基于Ⅱ类超晶格的中波红外带间级联探测器(特邀)  

Mid Wavelength Interband Cascade Photodetector with TypeⅡSuperlattice Absorber(Invited)

作　　者：薛婷 黄建亮[1,2] 鄢绍龙 张艳华 马文全[1,2] XUE Ting;HUANG Jianliang;YAN Shaolong;ZHANG Yanhua;MA Wenquan(Key Laboratory of Semiconductor Materials Science,Institute of Semiconductors,Chinese Academy of Sciences,Beijing 100083,China;Center of Materials Science and Opto-electronic 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材料科学重点实验室,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：《光子学报》2023年第10期62-69,共8页Acta Photonica Sinica

基　　金：国家自然科学基金面上项目(No.61874103)。

摘　　要：为了提高红外探测器的工作温度,基于InAs/GaSb II类超晶格材料设计了一种五级带间级联结构中波红外光电探测器,并采用分子束外延技术和标准化光刻及刻蚀技术进行了器件的制备。在77 K时,该器件的50%截止波长是4.02μm,在0 V时峰值探测率为1.26×10^(12) cm·Hz^(1/2)/W;在300 K零偏压下,该器件的50%截止波长是4.88μm,峰值探测率为1.28×10^(9) cm·Hz^(1/2)/W,实现了高温探测。从180 K到300 K,器件的暗电流主要由扩散电流主导。在77 K到220 K温度范围的暗电流曲线中观察到了负微分电阻现象,并解释了峰谷电流比相对于温度变化的趋势。研究结果表明,具有带间级联结构的T2SL探测器可以进行室温工作,在中波范围内有比较明显的优势。To reduce the cryogenic cooling cost for high operating temperature applications,the dark current of infrared photodetectors need to be further reduced.Many methods have been proposed such as inserting unipolar-barrier,complementary barriers,the M-structure,and double heterostructures.The Interband Cascade Infrared Photodetectors(ICIP),originally arising from the interband cascade laser,has also been tried.The ICIP structure consists of high bandgap AlSb material,which can further reduce the dark current.Therefore,these features may make high temperature operation possible for ICIPs,especially for the mid wavelength range.This work investigates the ICIP for mid wavelength operation.The ICIP is designed as a p-i-n type.Specifically,the i region is composed of a 5-stage interband cascade structure.Each cascade stage consists of an electron-barrier(eB)layer,an absorber layer,and a hole-barrier(hB)layer,and this sequence repeats five times.The photogenerated electrons in one absorber layer should first pass through the hB layer by optical phonon assisted stepwise transport.The carriers,which arrive at the hole states of the eB layer,finally tunnel to the next absorber layer.Consequently,the energy levels of the eB and the hB layer should be equidistributed.In other words,the energy difference between adjacent levels should be comparable to the optical phonon energy,about 30 meV.The absorber layer of each period is designed as 0.5μm thick InAs(2.4 nm)/GaSb(3.6 nm)SLs,which has an expected cut-off wavelength of around 4.28μm.The hB layer is made up of 8 InAs QWs,separated by AlSb barrier layers.For the eB layer,it consists of AlSb(2.1 nm)/GaSb(5.3 nm)/AlSb(2.1 nm)/GaSb(7.5 nm)/AlSb(2.1 nm).The calculated energy separation between adjacent levels is close to the optical phonon energy.The sample is grown on an n-type GaSb(001)substrate by molecular beam epitaxy.After the growth,an array mesa was formed using standard photolithography and dry-etched.We measured the temperature-dependent dark current to reveal the dark c

关 键 词：半导体探测器 中波 分子束外延 带间级联探测器 INAS/GASB超晶格 

分 类 号：TL814[核科学技术—核技术及应用]