Enhanced performance of AlGaN-based deep ultraviolet LEDs with a combined superlattice and multi-gradient electron blocking layer

Abstract

Traditional AlGaN electron blocking layer (EBL) has significant limitations in reducing electron leakage and enhancing electron injection, especially in high-Al-content environments. This study presents an EBL that combines superlattice (SL) and multi-gradient structures, aiming to enhance the performance of deep ultraviolet (DUV) light-emitting diodes (LEDs). Simulations were performed using the semiconductor device advanced physics model (APSYS) software, and comparisons were made with conventional high-Al content AlGaN EBL and SL EBL. The results indicate that the combination of SL and multi-gradient EBL significantly increases the electron barrier height, suppresses electron leakage, and enhances hole injection efficiency, leading to a 42.4% increase in internal quantum efficiency (IQE) and a notable 341.6% increase in output power compared to reference LED structure. Simultaneously, significant improvements were observed in the radiative recombination rate and spontaneous emission rate, offering new insights for the design of high-performance devices in ultraviolet applications.

Keywords

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References

[1] Xu R, Kang Q, Zhang Y, et al. Research progress of AlGaN-based deep ultraviolet light-emitting diodes. Micromachines, 2023, 144844. J]

[2] Lang J, Xu F, Wang J, et al. Progress in performance of AlGaN-based ultraviolet light emitting diodes. Advanced electronic materials, 2025, 1112300840. J]

[3] Bhattarai T, Ebong A, Raja M Y A. A review of light-emitting diodes and ultraviolet light-emitting diodes and their applications. Photonics, 2024, 116491. J]

[4] Mondal R K, Adhikari S, Chatterjee V, et al. Recent advances and challenges in AlGaN-based ultra-violet light emitting diode technologies. Materials research bulletin, 2021, 140: 111258. J]

[5] LIU C, OOI Y K, ISLAM S M, et al. 234 nm and 246 nm AlN-Delta-GaN quantum well deep ultraviolet light-emitting diodes[J]. Applied physics letters, 2018, 112(1).

[6] Xing Z, Zhang A, Qu Y, et al. Increasing the hole energy by the p-type dual polarization for high internal quantum efficiency of 237 nm-band deep ultraviolet light-emitting diodes. Optical engineering, 2024, 632027103. J]

[7] Gao Y, Tian W, Qi Y, et al. Interfacial polarization charge engineering with co-designed LQB and EBL for enhanced EQE of AlGaN DUV LEDs. Semiconductor science and technology, 2024, 401015021. J]

[8] Wang L, He W, Zheng T, et al. Enhanced optical performance of AlGaN-based deep-ultraviolet light-emitting diode with m-shaped hole blocking layer and w-shaped electron blocking layer. Superlattices and microstructures, 2019, 133: 106188. J]

[9] Shi H, Gu H, Li J, et al. Performance improvements of AlGaN-based deep-ultraviolet light-emitting diodes with specifically designed irregular sawtooth hole and electron blocking layers. Optics communications, 2019, 441: 149-154. J]

[10] Fan X, Sun H, Li X, et al. Efficiency improvements in AlGaN-based deep ultraviolet light-emitting diodes using inverted-V-shaped graded Al composition electron blocking layer. Superlattices and microstructures, 2015, 88: 467-173. J]

[11] Zhang Z H, Huang Chen S W, Chu C, et al. Nearly efficiency-droop-free AlGaN-based ultraviolet light-emitting diodes with a specifically designed superlattice p-type electron blocking layer for high Mg doping efficiency. Nanoscale research letters, 2018, 13: 1-7[J]

[12] Lv Q, Cao Y, Li R, et al. Performance improvement of AlGaN-based deep-ultraviolet light-emitting diodes with multigradient electron blocking layer and triangular last quantum barrier. Physica status solidi (a), 2023, 220132300192. J]

[13] Ye W T, Cheng Z J, Ren Z Y, et al. Efficient carrier confinement in AlGaN-based deep-ultraviolet light-emitting diodes with a composition-graded electron-blocking layer. Physica status solidi (a), 2023, 22022200674. J]

[14] LANG J, XU F J, WANG J M, et al. On the integrated p-type region free of electron blocking layer for AlGaN-based deep-ultraviolet light emitting diodes[J]. Applied physics letters, 2023, 123(26).

[15] Xu Y, Yin M, Sang X, et al. Optimization of AlGaN-based deep UV LED performance by p-AlInGaN/AlInGaN graded superlattice electron blocking layer. Applied optics, 2023, 622260256030. J]

[16] LI Z M, LI Y Y, RU G P. Simulation of quantum cascade lasers[J]. Journal of applied physics, 2011, 110(9).

[17] Varshni Y P. Temperature dependence of the energy gap in semiconductors. Physica, 1967, 341149154. J]

[18] Vurgaftman I, Meyer J Á, Ram-Mohan L R. Band parameters for III–V compound semiconductors and their alloys. Journal of applied physics, 2001, 891158155875. J]

[19] Yin X, Zhao S. Improving charge carrier transport properties in AlGaN deep ultraviolet light emitters using Al-content engineered superlattice electron blocking layer. IEEE journal of quantum electronics, 2023, 59116. J]

[20] Fiorentini V, Bernardini F, Ambacher O. Evidence for nonlinear macroscopic polarization in III–V nitride alloy heterostructures. Applied physics letters, 2002, 80712041206. J]

[21] Chang J Y, Liou B T, Huang M F, et al. High-efficiency deep-ultraviolet light-emitting diodes with efficient carrier confinement and high light extraction. IEEE transactions on electron devices, 2019, 662976982. J]

[22] Sang X, Xu Y, Yin M, et al. InGaN multiple quantum well based light-emitting diodes with indium composition gradient InGaN quantum barriers. Optoelectronics letters, 2024, 2028993. J]

[23] Vurgaftman I, Meyer J N. Band parameters for nitrogen-containing semiconductors. Journal of applied physics, 2003, 94636753696. J]

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