量子垒高度对深紫外LED调制带宽的影响  

Effect of Barrier Height on Modulation Characteristics of AlGaN-based Deep Ultraviolet Light-emitting Diodes

作　　者：郭亮 郭亚楠[1,2] 羊建坤 闫建昌[1,2] 王军喜 魏同波[1,2] GUO Liang;GUO Ya-nan;YANG Jian-kun;YAN Jian-chang;WANG Jun-xi;WEI Tong-bo(Research and Development Center for Semiconductor Lighting Technology, Institute of Semiconductors,Chinese Academy of Sciences, Beijing 100083, China;Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China)

机构地区：[1]中国科学院半导体研究所半导体照明研发中心,北京100083 [2]中国科学院大学材料与光电研究中心,北京100049

出　　处：《发光学报》2022年第1期1-7,共7页Chinese Journal of Luminescence

基　　金：国家重点研发计划(2017YFB0404104);国家自然科学基金(61974139);北京自然科学基金(4182063)资助项目。

摘　　要：AlGaN基深紫外LED由于具有高调制带宽和小芯片尺寸,在紫外光通信领域受到越来越多的关注。本研究通过改变生长AlGaN量子垒层的Al源流量,生长了三种具有不同量子垒高度的深紫外LED,研究了量子垒高度对深紫外LED光电特性和调制特性的影响。研究发现,随着量子垒高度的增加,深紫外LED的光功率出现先增加后减小的趋势,量子垒中Al组分为55%的深紫外LED的光功率相比50%和60%的深紫外LED提升了近一倍。载流子寿命则出现先减小后增大的趋势,且发光峰峰值波长逐渐蓝移。APSYS模拟表明,随着量子垒高度增加,量子垒对载流子的束缚能力增强,电子空穴波函数空间重叠增加,载流子浓度和辐射复合速率增加;但进一步增加量子垒高度又会由于电子泄露,空穴浓度降低,从而辐射复合速率降低。量子垒中Al组分为55%的深紫外LED的-3 dB带宽达到94.4 MHz,高于量子垒Al组分为50%和60%的深紫外LED。AlGaN-based deep ultraviolet LED has attracted more and more attention in ultraviolet communication due to its high modulation bandwidth and small chip size.In this study,AlGaN-based deep ultraviolet LEDs with varied Al composition of 50%,55%,60%in quantum barriers are fabricated.The effect of barrier height on the photoelectric and modulation characteristics of deep ultraviolet LEDs is studied.It is found that the optical power and external quantum efficiency(EQE)of the deep ultraviolet LED increase first and then decreased,and carrier lifetime decreases first and then increases as the quantum barrier height increases.The peak wavelength of the spectra shows a blue-shift.APSYS simulation revealed that the spacial overlap between the wave function of electron and hole is enhanced as Al composition increases.But further increase on barrier height will lead to current leakage which reduces the radiation recombination rate and carrier density in multi-quantum well layer.The-3 dB bandwidth of deep ultraviolet LED with 55%Al composition in quantum barrier is measured to be 94.4 MHz,higher than those with 50%and 60%Al composition in quantum barrier.

关 键 词：紫外光通信 深紫外发光二极管 多量子阱层 调制带宽 发光功率 

分 类 号：TN383.1[电子电信—物理电子学] TN929.12