pπBn型Ⅱ类超晶格暗电流特性研究  

Study on dark current characteristics of pπBn type-II superlattices

作　　者：闫勇 王晓华 周朋[1] 刘铭[1] YAN Yong;WANG Xiao-hua;ZHOU Peng;LIU Ming(The 11th Institute of CETC,Beijing 100015,China)

机构地区：[1]中国电子科技集团公司第十一研究所,北京100015

出　　处：《激光与红外》2024年第5期750-757,共8页Laser & Infrared

摘　　要：InAs/GaSbⅡ类超晶格(T2SL)红外探测器由于具有宽光谱探测能力、较好的材料均匀性、可以抑制载流子俄歇复合率和灵活的能带设计等优点,在长波红外探测领域具有很大的优势。但由于暗电流较大,其性能并未达到理论预测。pπBn结构是在超晶格材料的吸收层和接触层之间增加单极势垒,以抑制G-R暗电流和隧穿暗电流。本文分别从理论上研究了吸收层、势垒层和接触层的超晶格能带结构。模拟了pπBn结构的InAs/GaSb T2SL,研究了其吸收层掺杂浓度、势垒层掺杂浓度和势垒厚度对器件暗电流的影响。通过优化吸收层掺杂浓度、势垒层厚度和掺杂浓度,得到暗电流密度为8.35×10^(-7)A/cm^(-2)的pπBn结构InAs/GaSb T2SL,与优化前的结构相比,暗电流降低了一个数量级。研究过程不仅为pπBn结构的InAs/GaSb T2SL器件的低暗电流设计提供了指导,而且为优化超晶格器件的暗电流提供了一种系统的方法。InAs/GaSb type-II superlattice(T2SL)infrared detectors have great advantages in the field of long-wave infrared detection due to their broad-band detection capability,high material uniformity,suppressed Auger recombination rates and flexible energy band design.However,the performances do not reach the theoretical prediction due to the large dark current.The pπBn structure is designed to add a monopole barrier between the absorption layer and the contact layer of the detector to suppress the G-R dark current and tunneling dark current.In this paper,the superlattice band structure of absorption layer,barrier layer and contact layer are studied theoretically separately.This study simulates a InAs/GaSb T2SL with pπBn structure and study its doping concentration of the absorption layer,the doping concentration of the barrier layer and the thickness of the barrier layer to reduce the dark current.Through optimizing the doping concentration of the absorption layer,the thickness and the doping concentration of the barrier layer,the pπBn structure InAs/GaSb T2SL with dark current density of 8.35×10^(-7)A/cm^(2)is obtained,which reduces the dark current by one order of magnitude as compared with that of the structure before optimization.The research process not only provides guidance for designing the low dark current with pπBn structure device,but also develops a systematic method to optimize the dark current of superlattice device.

关 键 词：INAS/GASB 能带结构 暗电流密度 

分 类 号：TN213[电子电信—物理电子学] O436[机械工程—光学工程]