Design of long‐wavelength infrared InAs/InAsSb type‐II superlattice avalanche photodetector with stepped grading layer  

作　　者：Keming Cheng Kai Shen Chuang Li Daqian Guo Hao Wang Jiang Wu 

机构地区：[1]Institute of Fundamental and Frontier Sciences,University of Electronic Science and Technology of China,Chengdu,China [2]Intelligent Terminal Key Laboratory of SiChuan Province,Yibin Institute of UESTC,Yibin,China [3]Division of Electrical Engineering,Department of Engineering,University of Cambridge,Cambridge,UK [4]State Key Laboratory of Electronic Thin Films and Integrated Devices,University of Electronic Science and Technology of China,Chengdu,China

出　　处：《Electron》2024年第4期10-18,共9页电子(英文)

基　　金：Fundamental Research Funds for the Central Universities,Grant/Award Number:ZYGX2019Z018;National Natural Science Foundation of China,Grant/Award Number:61974014;Innovation Group Project of Sichuan Province,Grant/Award Number:20CXTD0090。

摘　　要：Weak response in long‐wavelength infrared(LWIR)detection has long been a perennial concern,significantly limiting the reliability of appli-cations.Avalanche photodetectors(APDs)offer excellent responsivity but are plagued by high dark current during the multiplication process.Here,we propose a high‐performance type‐II superlattices(T2SLs)LWIR APD to address these issues.The low Auger recombination rate of the InAs/InAsSb T2SLs absorption layer is exploited to reduce the dark current initially.AlAsSb with a low k value is employed as the multiplication layer to suppress device noise while maintaining sufficient gain.To facilitate carrier transport,the conduction band discontinuity is opti-mized by inserting an InAs/AlSb T2SLs stepped grading layer between the absorption and multiplication layers.As a result,the device exhibits excellent photoresponse at 8.4μm at 100 K and maintains a low dark current density of 5.4810^(-2) A/cm^(2).Specifically,it achieves a maximum gain of 366,a responsivity of 650 A/W,and a quantum efficiency of 26.28%under breakdown voltage.This design offers a promising solution for the advancement of LWIR detection.

关 键 词：AlAsSb avalanche photodetector InAs/InAsSb type‐II superlattice 

分 类 号：TN2[电子电信—物理电子学]