n-electrode bonding pad was observed at TLED, indicating significant current crowding and high series resistance. This result is consistent with the I-V characteristics, as shown in Fig. 6(b). Figure 6(c) shows that the peak EQE of SLED is higher than that of TLED when the injection current is lower than 5 mA. Shockley–Read–Hall (SRH) recombination generally governs the transition loss of a LED at low current injection [22]. Compared with SLED, the relatively low peak EQE of TLED driven at low current could be because of the TLED structure grown on a heavily doped p++/n++ GaN junction, which may cause high defect density in the epitaxial layers, and hence, high SRH recombination rate. When the injection current is higher than 5 mA, the EQE curves of the SLED and TLED become comparable. However, the EQE of TLED is slightly less than that of SLED as shown in Fig. 6(c). In addition to the potential absorption of the bottom layers, the slightly lower output power than that of SLEDs, which is obtained at injection current higher than 5 mA from TLEDs, could be attributed to significant current crowding, as shown in Figs. 3 5(a) and 5(b). This contention is evidenced indirectly by the relatively small slope (i.e., larger series resistance) of I-V curve obtained from TLEDs, as shown in Fig. 6(b). The comparison between TLEDs and SLEDs shows that the typical light output power of the TJLEDs was less than the sum of two SLEDs (31.0 mW vs. 17.3 × 2 mW at 20 mA), as shown in Fig. 6(a). The typical operation voltage of a TJLED was higher than the sum of two SLEDs (9.5 V vs. 3.4 × 2 V at 20 mA). In the near-field images of the LED structures, as shown in Fig. 5, it is noted that only TJLED emits with bright spots, and some regions in the emitting surface doesn't emit any light especially near the device periphery. However, images taken from the TLED and SLED showed emitting surface without bright spots. The difference could be attributed to the fact that the thickness of AlN layer in the embedded TJ is not uniform to cause the tunneling junction electrically inactive at some local regions. In addition, as shown in the inset of Fig. 6(c), the wall-plug efficiency of TJLED is still far lower than the SLED because the turn-on voltage of TJLED is still far higher than the theoretical number, as shown Fig. 6(b). Therefore, the performances of AlN/GaN/AlN TJ should be further improved to enhance the wall-plug efficiency of the TJLED. Figure 6(d) displays typical electroluminescence (EL) spectra taken from the experimental LEDs driven at a DC currentof 20 mA. It is shown that all the LEDs exhibited a single peak at approximately 450 nm. The single-peak EL spectrum indicates that two unit LEDs connected via TJ in the TJLED emitted nearly the same EL spectra.

 

Fig. 6 (a) L-I, (b) I-V, (c) EQE, WPE (inset), and (d) EL spectral characteristics of SLED, TLED, and TJLED.

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4. Conclusion

In summary, monolithic stacked blue InGaN LEDs connected by polarization-enhanced AlN/GaN/AlN TJs were demonstrated. The experimental results and theoretical simulation indicated that TJ is the key to realizing efficient TJLEDs. In this study, the light output power of TJLED exhibited 80% enhancement in output power compared with conventional SLED. However, electric performance from TJLED was not as good as expected. Given an injection current of 20 mA, the operation voltage of TJLED was 40% higher than twice that of SLED. This result is because of the non-optimal TJ caused by the difficulty in growing high-quality AlN layer and achieving heavily Mg-doped p++-GaN layer.

Funding

Ministry of Science and Technology of Taiwan (MOST-105-2112-M-018-005-MY3, MOST 104-2112-M-006-009-MY3 and MOST 104-2221-E-218-011-MY3).

References and links

1. S. Nakamura, M. Senoh, N. Iwasa, and S. Nagahama, “High-brightness InGaN blue, green and yellow light-emitting diodes with quantum well structures,” Jpn. J. Appl. Phys. 34(Part 2, No. 7A), L797–L799 (1995). [CrossRef]  

2. Y. Taniyasu, M. Kasu, and T. Makimoto, “An aluminium nitride light-emitting diode with a wavelength of 210 nanometres,” Nature 441(7091), 325–328 (2006). [CrossRef]   [PubMed]  

3. J. Piprek, “Efficiency droop in nitride-based light-emitting diodes,” Phys. Status Solidi., A Appl. Mater. Sci. 207(10), 2217–2225 (2010). [CrossRef]  

4. Y.-K. Kuo and J.-Y. Chang, “Investigation of degraded efficiency in blue InGaN multiple-quantum well light-emitting diodes,” Proc. SPIE 9357, 93571L (2015). [CrossRef]  

5. F. Akyol, S. Krishnamoorthy, and S. Rajan, “Tunneling-based carrier regeneration in cascaded GaN light emitting diodes to overcome efficiency droop,” Appl. Phys. Lett. 103(8), 081107 (2013). [CrossRef]  

6. J. Piprek, “Origin of InGaN/GaN light-emitting diode efficiency improvements using tunnel-junction-cascaded active regions,” Appl. Phys. Lett. 104(5), 051118 (2014). [CrossRef]  

7. M. F. Schubert, “Interband tunnel junctions for wurtzite III-nitride semiconductors based on heterointerface polarization charges,” Phys. Rev. B 81(3), 035303 (2010). [CrossRef]  

8. S. Krishnamoorthy, P. S. Park, and S. Rajan, “Demonstration of forward inter-band tunneling in GaN by polarization engineering,” Appl. Phys. Lett. 99(23), 233504 (2011). [CrossRef]  

9. S. Krishnamoorthy, F. Akyol, P. S. Park, and S. Rajan, “Low resistance GaN/InGaN/GaN tunnel junctions,” Appl. Phys. Lett. 102(11), 113503 (2013). [CrossRef]  

10. M. Kaga, T. Morita, Y. Kuwano, K. Yamashita, K. Yagi, M. Iwaya, T. Takeuchi, S. Kamiyama, and I. Akasaki, “GaInN-based tunnel junctions in n–p–n light emitting diodes,” Jpn. J. Appl. Phys. 52(8S), 08JH06 (2013). [CrossRef]  

11. S.-J. Chang, W.-H. Lin, and W.-S. Chen, “Cascaded GaN light-emitting diodes with hybrid tunnel junction layers,” IEEE J. Quantum Electron. 51(8), 3300505 (2015). [CrossRef]  

12. F. Akyol, S. Krishnamoorthy, Y. Zhang, and S. Rajan, “GaN-based three-junction cascaded light-emitting diode with low-resistance InGaN tunnel junctions,” Appl. Phys. Express 8(8), 082103 (2015). [CrossRef]  

13. D. Takasuka, Y. Akatsuka, M. Ino, N. Koide, T. Takeuchi, M. Iwaya, S. Kamiyama, and I. Akasaki, “GaInN-based tunnel junctions with graded layers,” Appl. Phys. Express 9(8), 081005 (2016). [CrossRef]  

14. J.-K. Sheu, J.-M. Tsai, S.-C. Shei, W.-C. Lai, T.-C. Wen, C.-H. Kou, Y.-K. Su, S.-J. Chang, and G.-C. Chi, “Low-operation voltage of InGaN-GaN light-emitting diodes with Si-doped In0.3Ga 0.7N/GaN short-period superlattice tunneling contact layer,” IEEE Electron Device Lett. 22(10), 460–462 (2001). [CrossRef]  

15. APSYS by Crosslight Software Inc, Burnaby, Canada, http://www.croslight.com.

16. J. Simon, Z. Zhang, K. Goodman, H. Xing, T. Kosel, P. Fay, and D. Jena, “Polarization-induced zener tunnel junctions in wide-band-gap heterostructures,” Phys. Rev. Lett. 103(2), 026801 (2009). [CrossRef]   [PubMed]  

17. S. Krishnamoorthy, D. N. Nath, F. Akyol, P. S. Park, M. Esposto, and S. Rajan, “Polarization-engineered GaN/InGaN/GaN tunnel diodes,” Appl. Phys. Lett. 97(20), 203502 (2010). [CrossRef]  

18. I. Ozden, E. Makarona, A. V. Nurmikko, T. Takeuchi, and M. Krames, “A dual-wavelength indium gallium nitride quantum well light emitting diode,” Appl. Phys. Lett. 79(16), 2532–2534 (2001). [CrossRef]  

19. Y.-H. Shih, J.-Y. Chang, J.-K. Sheu, Y.-K. Kuo, F.-M. Chen, M.-L. Lee, and W.-C. Lai, “Design of hole-blocking and electron-blocking layers in AlxGa1–xN-based UV light-emitting diodes,” IEEE Trans. Electron Dev. 63(3), 1141–1147 (2016). [CrossRef]  

20. J. Piprek, Nitride Semiconductor Devices: Principles and Simulation (Wiley-VCH verlag, 2007), pp. 423–445.

21. E. F. Schubert, Light-Emitting Diodes (Cambridge University, 2006), pp 137–141.

22. M. F. Schubert, S. Chhajed, J. K. Kim, E. F. Schubert, D. D. Koleske, M. H. Crawford, S. R. Lee, A. J. Fischer, G. Thaler, and M. A. Banas, “Effect of dislocation density on efficiency droop in GaInN/GaN/GaInN/GaN light-emitting diodes,” Appl. Phys. Lett. 91(23), 231114 (2007). [CrossRef]  

References

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  1. S. Nakamura, M. Senoh, N. Iwasa, and S. Nagahama, “High-brightness InGaN blue, green and yellow light-emitting diodes with quantum well structures,” Jpn. J. Appl. Phys. 34(Part 2, No. 7A), L797–L799 (1995).
    [Crossref]
  2. Y. Taniyasu, M. Kasu, and T. Makimoto, “An aluminium nitride light-emitting diode with a wavelength of 210 nanometres,” Nature 441(7091), 325–328 (2006).
    [Crossref] [PubMed]
  3. J. Piprek, “Efficiency droop in nitride-based light-emitting diodes,” Phys. Status Solidi., A Appl. Mater. Sci. 207(10), 2217–2225 (2010).
    [Crossref]
  4. Y.-K. Kuo and J.-Y. Chang, “Investigation of degraded efficiency in blue InGaN multiple-quantum well light-emitting diodes,” Proc. SPIE 9357, 93571L (2015).
    [Crossref]
  5. F. Akyol, S. Krishnamoorthy, and S. Rajan, “Tunneling-based carrier regeneration in cascaded GaN light emitting diodes to overcome efficiency droop,” Appl. Phys. Lett. 103(8), 081107 (2013).
    [Crossref]
  6. J. Piprek, “Origin of InGaN/GaN light-emitting diode efficiency improvements using tunnel-junction-cascaded active regions,” Appl. Phys. Lett. 104(5), 051118 (2014).
    [Crossref]
  7. M. F. Schubert, “Interband tunnel junctions for wurtzite III-nitride semiconductors based on heterointerface polarization charges,” Phys. Rev. B 81(3), 035303 (2010).
    [Crossref]
  8. S. Krishnamoorthy, P. S. Park, and S. Rajan, “Demonstration of forward inter-band tunneling in GaN by polarization engineering,” Appl. Phys. Lett. 99(23), 233504 (2011).
    [Crossref]
  9. S. Krishnamoorthy, F. Akyol, P. S. Park, and S. Rajan, “Low resistance GaN/InGaN/GaN tunnel junctions,” Appl. Phys. Lett. 102(11), 113503 (2013).
    [Crossref]
  10. M. Kaga, T. Morita, Y. Kuwano, K. Yamashita, K. Yagi, M. Iwaya, T. Takeuchi, S. Kamiyama, and I. Akasaki, “GaInN-based tunnel junctions in n–p–n light emitting diodes,” Jpn. J. Appl. Phys. 52(8S), 08JH06 (2013).
    [Crossref]
  11. S.-J. Chang, W.-H. Lin, and W.-S. Chen, “Cascaded GaN light-emitting diodes with hybrid tunnel junction layers,” IEEE J. Quantum Electron. 51(8), 3300505 (2015).
    [Crossref]
  12. F. Akyol, S. Krishnamoorthy, Y. Zhang, and S. Rajan, “GaN-based three-junction cascaded light-emitting diode with low-resistance InGaN tunnel junctions,” Appl. Phys. Express 8(8), 082103 (2015).
    [Crossref]
  13. D. Takasuka, Y. Akatsuka, M. Ino, N. Koide, T. Takeuchi, M. Iwaya, S. Kamiyama, and I. Akasaki, “GaInN-based tunnel junctions with graded layers,” Appl. Phys. Express 9(8), 081005 (2016).
    [Crossref]
  14. J.-K. Sheu, J.-M. Tsai, S.-C. Shei, W.-C. Lai, T.-C. Wen, C.-H. Kou, Y.-K. Su, S.-J. Chang, and G.-C. Chi, “Low-operation voltage of InGaN-GaN light-emitting diodes with Si-doped In0.3Ga 0.7N/GaN short-period superlattice tunneling contact layer,” IEEE Electron Device Lett. 22(10), 460–462 (2001).
    [Crossref]
  15. APSYS by Crosslight Software Inc, Burnaby, Canada, http://www.croslight.com .
  16. J. Simon, Z. Zhang, K. Goodman, H. Xing, T. Kosel, P. Fay, and D. Jena, “Polarization-induced zener tunnel junctions in wide-band-gap heterostructures,” Phys. Rev. Lett. 103(2), 026801 (2009).
    [Crossref] [PubMed]
  17. S. Krishnamoorthy, D. N. Nath, F. Akyol, P. S. Park, M. Esposto, and S. Rajan, “Polarization-engineered GaN/InGaN/GaN tunnel diodes,” Appl. Phys. Lett. 97(20), 203502 (2010).
    [Crossref]
  18. I. Ozden, E. Makarona, A. V. Nurmikko, T. Takeuchi, and M. Krames, “A dual-wavelength indium gallium nitride quantum well light emitting diode,” Appl. Phys. Lett. 79(16), 2532–2534 (2001).
    [Crossref]
  19. Y.-H. Shih, J.-Y. Chang, J.-K. Sheu, Y.-K. Kuo, F.-M. Chen, M.-L. Lee, and W.-C. Lai, “Design of hole-blocking and electron-blocking layers in AlxGa1–xN-based UV light-emitting diodes,” IEEE Trans. Electron Dev. 63(3), 1141–1147 (2016).
    [Crossref]
  20. J. Piprek, Nitride Semiconductor Devices: Principles and Simulation (Wiley-VCH verlag, 2007), pp. 423–445.
  21. E. F. Schubert, Light-Emitting Diodes (Cambridge University, 2006), pp 137–141.
  22. M. F. Schubert, S. Chhajed, J. K. Kim, E. F. Schubert, D. D. Koleske, M. H. Crawford, S. R. Lee, A. J. Fischer, G. Thaler, and M. A. Banas, “Effect of dislocation density on efficiency droop in GaInN/GaN/GaInN/GaN light-emitting diodes,” Appl. Phys. Lett. 91(23), 231114 (2007).
    [Crossref]

2016 (2)

D. Takasuka, Y. Akatsuka, M. Ino, N. Koide, T. Takeuchi, M. Iwaya, S. Kamiyama, and I. Akasaki, “GaInN-based tunnel junctions with graded layers,” Appl. Phys. Express 9(8), 081005 (2016).
[Crossref]

Y.-H. Shih, J.-Y. Chang, J.-K. Sheu, Y.-K. Kuo, F.-M. Chen, M.-L. Lee, and W.-C. Lai, “Design of hole-blocking and electron-blocking layers in AlxGa1–xN-based UV light-emitting diodes,” IEEE Trans. Electron Dev. 63(3), 1141–1147 (2016).
[Crossref]

2015 (3)

S.-J. Chang, W.-H. Lin, and W.-S. Chen, “Cascaded GaN light-emitting diodes with hybrid tunnel junction layers,” IEEE J. Quantum Electron. 51(8), 3300505 (2015).
[Crossref]

F. Akyol, S. Krishnamoorthy, Y. Zhang, and S. Rajan, “GaN-based three-junction cascaded light-emitting diode with low-resistance InGaN tunnel junctions,” Appl. Phys. Express 8(8), 082103 (2015).
[Crossref]

Y.-K. Kuo and J.-Y. Chang, “Investigation of degraded efficiency in blue InGaN multiple-quantum well light-emitting diodes,” Proc. SPIE 9357, 93571L (2015).
[Crossref]

2014 (1)

J. Piprek, “Origin of InGaN/GaN light-emitting diode efficiency improvements using tunnel-junction-cascaded active regions,” Appl. Phys. Lett. 104(5), 051118 (2014).
[Crossref]

2013 (3)

F. Akyol, S. Krishnamoorthy, and S. Rajan, “Tunneling-based carrier regeneration in cascaded GaN light emitting diodes to overcome efficiency droop,” Appl. Phys. Lett. 103(8), 081107 (2013).
[Crossref]

S. Krishnamoorthy, F. Akyol, P. S. Park, and S. Rajan, “Low resistance GaN/InGaN/GaN tunnel junctions,” Appl. Phys. Lett. 102(11), 113503 (2013).
[Crossref]

M. Kaga, T. Morita, Y. Kuwano, K. Yamashita, K. Yagi, M. Iwaya, T. Takeuchi, S. Kamiyama, and I. Akasaki, “GaInN-based tunnel junctions in n–p–n light emitting diodes,” Jpn. J. Appl. Phys. 52(8S), 08JH06 (2013).
[Crossref]

2011 (1)

S. Krishnamoorthy, P. S. Park, and S. Rajan, “Demonstration of forward inter-band tunneling in GaN by polarization engineering,” Appl. Phys. Lett. 99(23), 233504 (2011).
[Crossref]

2010 (3)

J. Piprek, “Efficiency droop in nitride-based light-emitting diodes,” Phys. Status Solidi., A Appl. Mater. Sci. 207(10), 2217–2225 (2010).
[Crossref]

M. F. Schubert, “Interband tunnel junctions for wurtzite III-nitride semiconductors based on heterointerface polarization charges,” Phys. Rev. B 81(3), 035303 (2010).
[Crossref]

S. Krishnamoorthy, D. N. Nath, F. Akyol, P. S. Park, M. Esposto, and S. Rajan, “Polarization-engineered GaN/InGaN/GaN tunnel diodes,” Appl. Phys. Lett. 97(20), 203502 (2010).
[Crossref]

2009 (1)

J. Simon, Z. Zhang, K. Goodman, H. Xing, T. Kosel, P. Fay, and D. Jena, “Polarization-induced zener tunnel junctions in wide-band-gap heterostructures,” Phys. Rev. Lett. 103(2), 026801 (2009).
[Crossref] [PubMed]

2007 (1)

M. F. Schubert, S. Chhajed, J. K. Kim, E. F. Schubert, D. D. Koleske, M. H. Crawford, S. R. Lee, A. J. Fischer, G. Thaler, and M. A. Banas, “Effect of dislocation density on efficiency droop in GaInN/GaN/GaInN/GaN light-emitting diodes,” Appl. Phys. Lett. 91(23), 231114 (2007).
[Crossref]

2006 (1)

Y. Taniyasu, M. Kasu, and T. Makimoto, “An aluminium nitride light-emitting diode with a wavelength of 210 nanometres,” Nature 441(7091), 325–328 (2006).
[Crossref] [PubMed]

2001 (2)

I. Ozden, E. Makarona, A. V. Nurmikko, T. Takeuchi, and M. Krames, “A dual-wavelength indium gallium nitride quantum well light emitting diode,” Appl. Phys. Lett. 79(16), 2532–2534 (2001).
[Crossref]

J.-K. Sheu, J.-M. Tsai, S.-C. Shei, W.-C. Lai, T.-C. Wen, C.-H. Kou, Y.-K. Su, S.-J. Chang, and G.-C. Chi, “Low-operation voltage of InGaN-GaN light-emitting diodes with Si-doped In0.3Ga 0.7N/GaN short-period superlattice tunneling contact layer,” IEEE Electron Device Lett. 22(10), 460–462 (2001).
[Crossref]

1995 (1)

S. Nakamura, M. Senoh, N. Iwasa, and S. Nagahama, “High-brightness InGaN blue, green and yellow light-emitting diodes with quantum well structures,” Jpn. J. Appl. Phys. 34(Part 2, No. 7A), L797–L799 (1995).
[Crossref]

Akasaki, I.

D. Takasuka, Y. Akatsuka, M. Ino, N. Koide, T. Takeuchi, M. Iwaya, S. Kamiyama, and I. Akasaki, “GaInN-based tunnel junctions with graded layers,” Appl. Phys. Express 9(8), 081005 (2016).
[Crossref]

M. Kaga, T. Morita, Y. Kuwano, K. Yamashita, K. Yagi, M. Iwaya, T. Takeuchi, S. Kamiyama, and I. Akasaki, “GaInN-based tunnel junctions in n–p–n light emitting diodes,” Jpn. J. Appl. Phys. 52(8S), 08JH06 (2013).
[Crossref]

Akatsuka, Y.

D. Takasuka, Y. Akatsuka, M. Ino, N. Koide, T. Takeuchi, M. Iwaya, S. Kamiyama, and I. Akasaki, “GaInN-based tunnel junctions with graded layers,” Appl. Phys. Express 9(8), 081005 (2016).
[Crossref]

Akyol, F.

F. Akyol, S. Krishnamoorthy, Y. Zhang, and S. Rajan, “GaN-based three-junction cascaded light-emitting diode with low-resistance InGaN tunnel junctions,” Appl. Phys. Express 8(8), 082103 (2015).
[Crossref]

F. Akyol, S. Krishnamoorthy, and S. Rajan, “Tunneling-based carrier regeneration in cascaded GaN light emitting diodes to overcome efficiency droop,” Appl. Phys. Lett. 103(8), 081107 (2013).
[Crossref]

S. Krishnamoorthy, F. Akyol, P. S. Park, and S. Rajan, “Low resistance GaN/InGaN/GaN tunnel junctions,” Appl. Phys. Lett. 102(11), 113503 (2013).
[Crossref]

S. Krishnamoorthy, D. N. Nath, F. Akyol, P. S. Park, M. Esposto, and S. Rajan, “Polarization-engineered GaN/InGaN/GaN tunnel diodes,” Appl. Phys. Lett. 97(20), 203502 (2010).
[Crossref]

Banas, M. A.

M. F. Schubert, S. Chhajed, J. K. Kim, E. F. Schubert, D. D. Koleske, M. H. Crawford, S. R. Lee, A. J. Fischer, G. Thaler, and M. A. Banas, “Effect of dislocation density on efficiency droop in GaInN/GaN/GaInN/GaN light-emitting diodes,” Appl. Phys. Lett. 91(23), 231114 (2007).
[Crossref]

Chang, J.-Y.

Y.-H. Shih, J.-Y. Chang, J.-K. Sheu, Y.-K. Kuo, F.-M. Chen, M.-L. Lee, and W.-C. Lai, “Design of hole-blocking and electron-blocking layers in AlxGa1–xN-based UV light-emitting diodes,” IEEE Trans. Electron Dev. 63(3), 1141–1147 (2016).
[Crossref]

Y.-K. Kuo and J.-Y. Chang, “Investigation of degraded efficiency in blue InGaN multiple-quantum well light-emitting diodes,” Proc. SPIE 9357, 93571L (2015).
[Crossref]

Chang, S.-J.

S.-J. Chang, W.-H. Lin, and W.-S. Chen, “Cascaded GaN light-emitting diodes with hybrid tunnel junction layers,” IEEE J. Quantum Electron. 51(8), 3300505 (2015).
[Crossref]

J.-K. Sheu, J.-M. Tsai, S.-C. Shei, W.-C. Lai, T.-C. Wen, C.-H. Kou, Y.-K. Su, S.-J. Chang, and G.-C. Chi, “Low-operation voltage of InGaN-GaN light-emitting diodes with Si-doped In0.3Ga 0.7N/GaN short-period superlattice tunneling contact layer,” IEEE Electron Device Lett. 22(10), 460–462 (2001).
[Crossref]

Chen, F.-M.

Y.-H. Shih, J.-Y. Chang, J.-K. Sheu, Y.-K. Kuo, F.-M. Chen, M.-L. Lee, and W.-C. Lai, “Design of hole-blocking and electron-blocking layers in AlxGa1–xN-based UV light-emitting diodes,” IEEE Trans. Electron Dev. 63(3), 1141–1147 (2016).
[Crossref]

Chen, W.-S.

S.-J. Chang, W.-H. Lin, and W.-S. Chen, “Cascaded GaN light-emitting diodes with hybrid tunnel junction layers,” IEEE J. Quantum Electron. 51(8), 3300505 (2015).
[Crossref]

Chhajed, S.

M. F. Schubert, S. Chhajed, J. K. Kim, E. F. Schubert, D. D. Koleske, M. H. Crawford, S. R. Lee, A. J. Fischer, G. Thaler, and M. A. Banas, “Effect of dislocation density on efficiency droop in GaInN/GaN/GaInN/GaN light-emitting diodes,” Appl. Phys. Lett. 91(23), 231114 (2007).
[Crossref]

Chi, G.-C.

J.-K. Sheu, J.-M. Tsai, S.-C. Shei, W.-C. Lai, T.-C. Wen, C.-H. Kou, Y.-K. Su, S.-J. Chang, and G.-C. Chi, “Low-operation voltage of InGaN-GaN light-emitting diodes with Si-doped In0.3Ga 0.7N/GaN short-period superlattice tunneling contact layer,” IEEE Electron Device Lett. 22(10), 460–462 (2001).
[Crossref]

Crawford, M. H.

M. F. Schubert, S. Chhajed, J. K. Kim, E. F. Schubert, D. D. Koleske, M. H. Crawford, S. R. Lee, A. J. Fischer, G. Thaler, and M. A. Banas, “Effect of dislocation density on efficiency droop in GaInN/GaN/GaInN/GaN light-emitting diodes,” Appl. Phys. Lett. 91(23), 231114 (2007).
[Crossref]

Esposto, M.

S. Krishnamoorthy, D. N. Nath, F. Akyol, P. S. Park, M. Esposto, and S. Rajan, “Polarization-engineered GaN/InGaN/GaN tunnel diodes,” Appl. Phys. Lett. 97(20), 203502 (2010).
[Crossref]

Fay, P.

J. Simon, Z. Zhang, K. Goodman, H. Xing, T. Kosel, P. Fay, and D. Jena, “Polarization-induced zener tunnel junctions in wide-band-gap heterostructures,” Phys. Rev. Lett. 103(2), 026801 (2009).
[Crossref] [PubMed]

Fischer, A. J.

M. F. Schubert, S. Chhajed, J. K. Kim, E. F. Schubert, D. D. Koleske, M. H. Crawford, S. R. Lee, A. J. Fischer, G. Thaler, and M. A. Banas, “Effect of dislocation density on efficiency droop in GaInN/GaN/GaInN/GaN light-emitting diodes,” Appl. Phys. Lett. 91(23), 231114 (2007).
[Crossref]

Goodman, K.

J. Simon, Z. Zhang, K. Goodman, H. Xing, T. Kosel, P. Fay, and D. Jena, “Polarization-induced zener tunnel junctions in wide-band-gap heterostructures,” Phys. Rev. Lett. 103(2), 026801 (2009).
[Crossref] [PubMed]

Ino, M.

D. Takasuka, Y. Akatsuka, M. Ino, N. Koide, T. Takeuchi, M. Iwaya, S. Kamiyama, and I. Akasaki, “GaInN-based tunnel junctions with graded layers,” Appl. Phys. Express 9(8), 081005 (2016).
[Crossref]

Iwasa, N.

S. Nakamura, M. Senoh, N. Iwasa, and S. Nagahama, “High-brightness InGaN blue, green and yellow light-emitting diodes with quantum well structures,” Jpn. J. Appl. Phys. 34(Part 2, No. 7A), L797–L799 (1995).
[Crossref]

Iwaya, M.

D. Takasuka, Y. Akatsuka, M. Ino, N. Koide, T. Takeuchi, M. Iwaya, S. Kamiyama, and I. Akasaki, “GaInN-based tunnel junctions with graded layers,” Appl. Phys. Express 9(8), 081005 (2016).
[Crossref]

M. Kaga, T. Morita, Y. Kuwano, K. Yamashita, K. Yagi, M. Iwaya, T. Takeuchi, S. Kamiyama, and I. Akasaki, “GaInN-based tunnel junctions in n–p–n light emitting diodes,” Jpn. J. Appl. Phys. 52(8S), 08JH06 (2013).
[Crossref]

Jena, D.

J. Simon, Z. Zhang, K. Goodman, H. Xing, T. Kosel, P. Fay, and D. Jena, “Polarization-induced zener tunnel junctions in wide-band-gap heterostructures,” Phys. Rev. Lett. 103(2), 026801 (2009).
[Crossref] [PubMed]

Kaga, M.

M. Kaga, T. Morita, Y. Kuwano, K. Yamashita, K. Yagi, M. Iwaya, T. Takeuchi, S. Kamiyama, and I. Akasaki, “GaInN-based tunnel junctions in n–p–n light emitting diodes,” Jpn. J. Appl. Phys. 52(8S), 08JH06 (2013).
[Crossref]

Kamiyama, S.

D. Takasuka, Y. Akatsuka, M. Ino, N. Koide, T. Takeuchi, M. Iwaya, S. Kamiyama, and I. Akasaki, “GaInN-based tunnel junctions with graded layers,” Appl. Phys. Express 9(8), 081005 (2016).
[Crossref]

M. Kaga, T. Morita, Y. Kuwano, K. Yamashita, K. Yagi, M. Iwaya, T. Takeuchi, S. Kamiyama, and I. Akasaki, “GaInN-based tunnel junctions in n–p–n light emitting diodes,” Jpn. J. Appl. Phys. 52(8S), 08JH06 (2013).
[Crossref]

Kasu, M.

Y. Taniyasu, M. Kasu, and T. Makimoto, “An aluminium nitride light-emitting diode with a wavelength of 210 nanometres,” Nature 441(7091), 325–328 (2006).
[Crossref] [PubMed]

Kim, J. K.

M. F. Schubert, S. Chhajed, J. K. Kim, E. F. Schubert, D. D. Koleske, M. H. Crawford, S. R. Lee, A. J. Fischer, G. Thaler, and M. A. Banas, “Effect of dislocation density on efficiency droop in GaInN/GaN/GaInN/GaN light-emitting diodes,” Appl. Phys. Lett. 91(23), 231114 (2007).
[Crossref]

Koide, N.

D. Takasuka, Y. Akatsuka, M. Ino, N. Koide, T. Takeuchi, M. Iwaya, S. Kamiyama, and I. Akasaki, “GaInN-based tunnel junctions with graded layers,” Appl. Phys. Express 9(8), 081005 (2016).
[Crossref]

Koleske, D. D.

M. F. Schubert, S. Chhajed, J. K. Kim, E. F. Schubert, D. D. Koleske, M. H. Crawford, S. R. Lee, A. J. Fischer, G. Thaler, and M. A. Banas, “Effect of dislocation density on efficiency droop in GaInN/GaN/GaInN/GaN light-emitting diodes,” Appl. Phys. Lett. 91(23), 231114 (2007).
[Crossref]

Kosel, T.

J. Simon, Z. Zhang, K. Goodman, H. Xing, T. Kosel, P. Fay, and D. Jena, “Polarization-induced zener tunnel junctions in wide-band-gap heterostructures,” Phys. Rev. Lett. 103(2), 026801 (2009).
[Crossref] [PubMed]

Kou, C.-H.

J.-K. Sheu, J.-M. Tsai, S.-C. Shei, W.-C. Lai, T.-C. Wen, C.-H. Kou, Y.-K. Su, S.-J. Chang, and G.-C. Chi, “Low-operation voltage of InGaN-GaN light-emitting diodes with Si-doped In0.3Ga 0.7N/GaN short-period superlattice tunneling contact layer,” IEEE Electron Device Lett. 22(10), 460–462 (2001).
[Crossref]

Krames, M.

I. Ozden, E. Makarona, A. V. Nurmikko, T. Takeuchi, and M. Krames, “A dual-wavelength indium gallium nitride quantum well light emitting diode,” Appl. Phys. Lett. 79(16), 2532–2534 (2001).
[Crossref]

Krishnamoorthy, S.

F. Akyol, S. Krishnamoorthy, Y. Zhang, and S. Rajan, “GaN-based three-junction cascaded light-emitting diode with low-resistance InGaN tunnel junctions,” Appl. Phys. Express 8(8), 082103 (2015).
[Crossref]

S. Krishnamoorthy, F. Akyol, P. S. Park, and S. Rajan, “Low resistance GaN/InGaN/GaN tunnel junctions,” Appl. Phys. Lett. 102(11), 113503 (2013).
[Crossref]

F. Akyol, S. Krishnamoorthy, and S. Rajan, “Tunneling-based carrier regeneration in cascaded GaN light emitting diodes to overcome efficiency droop,” Appl. Phys. Lett. 103(8), 081107 (2013).
[Crossref]

S. Krishnamoorthy, P. S. Park, and S. Rajan, “Demonstration of forward inter-band tunneling in GaN by polarization engineering,” Appl. Phys. Lett. 99(23), 233504 (2011).
[Crossref]

S. Krishnamoorthy, D. N. Nath, F. Akyol, P. S. Park, M. Esposto, and S. Rajan, “Polarization-engineered GaN/InGaN/GaN tunnel diodes,” Appl. Phys. Lett. 97(20), 203502 (2010).
[Crossref]

Kuo, Y.-K.

Y.-H. Shih, J.-Y. Chang, J.-K. Sheu, Y.-K. Kuo, F.-M. Chen, M.-L. Lee, and W.-C. Lai, “Design of hole-blocking and electron-blocking layers in AlxGa1–xN-based UV light-emitting diodes,” IEEE Trans. Electron Dev. 63(3), 1141–1147 (2016).
[Crossref]

Y.-K. Kuo and J.-Y. Chang, “Investigation of degraded efficiency in blue InGaN multiple-quantum well light-emitting diodes,” Proc. SPIE 9357, 93571L (2015).
[Crossref]

Kuwano, Y.

M. Kaga, T. Morita, Y. Kuwano, K. Yamashita, K. Yagi, M. Iwaya, T. Takeuchi, S. Kamiyama, and I. Akasaki, “GaInN-based tunnel junctions in n–p–n light emitting diodes,” Jpn. J. Appl. Phys. 52(8S), 08JH06 (2013).
[Crossref]

Lai, W.-C.

Y.-H. Shih, J.-Y. Chang, J.-K. Sheu, Y.-K. Kuo, F.-M. Chen, M.-L. Lee, and W.-C. Lai, “Design of hole-blocking and electron-blocking layers in AlxGa1–xN-based UV light-emitting diodes,” IEEE Trans. Electron Dev. 63(3), 1141–1147 (2016).
[Crossref]

J.-K. Sheu, J.-M. Tsai, S.-C. Shei, W.-C. Lai, T.-C. Wen, C.-H. Kou, Y.-K. Su, S.-J. Chang, and G.-C. Chi, “Low-operation voltage of InGaN-GaN light-emitting diodes with Si-doped In0.3Ga 0.7N/GaN short-period superlattice tunneling contact layer,” IEEE Electron Device Lett. 22(10), 460–462 (2001).
[Crossref]

Lee, M.-L.

Y.-H. Shih, J.-Y. Chang, J.-K. Sheu, Y.-K. Kuo, F.-M. Chen, M.-L. Lee, and W.-C. Lai, “Design of hole-blocking and electron-blocking layers in AlxGa1–xN-based UV light-emitting diodes,” IEEE Trans. Electron Dev. 63(3), 1141–1147 (2016).
[Crossref]

Lee, S. R.

M. F. Schubert, S. Chhajed, J. K. Kim, E. F. Schubert, D. D. Koleske, M. H. Crawford, S. R. Lee, A. J. Fischer, G. Thaler, and M. A. Banas, “Effect of dislocation density on efficiency droop in GaInN/GaN/GaInN/GaN light-emitting diodes,” Appl. Phys. Lett. 91(23), 231114 (2007).
[Crossref]

Lin, W.-H.

S.-J. Chang, W.-H. Lin, and W.-S. Chen, “Cascaded GaN light-emitting diodes with hybrid tunnel junction layers,” IEEE J. Quantum Electron. 51(8), 3300505 (2015).
[Crossref]

Makarona, E.

I. Ozden, E. Makarona, A. V. Nurmikko, T. Takeuchi, and M. Krames, “A dual-wavelength indium gallium nitride quantum well light emitting diode,” Appl. Phys. Lett. 79(16), 2532–2534 (2001).
[Crossref]

Makimoto, T.

Y. Taniyasu, M. Kasu, and T. Makimoto, “An aluminium nitride light-emitting diode with a wavelength of 210 nanometres,” Nature 441(7091), 325–328 (2006).
[Crossref] [PubMed]

Morita, T.

M. Kaga, T. Morita, Y. Kuwano, K. Yamashita, K. Yagi, M. Iwaya, T. Takeuchi, S. Kamiyama, and I. Akasaki, “GaInN-based tunnel junctions in n–p–n light emitting diodes,” Jpn. J. Appl. Phys. 52(8S), 08JH06 (2013).
[Crossref]

Nagahama, S.

S. Nakamura, M. Senoh, N. Iwasa, and S. Nagahama, “High-brightness InGaN blue, green and yellow light-emitting diodes with quantum well structures,” Jpn. J. Appl. Phys. 34(Part 2, No. 7A), L797–L799 (1995).
[Crossref]

Nakamura, S.

S. Nakamura, M. Senoh, N. Iwasa, and S. Nagahama, “High-brightness InGaN blue, green and yellow light-emitting diodes with quantum well structures,” Jpn. J. Appl. Phys. 34(Part 2, No. 7A), L797–L799 (1995).
[Crossref]

Nath, D. N.

S. Krishnamoorthy, D. N. Nath, F. Akyol, P. S. Park, M. Esposto, and S. Rajan, “Polarization-engineered GaN/InGaN/GaN tunnel diodes,” Appl. Phys. Lett. 97(20), 203502 (2010).
[Crossref]

Nurmikko, A. V.

I. Ozden, E. Makarona, A. V. Nurmikko, T. Takeuchi, and M. Krames, “A dual-wavelength indium gallium nitride quantum well light emitting diode,” Appl. Phys. Lett. 79(16), 2532–2534 (2001).
[Crossref]

Ozden, I.

I. Ozden, E. Makarona, A. V. Nurmikko, T. Takeuchi, and M. Krames, “A dual-wavelength indium gallium nitride quantum well light emitting diode,” Appl. Phys. Lett. 79(16), 2532–2534 (2001).
[Crossref]

Park, P. S.

S. Krishnamoorthy, F. Akyol, P. S. Park, and S. Rajan, “Low resistance GaN/InGaN/GaN tunnel junctions,” Appl. Phys. Lett. 102(11), 113503 (2013).
[Crossref]

S. Krishnamoorthy, P. S. Park, and S. Rajan, “Demonstration of forward inter-band tunneling in GaN by polarization engineering,” Appl. Phys. Lett. 99(23), 233504 (2011).
[Crossref]

S. Krishnamoorthy, D. N. Nath, F. Akyol, P. S. Park, M. Esposto, and S. Rajan, “Polarization-engineered GaN/InGaN/GaN tunnel diodes,” Appl. Phys. Lett. 97(20), 203502 (2010).
[Crossref]

Piprek, J.

J. Piprek, “Origin of InGaN/GaN light-emitting diode efficiency improvements using tunnel-junction-cascaded active regions,” Appl. Phys. Lett. 104(5), 051118 (2014).
[Crossref]

J. Piprek, “Efficiency droop in nitride-based light-emitting diodes,” Phys. Status Solidi., A Appl. Mater. Sci. 207(10), 2217–2225 (2010).
[Crossref]

Rajan, S.

F. Akyol, S. Krishnamoorthy, Y. Zhang, and S. Rajan, “GaN-based three-junction cascaded light-emitting diode with low-resistance InGaN tunnel junctions,” Appl. Phys. Express 8(8), 082103 (2015).
[Crossref]

F. Akyol, S. Krishnamoorthy, and S. Rajan, “Tunneling-based carrier regeneration in cascaded GaN light emitting diodes to overcome efficiency droop,” Appl. Phys. Lett. 103(8), 081107 (2013).
[Crossref]

S. Krishnamoorthy, F. Akyol, P. S. Park, and S. Rajan, “Low resistance GaN/InGaN/GaN tunnel junctions,” Appl. Phys. Lett. 102(11), 113503 (2013).
[Crossref]

S. Krishnamoorthy, P. S. Park, and S. Rajan, “Demonstration of forward inter-band tunneling in GaN by polarization engineering,” Appl. Phys. Lett. 99(23), 233504 (2011).
[Crossref]

S. Krishnamoorthy, D. N. Nath, F. Akyol, P. S. Park, M. Esposto, and S. Rajan, “Polarization-engineered GaN/InGaN/GaN tunnel diodes,” Appl. Phys. Lett. 97(20), 203502 (2010).
[Crossref]

Schubert, E. F.

M. F. Schubert, S. Chhajed, J. K. Kim, E. F. Schubert, D. D. Koleske, M. H. Crawford, S. R. Lee, A. J. Fischer, G. Thaler, and M. A. Banas, “Effect of dislocation density on efficiency droop in GaInN/GaN/GaInN/GaN light-emitting diodes,” Appl. Phys. Lett. 91(23), 231114 (2007).
[Crossref]

Schubert, M. F.

M. F. Schubert, “Interband tunnel junctions for wurtzite III-nitride semiconductors based on heterointerface polarization charges,” Phys. Rev. B 81(3), 035303 (2010).
[Crossref]

M. F. Schubert, S. Chhajed, J. K. Kim, E. F. Schubert, D. D. Koleske, M. H. Crawford, S. R. Lee, A. J. Fischer, G. Thaler, and M. A. Banas, “Effect of dislocation density on efficiency droop in GaInN/GaN/GaInN/GaN light-emitting diodes,” Appl. Phys. Lett. 91(23), 231114 (2007).
[Crossref]

Senoh, M.

S. Nakamura, M. Senoh, N. Iwasa, and S. Nagahama, “High-brightness InGaN blue, green and yellow light-emitting diodes with quantum well structures,” Jpn. J. Appl. Phys. 34(Part 2, No. 7A), L797–L799 (1995).
[Crossref]

Shei, S.-C.

J.-K. Sheu, J.-M. Tsai, S.-C. Shei, W.-C. Lai, T.-C. Wen, C.-H. Kou, Y.-K. Su, S.-J. Chang, and G.-C. Chi, “Low-operation voltage of InGaN-GaN light-emitting diodes with Si-doped In0.3Ga 0.7N/GaN short-period superlattice tunneling contact layer,” IEEE Electron Device Lett. 22(10), 460–462 (2001).
[Crossref]

Sheu, J.-K.

Y.-H. Shih, J.-Y. Chang, J.-K. Sheu, Y.-K. Kuo, F.-M. Chen, M.-L. Lee, and W.-C. Lai, “Design of hole-blocking and electron-blocking layers in AlxGa1–xN-based UV light-emitting diodes,” IEEE Trans. Electron Dev. 63(3), 1141–1147 (2016).
[Crossref]

J.-K. Sheu, J.-M. Tsai, S.-C. Shei, W.-C. Lai, T.-C. Wen, C.-H. Kou, Y.-K. Su, S.-J. Chang, and G.-C. Chi, “Low-operation voltage of InGaN-GaN light-emitting diodes with Si-doped In0.3Ga 0.7N/GaN short-period superlattice tunneling contact layer,” IEEE Electron Device Lett. 22(10), 460–462 (2001).
[Crossref]

Shih, Y.-H.

Y.-H. Shih, J.-Y. Chang, J.-K. Sheu, Y.-K. Kuo, F.-M. Chen, M.-L. Lee, and W.-C. Lai, “Design of hole-blocking and electron-blocking layers in AlxGa1–xN-based UV light-emitting diodes,” IEEE Trans. Electron Dev. 63(3), 1141–1147 (2016).
[Crossref]

Simon, J.

J. Simon, Z. Zhang, K. Goodman, H. Xing, T. Kosel, P. Fay, and D. Jena, “Polarization-induced zener tunnel junctions in wide-band-gap heterostructures,” Phys. Rev. Lett. 103(2), 026801 (2009).
[Crossref] [PubMed]

Su, Y.-K.

J.-K. Sheu, J.-M. Tsai, S.-C. Shei, W.-C. Lai, T.-C. Wen, C.-H. Kou, Y.-K. Su, S.-J. Chang, and G.-C. Chi, “Low-operation voltage of InGaN-GaN light-emitting diodes with Si-doped In0.3Ga 0.7N/GaN short-period superlattice tunneling contact layer,” IEEE Electron Device Lett. 22(10), 460–462 (2001).
[Crossref]

Takasuka, D.

D. Takasuka, Y. Akatsuka, M. Ino, N. Koide, T. Takeuchi, M. Iwaya, S. Kamiyama, and I. Akasaki, “GaInN-based tunnel junctions with graded layers,” Appl. Phys. Express 9(8), 081005 (2016).
[Crossref]

Takeuchi, T.

D. Takasuka, Y. Akatsuka, M. Ino, N. Koide, T. Takeuchi, M. Iwaya, S. Kamiyama, and I. Akasaki, “GaInN-based tunnel junctions with graded layers,” Appl. Phys. Express 9(8), 081005 (2016).
[Crossref]

M. Kaga, T. Morita, Y. Kuwano, K. Yamashita, K. Yagi, M. Iwaya, T. Takeuchi, S. Kamiyama, and I. Akasaki, “GaInN-based tunnel junctions in n–p–n light emitting diodes,” Jpn. J. Appl. Phys. 52(8S), 08JH06 (2013).
[Crossref]

I. Ozden, E. Makarona, A. V. Nurmikko, T. Takeuchi, and M. Krames, “A dual-wavelength indium gallium nitride quantum well light emitting diode,” Appl. Phys. Lett. 79(16), 2532–2534 (2001).
[Crossref]

Taniyasu, Y.

Y. Taniyasu, M. Kasu, and T. Makimoto, “An aluminium nitride light-emitting diode with a wavelength of 210 nanometres,” Nature 441(7091), 325–328 (2006).
[Crossref] [PubMed]

Thaler, G.

M. F. Schubert, S. Chhajed, J. K. Kim, E. F. Schubert, D. D. Koleske, M. H. Crawford, S. R. Lee, A. J. Fischer, G. Thaler, and M. A. Banas, “Effect of dislocation density on efficiency droop in GaInN/GaN/GaInN/GaN light-emitting diodes,” Appl. Phys. Lett. 91(23), 231114 (2007).
[Crossref]

Tsai, J.-M.

J.-K. Sheu, J.-M. Tsai, S.-C. Shei, W.-C. Lai, T.-C. Wen, C.-H. Kou, Y.-K. Su, S.-J. Chang, and G.-C. Chi, “Low-operation voltage of InGaN-GaN light-emitting diodes with Si-doped In0.3Ga 0.7N/GaN short-period superlattice tunneling contact layer,” IEEE Electron Device Lett. 22(10), 460–462 (2001).
[Crossref]

Wen, T.-C.

J.-K. Sheu, J.-M. Tsai, S.-C. Shei, W.-C. Lai, T.-C. Wen, C.-H. Kou, Y.-K. Su, S.-J. Chang, and G.-C. Chi, “Low-operation voltage of InGaN-GaN light-emitting diodes with Si-doped In0.3Ga 0.7N/GaN short-period superlattice tunneling contact layer,” IEEE Electron Device Lett. 22(10), 460–462 (2001).
[Crossref]

Xing, H.

J. Simon, Z. Zhang, K. Goodman, H. Xing, T. Kosel, P. Fay, and D. Jena, “Polarization-induced zener tunnel junctions in wide-band-gap heterostructures,” Phys. Rev. Lett. 103(2), 026801 (2009).
[Crossref] [PubMed]

Yagi, K.

M. Kaga, T. Morita, Y. Kuwano, K. Yamashita, K. Yagi, M. Iwaya, T. Takeuchi, S. Kamiyama, and I. Akasaki, “GaInN-based tunnel junctions in n–p–n light emitting diodes,” Jpn. J. Appl. Phys. 52(8S), 08JH06 (2013).
[Crossref]

Yamashita, K.

M. Kaga, T. Morita, Y. Kuwano, K. Yamashita, K. Yagi, M. Iwaya, T. Takeuchi, S. Kamiyama, and I. Akasaki, “GaInN-based tunnel junctions in n–p–n light emitting diodes,” Jpn. J. Appl. Phys. 52(8S), 08JH06 (2013).
[Crossref]

Zhang, Y.

F. Akyol, S. Krishnamoorthy, Y. Zhang, and S. Rajan, “GaN-based three-junction cascaded light-emitting diode with low-resistance InGaN tunnel junctions,” Appl. Phys. Express 8(8), 082103 (2015).
[Crossref]

Zhang, Z.

J. Simon, Z. Zhang, K. Goodman, H. Xing, T. Kosel, P. Fay, and D. Jena, “Polarization-induced zener tunnel junctions in wide-band-gap heterostructures,” Phys. Rev. Lett. 103(2), 026801 (2009).
[Crossref] [PubMed]

Appl. Phys. Express (2)

F. Akyol, S. Krishnamoorthy, Y. Zhang, and S. Rajan, “GaN-based three-junction cascaded light-emitting diode with low-resistance InGaN tunnel junctions,” Appl. Phys. Express 8(8), 082103 (2015).
[Crossref]

D. Takasuka, Y. Akatsuka, M. Ino, N. Koide, T. Takeuchi, M. Iwaya, S. Kamiyama, and I. Akasaki, “GaInN-based tunnel junctions with graded layers,” Appl. Phys. Express 9(8), 081005 (2016).
[Crossref]

Appl. Phys. Lett. (7)

S. Krishnamoorthy, D. N. Nath, F. Akyol, P. S. Park, M. Esposto, and S. Rajan, “Polarization-engineered GaN/InGaN/GaN tunnel diodes,” Appl. Phys. Lett. 97(20), 203502 (2010).
[Crossref]

I. Ozden, E. Makarona, A. V. Nurmikko, T. Takeuchi, and M. Krames, “A dual-wavelength indium gallium nitride quantum well light emitting diode,” Appl. Phys. Lett. 79(16), 2532–2534 (2001).
[Crossref]

F. Akyol, S. Krishnamoorthy, and S. Rajan, “Tunneling-based carrier regeneration in cascaded GaN light emitting diodes to overcome efficiency droop,” Appl. Phys. Lett. 103(8), 081107 (2013).
[Crossref]

J. Piprek, “Origin of InGaN/GaN light-emitting diode efficiency improvements using tunnel-junction-cascaded active regions,” Appl. Phys. Lett. 104(5), 051118 (2014).
[Crossref]

S. Krishnamoorthy, P. S. Park, and S. Rajan, “Demonstration of forward inter-band tunneling in GaN by polarization engineering,” Appl. Phys. Lett. 99(23), 233504 (2011).
[Crossref]

S. Krishnamoorthy, F. Akyol, P. S. Park, and S. Rajan, “Low resistance GaN/InGaN/GaN tunnel junctions,” Appl. Phys. Lett. 102(11), 113503 (2013).
[Crossref]

M. F. Schubert, S. Chhajed, J. K. Kim, E. F. Schubert, D. D. Koleske, M. H. Crawford, S. R. Lee, A. J. Fischer, G. Thaler, and M. A. Banas, “Effect of dislocation density on efficiency droop in GaInN/GaN/GaInN/GaN light-emitting diodes,” Appl. Phys. Lett. 91(23), 231114 (2007).
[Crossref]

IEEE Electron Device Lett. (1)

J.-K. Sheu, J.-M. Tsai, S.-C. Shei, W.-C. Lai, T.-C. Wen, C.-H. Kou, Y.-K. Su, S.-J. Chang, and G.-C. Chi, “Low-operation voltage of InGaN-GaN light-emitting diodes with Si-doped In0.3Ga 0.7N/GaN short-period superlattice tunneling contact layer,” IEEE Electron Device Lett. 22(10), 460–462 (2001).
[Crossref]

IEEE J. Quantum Electron. (1)

S.-J. Chang, W.-H. Lin, and W.-S. Chen, “Cascaded GaN light-emitting diodes with hybrid tunnel junction layers,” IEEE J. Quantum Electron. 51(8), 3300505 (2015).
[Crossref]

IEEE Trans. Electron Dev. (1)

Y.-H. Shih, J.-Y. Chang, J.-K. Sheu, Y.-K. Kuo, F.-M. Chen, M.-L. Lee, and W.-C. Lai, “Design of hole-blocking and electron-blocking layers in AlxGa1–xN-based UV light-emitting diodes,” IEEE Trans. Electron Dev. 63(3), 1141–1147 (2016).
[Crossref]

Jpn. J. Appl. Phys. (2)

M. Kaga, T. Morita, Y. Kuwano, K. Yamashita, K. Yagi, M. Iwaya, T. Takeuchi, S. Kamiyama, and I. Akasaki, “GaInN-based tunnel junctions in n–p–n light emitting diodes,” Jpn. J. Appl. Phys. 52(8S), 08JH06 (2013).
[Crossref]

S. Nakamura, M. Senoh, N. Iwasa, and S. Nagahama, “High-brightness InGaN blue, green and yellow light-emitting diodes with quantum well structures,” Jpn. J. Appl. Phys. 34(Part 2, No. 7A), L797–L799 (1995).
[Crossref]

Nature (1)

Y. Taniyasu, M. Kasu, and T. Makimoto, “An aluminium nitride light-emitting diode with a wavelength of 210 nanometres,” Nature 441(7091), 325–328 (2006).
[Crossref] [PubMed]

Phys. Rev. B (1)

M. F. Schubert, “Interband tunnel junctions for wurtzite III-nitride semiconductors based on heterointerface polarization charges,” Phys. Rev. B 81(3), 035303 (2010).
[Crossref]

Phys. Rev. Lett. (1)

J. Simon, Z. Zhang, K. Goodman, H. Xing, T. Kosel, P. Fay, and D. Jena, “Polarization-induced zener tunnel junctions in wide-band-gap heterostructures,” Phys. Rev. Lett. 103(2), 026801 (2009).
[Crossref] [PubMed]

Phys. Status Solidi., A Appl. Mater. Sci. (1)

J. Piprek, “Efficiency droop in nitride-based light-emitting diodes,” Phys. Status Solidi., A Appl. Mater. Sci. 207(10), 2217–2225 (2010).
[Crossref]

Proc. SPIE (1)

Y.-K. Kuo and J.-Y. Chang, “Investigation of degraded efficiency in blue InGaN multiple-quantum well light-emitting diodes,” Proc. SPIE 9357, 93571L (2015).
[Crossref]

Other (3)

J. Piprek, Nitride Semiconductor Devices: Principles and Simulation (Wiley-VCH verlag, 2007), pp. 423–445.

E. F. Schubert, Light-Emitting Diodes (Cambridge University, 2006), pp 137–141.

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Figures (6)

Fig. 1
Fig. 1 Schematic structures of (a) TJLED-1 and (b) TJLED-2.
Fig. 2
Fig. 2 (a) L-I and (b) I-V characteristics as a function of injection current of TJLED-1 and TJLED-2.
Fig. 3
Fig. 3 Energy band diagrams and electric fields of (a) (c) TJ-1 and (b) (d) TJ-2 at equilibrium.
Fig. 4
Fig. 4 Simulated electrical characteristics of TJ-1 and TJ-2 in the reversed bias regime.
Fig. 5
Fig. 5 Schematic device structures and light-emission images of (a) SLED, (b) TLED, and (c) TJLED chips.
Fig. 6
Fig. 6 (a) L-I, (b) I-V, (c) EQE, WPE (inset), and (d) EL spectral characteristics of SLED, TLED, and TJLED.

Tables (1)

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Table 1 Layer composition, thickness d (nm), and doping concentration Ndop (1/cm3) of the TJ.

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