量子阱渐变层材料及结构对GaN基LED性能的影响  

Effect of Material and Structure of Quantum Well Gradient Layer on Performance of GaN-Based LED

作　　者：王进军[1] 杨艳莹 白斌辉 徐晨昱 Wang Jinjun;Yang Yanying;Bai Binhui;Xu Chenyu(School of Electronic Information and Artificial Intelligence,Shaanxi University of Science&Technology,Xi'an 710021,Shaanxi,China)

机构地区：[1]陕西科技大学电子信息与人工智能学院,陕西西安710021

出　　处：《光学学报》2023年第4期157-165,共9页Acta Optica Sinica

基　　金：2018年陕西省教育厅科研计划专项项目(18JK0103)。

摘　　要：In组分渐变InGaN/GaN量子阱结构可以有效解决晶格失配所带来的LED发光效率降低的问题。采用Silvaco软件建立了In组分渐变量子阱结构数值计算模型,研究了量子阱中渐变层In组分及渐变层厚度对极化电荷密度、载流子浓度及LED功率谱密度的影响。研究结果表明:随着渐变层中In组分的增加,载流子浓度以及极化电荷密度都在增大,但极化电荷密度增幅较小,峰值功率谱密度随着In组分增加的增长幅度逐渐减小;功率谱密度随着渐变层顶层厚度的增加先增大后减小,渐变层非顶层厚度不均匀时的功率谱密度比均匀时的功率谱密度小。Objective The active region of conventional GaN-based LEDs mostly adopts the InGaN/GaN quantum well structure.However,due to the large size difference between In and Ga atoms,there is a large lattice mismatch between InN and GaN,which leads to the generation of polarized electric field and tilted energy band.On the one hand,some holes escape,which results in decreased radiation recombination efficiency,thus inducing the quantum-confined Stark effect.On the other hand,since the bond energy of In—N is smaller than that of Ga—N,it is easy to form in gap atoms,thereby introducing crystal defects and reducing the internal quantum efficiency.The In composition gradient InGaN/GaN quantum well structure can solve the LED luminous efficiency reduction caused by lattice mismatch.However,the effects of In composition and thickness of the gradient layer on polarization charge concentration,carrier concentration,and LED power spectral density are still unclear.It is particularly important to study the effects of the material and structure of the quantum well gradient layer on the performance of GaN-based LED for improving the efficiency of GaN-based LEDs.Methods The numerical calculation model of GaN-based LED with In component gradient quantum well structure is built by Silvaco TCAD software.Based on the composite model,carrier statistical model,carrier transport model,selfconsistent Schrodinger Poisson equation,and spontaneous polarization and piezoelectric polarization model of the built-in electric field,the effects of In component in the gradient layer and thickness of the top layer of the gradient layer on the polarization charge concentration,carrier concentration,and power spectral density are simulated and calculated.Firstly,the thickness of the gradient layer keeps constant,and the In composition of the gradient layer is changed.The changes of polarization charge concentration,carrier concentration,and power spectral density with In composition are calculated and analyzed.Secondly,the influence of the In composi

关 键 词：材料 GAN基LED 量子阱 渐变层 功率谱密度 

分 类 号：TN312.8[电子电信—物理电子学]