In this study, the efficiency droop of an InGaN light-emitting diode （LED） is reduced slgnlncanUy oy using a p-AlGaN/GaN superlattice last quantum barrier. The reduction in efficiency droop is mainly caused by the d...In this study, the efficiency droop of an InGaN light-emitting diode （LED） is reduced slgnlncanUy oy using a p-AlGaN/GaN superlattice last quantum barrier. The reduction in efficiency droop is mainly caused by the decrease of electron current leakage and the increase of hole injection efficiency, which is revealed by investigating the light currents, internal quantum efficiencies, energy band diagrams, carrier concentrations, carrier current densities, and radiative recombination efficiencies of three LED structures with the advanced physical model of semiconductor device （APSYS）.展开更多
In GaN-based green light-emitting diodes（LEDs） with and without Mg-preflow before the growth of p-Al GaN electron blocking layer（EBL） are investigated experimentally.A higher Mg doping concentration is achieved in...In GaN-based green light-emitting diodes（LEDs） with and without Mg-preflow before the growth of p-Al GaN electron blocking layer（EBL） are investigated experimentally.A higher Mg doping concentration is achieved in the EBL after Mg-preflow treatment,effectively alleviating the commonly observed efficiency collapse and electrons overflowing at cryogenic temperatures.However,unexpected decline in quantum efficiency is observed after Mg-preflow treatment at room temperature.Our conclusions are drawn such that the efficiency decline is probably the result of different emission positions.Higher Mg doping concentration in the EBL after Mg-preflow treatment will make it easier for a hole to be injected into multiple quantum wells with emission closer to pGaN side through the（8-plane rather than the V-shape pits,which is not favorable to luminous efficiency due to the preferred occurrence of accumulated strain relaxation and structural defects in upper QWs closer to p-GaN.Within this framework,apparently disparate experimental observations regarding electroluminescence properties,in this work,are well reconciled.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.61176043)the Special Funds for Provincial Strategic and Emerging Industries Projects of Guangdong Province,China(Grant Nos.2010A081002005,2011A081301003,and 2012A080304016)+2 种基金the First Phase of Construction of Guangdong Research Institute of Semiconductor Lighting Industrial Technology,China(Grant No.2010A081001001)the High Efficiency LED Epitaxy and Chip Structure and Key Technology for Industrialization,China(Grant No.2012A080302002)the Youth Funding of South China Normal University(Grant No.2012KJ018)
文摘In this study, the efficiency droop of an InGaN light-emitting diode （LED） is reduced slgnlncanUy oy using a p-AlGaN/GaN superlattice last quantum barrier. The reduction in efficiency droop is mainly caused by the decrease of electron current leakage and the increase of hole injection efficiency, which is revealed by investigating the light currents, internal quantum efficiencies, energy band diagrams, carrier concentrations, carrier current densities, and radiative recombination efficiencies of three LED structures with the advanced physical model of semiconductor device （APSYS）.
基金Supported by the National Key R&D Program of China under Grant Nos 2016YFB0400600 and 2016YFB0400601the State Key Program of the National Natural Science of China under Grant No 61334001+2 种基金the Key R&D Program of Jiangxi Province under Grant No 20165ABC28007the Natural Science Foundation of Jiangxi Province under Grant No 20151BAB207053the National Natural Science Foundation of China under Grant No 21405076
文摘In GaN-based green light-emitting diodes（LEDs） with and without Mg-preflow before the growth of p-Al GaN electron blocking layer（EBL） are investigated experimentally.A higher Mg doping concentration is achieved in the EBL after Mg-preflow treatment,effectively alleviating the commonly observed efficiency collapse and electrons overflowing at cryogenic temperatures.However,unexpected decline in quantum efficiency is observed after Mg-preflow treatment at room temperature.Our conclusions are drawn such that the efficiency decline is probably the result of different emission positions.Higher Mg doping concentration in the EBL after Mg-preflow treatment will make it easier for a hole to be injected into multiple quantum wells with emission closer to pGaN side through the（8-plane rather than the V-shape pits,which is not favorable to luminous efficiency due to the preferred occurrence of accumulated strain relaxation and structural defects in upper QWs closer to p-GaN.Within this framework,apparently disparate experimental observations regarding electroluminescence properties,in this work,are well reconciled.
