高量子效率中波InAs/GaSb Ⅱ类超晶格探测器分子束外延生长及特性

Molecular beam epitaxy growth and characteristics of the high quantum efficiency InAs/GaSb type-Ⅱ superlattices MWIR detector

基于分子束外延(MBE)生长技术获得了高量子效率的InAs/GaSbT2SLs中波红外(MWIR)光电探测器结构材料,表现出了层状结构生长的光滑表面和出色的晶体结构均匀性。此超晶格中波红外探测器的50%截止波长约为5.5μm,峰值响应率为2.6 A/W,77 K下量子效率超过了80%,与碲镉汞的量子效率相当。在77 K,-50 mV偏压下的暗电流密度为1.8×10^(-6)A/cm^(2),最大电阻面积乘积(RA)(-50 mV偏压)为3.8×10^(5)Ω·cm^(2),峰值探测率达到了6.1×10^(12)cm Hz^(1/2)/W。

A very high quantum efficiency InAs/GaSb T2SL mid-wavelength infrared(MWIR)photodetector has been grown by molecular beam epitaxy(MBE).The T2SL detector structure material exhibited smooth surface with step-flow growth and excellent structural homogeneity.The 50%cut-off wavelength was about 5.5μm.The peak current responsivity was 2.6 A/W corresponding to a quantum efficiency over 80%at 77 K,which was com⁃parable to that of MCT.At 77 K,the dark current density at-50 mV bias was 1.8×10^(-6) A/cm^(2) and the resistancearea product(RA)at maximum(-50 mV bias)was 3.8×10^(5)Ω·cm^(2).The peak detectivity was calculated to be 6.1×10^(12) cm Hz^(1/2)/W.