This study considered the design of an efficient, high brightness polar InGaN/GaN light emitting diode （LED） structure with A1GaN capping layer for green light emission. The deposition of high In （〉 15%） composit...This study considered the design of an efficient, high brightness polar InGaN/GaN light emitting diode （LED） structure with A1GaN capping layer for green light emission. The deposition of high In （〉 15%） composition within InGaN quantum well （QW） has limitations when providing intense green light. To design an effective model for a highly efficient InGaN green LEDs, this study considered the compositions of indium and aluminum for InxGal xN QW and AlyGal yN cap layers, along with different layer thicknesses of well, barrier and cap. These structural properties significantly affect different properties. For example, these properties affect electric fields of layers, polarization, overall elastic stress energy and lattice parameter of the structure, emission wavelength, and intensity of the emitted light. Three models with different composition and layer thicknesses are simulated and analyzed to obtain green light with in-plane equilibrium lattice parameter close to GaN （3.189 A ） with the highest oscillator strength values. A structure model is obtained with an oscillator strength value of 1.18 × 10-1 and least in-plane equilibrium lattice constant of 3.218 A. This emitter can emit at a wavelength of 540 nm, which is the expected design for the fabrication of highly efficient, bright green LEDs.展开更多
A strain-compensated InGaN quantum well（QW） active region employing a tensile AlGaN barrier is analyzed.Its spectral stability and efficiency droop for a dual-blue light-emitting diode（LED） are improved compared w...A strain-compensated InGaN quantum well（QW） active region employing a tensile AlGaN barrier is analyzed.Its spectral stability and efficiency droop for a dual-blue light-emitting diode（LED） are improved compared with those of the conventional InGaN/GaN QW dual-blue LEDs based on a stacking structure of two In0.18Ga0.82N/GaN QWs and two In0.12Ga0.88N/GaN QWs on the same sapphire substrate.It is found that the optimal performance is achieved when the Al composition of the strain-compensated AlGaN layer is 0.12 in blue QW and 0.21 in blue-violet QW.The improvement performance can be attributed to the strain-compensated InGaN-AlGaN/GaN QW,which can provide a better carrier confinement and effectively reduce leakage current.展开更多
In this paper, we theoretically study the effects of doping concentration ND and an external electric field on the intersubband transitions in InxAl（l-x）N/InyGa（l-y）N single quantum well by solving the Schrodinger...In this paper, we theoretically study the effects of doping concentration ND and an external electric field on the intersubband transitions in InxAl（l-x）N/InyGa（l-y）N single quantum well by solving the Schrodinger and Poisson equations self-consistently. Obtained results including transition energies, the band structure, and the optical absorption have been discussed. The lowest three intersubband transitions （E2 -El）, （E3 -El）, and （E3 -E2） are calculated as functions of doping concentration ND. By increasing the doping concentration ND, the depletion effect can be reduced, and the ionized electrons will compensate the internal electric field which results from the spontaneous polarization. Our results show that an optimum concentration ND exists for which the transition 0.8 eV （1.55 μm） is carried out. Finally, the dependence of the optical absorption α13（ω） on the external electric field and doping concentration is studied. The maximum of the optical absorption can be red-shifted or blue-shifted through varying the doping concentration and the external electric field. The obtained results can be used for designing optical fiber telecommunications operating at 1.55 μm.展开更多
In this study, the influence of multiple interruptions with trimethylindium(TMIn)-treatment in InGaN/GaN multiple quantum wells(MQWs) on green light-emitting diode(LED) is investigated. A comparison of conventional LE...In this study, the influence of multiple interruptions with trimethylindium(TMIn)-treatment in InGaN/GaN multiple quantum wells(MQWs) on green light-emitting diode(LED) is investigated. A comparison of conventional LEDs with the one fabricated with our method shows that the latter has better optical properties. Photoluminescence(PL) full-width at half maximum(FWHM) is reduced, light output power is much higher and the blue shift of electroluminescence(EL) dominant wavelength becomes smaller with current increasing. These improvements should be attributed to the reduced interface roughness of MQW and more uniformity of indium distribution in MQWs by the interruptions with TMIn-treatment.展开更多
采用数值分析方法进行模拟分析In Ga N/Ga N混合多量子阱中移去p-Al Ga N电子阻挡层对Ga N基双蓝光波长发光二极管(LED)性能的影响。结果发现,与传统的具有p-Al Ga N电子阻挡层的双蓝光波长LED相比,移去电子阻挡层能有效地改善电子和空...采用数值分析方法进行模拟分析In Ga N/Ga N混合多量子阱中移去p-Al Ga N电子阻挡层对Ga N基双蓝光波长发光二极管(LED)性能的影响。结果发现,与传统的具有p-Al Ga N电子阻挡层的双蓝光波长LED相比,移去电子阻挡层能有效地改善电子和空穴在混合多量子阱活性层中的分布均匀性,实现电子空穴在各个量子阱中的均衡辐射。在小电流驱动时,移去电子阻挡层器件的发光功率要明显优于具有电子阻挡层的器件;而在大电流驱动时,电子阻挡层能有效地减少电子溢流,改善器件的发光效率。展开更多
基金National Natural Science Foundation of China(No.62204127)the Natural Science Foundation of Jiangsu Province(No.BK20215093)State Key Laboratory of Luminescence and Applications(No.SKLA‒2021‒04)。
文摘This study considered the design of an efficient, high brightness polar InGaN/GaN light emitting diode （LED） structure with A1GaN capping layer for green light emission. The deposition of high In （〉 15%） composition within InGaN quantum well （QW） has limitations when providing intense green light. To design an effective model for a highly efficient InGaN green LEDs, this study considered the compositions of indium and aluminum for InxGal xN QW and AlyGal yN cap layers, along with different layer thicknesses of well, barrier and cap. These structural properties significantly affect different properties. For example, these properties affect electric fields of layers, polarization, overall elastic stress energy and lattice parameter of the structure, emission wavelength, and intensity of the emitted light. Three models with different composition and layer thicknesses are simulated and analyzed to obtain green light with in-plane equilibrium lattice parameter close to GaN （3.189 A ） with the highest oscillator strength values. A structure model is obtained with an oscillator strength value of 1.18 × 10-1 and least in-plane equilibrium lattice constant of 3.218 A. This emitter can emit at a wavelength of 540 nm, which is the expected design for the fabrication of highly efficient, bright green LEDs.
基金Project supported by the National Natural Science Foundation of China (Grant No. U1174001)the Ministry of Education Scientific Research Foundation for Returned Scholars,China (Grant No. 20091001)+1 种基金the Scientific and Technological Plan of Guangzhou City,China (Grant No. 2010U1-D00131)the Natural Science Foundation of Guangdong Province,China (Grant No. S2011010003400)
文摘A strain-compensated InGaN quantum well（QW） active region employing a tensile AlGaN barrier is analyzed.Its spectral stability and efficiency droop for a dual-blue light-emitting diode（LED） are improved compared with those of the conventional InGaN/GaN QW dual-blue LEDs based on a stacking structure of two In0.18Ga0.82N/GaN QWs and two In0.12Ga0.88N/GaN QWs on the same sapphire substrate.It is found that the optimal performance is achieved when the Al composition of the strain-compensated AlGaN layer is 0.12 in blue QW and 0.21 in blue-violet QW.The improvement performance can be attributed to the strain-compensated InGaN-AlGaN/GaN QW,which can provide a better carrier confinement and effectively reduce leakage current.
文摘In this paper, we theoretically study the effects of doping concentration ND and an external electric field on the intersubband transitions in InxAl（l-x）N/InyGa（l-y）N single quantum well by solving the Schrodinger and Poisson equations self-consistently. Obtained results including transition energies, the band structure, and the optical absorption have been discussed. The lowest three intersubband transitions （E2 -El）, （E3 -El）, and （E3 -E2） are calculated as functions of doping concentration ND. By increasing the doping concentration ND, the depletion effect can be reduced, and the ionized electrons will compensate the internal electric field which results from the spontaneous polarization. Our results show that an optimum concentration ND exists for which the transition 0.8 eV （1.55 μm） is carried out. Finally, the dependence of the optical absorption α13（ω） on the external electric field and doping concentration is studied. The maximum of the optical absorption can be red-shifted or blue-shifted through varying the doping concentration and the external electric field. The obtained results can be used for designing optical fiber telecommunications operating at 1.55 μm.
基金supported by the National Natural Science Foundation of China(Grant Nos.11204360 and 61210014)the Science and Technology Planning Projects of Guangdong Province,China(Grant Nos.2014B050505020,2015B010114007,and 2014B090904045)+2 种基金the Research Fund for the Doctoral Program of Higher Education of China(Grant No.20134407110008)the Guangzhou Municipal Science and Technology Project of Guangdong Province,China(Grant No.2016201604030027)the Zhongshan Science and Technology Project of Guangdong Province,China(Grant No.2013B3FC0003)
文摘In this study, the influence of multiple interruptions with trimethylindium(TMIn)-treatment in InGaN/GaN multiple quantum wells(MQWs) on green light-emitting diode(LED) is investigated. A comparison of conventional LEDs with the one fabricated with our method shows that the latter has better optical properties. Photoluminescence(PL) full-width at half maximum(FWHM) is reduced, light output power is much higher and the blue shift of electroluminescence(EL) dominant wavelength becomes smaller with current increasing. These improvements should be attributed to the reduced interface roughness of MQW and more uniformity of indium distribution in MQWs by the interruptions with TMIn-treatment.
文摘采用数值分析方法进行模拟分析In Ga N/Ga N混合多量子阱中移去p-Al Ga N电子阻挡层对Ga N基双蓝光波长发光二极管(LED)性能的影响。结果发现,与传统的具有p-Al Ga N电子阻挡层的双蓝光波长LED相比,移去电子阻挡层能有效地改善电子和空穴在混合多量子阱活性层中的分布均匀性,实现电子空穴在各个量子阱中的均衡辐射。在小电流驱动时,移去电子阻挡层器件的发光功率要明显优于具有电子阻挡层的器件;而在大电流驱动时,电子阻挡层能有效地减少电子溢流,改善器件的发光效率。
