Investigation on p-type doping of PBn unipolar barrier InAsSb photodetectors  

PBn单极势垒型InAsSb光电探测器p型掺杂研究

作　　者：ZHANG Jian CHANG Chao LI Hong-Fu SHI Yu-Na YIN Han-Xiang LI Yan-Hui YUE Biao WANG Hai-Peng YAN Chang-Shan DAI Xin-Ran DENG Gong-Rong KONG Jin-Cheng ZHAO Peng ZHAO Jun 张健;常超;李红福;石玉娜;殷瀚翔;李艳辉;岳彪;王海澎;闫常善;戴欣冉;邓功荣;孔金丞;赵鹏;赵俊(昆明物理研究所,云南昆明650223;北京理工大学光学与光子学院北京市混合现实与先进显示工程技术研究中心,北京100081)

机构地区：[1]Kunming Institute of Physics,Kunming 650223,China [2]Beijing Engineering Research Center of Mixed Reality and Advanced Display,School of Optics and Photonics,Beijing Institute of Technology,Beijing 100081,China

出　　处：《红外与毫米波学报》2024年第4期472-478,共7页Journal of Infrared and Millimeter Waves

基　　金：Supported by the Candidate Talents Training Fund of Yunnan Province(202205AC160054);the National Natural Science Foundation of China(62174156)。

摘　　要：The lattice-matched XBn structures of InAsSb,grown on GaSb substrates,exhibit high crystal quali⁃ty,and can achieve extremely low dark currents at high operating temperatures(HOT).Its superior performance is attributed to the unipolar barrier,which blocks the majority carriers while allowing unhindered hole transport.To further explore the energy band and carrier transport mechanisms of the XBn unipolar barrier structure,this pa⁃per systematically investigates the influence of doping on the dark current,photocurrent,and tunneling character⁃istics of InAsSb photodetectors in the PBn structure.Three high-quality InAsSb samples with unintentionally doped absorption layers(AL)were prepared,with varying p-type doping concentrations in the GaSb contact layer(CL)and the AlAsSb barrier layer(BL).As the p-type doping concentration in the CL increased,the device’s turn-on bias voltage also increased,and p-type doping in the BL led to tunneling occurring at lower bias voltages.For the sample with UID BL,which exhibited an extremely low dark current of 5×10^(-6) A/cm^(2).The photocurrent characteristics were well-fitted using the back-to-back diode model,revealing the presence of two opposing space charge regions on either side of the BL.在GaSb衬底上外延生长晶格匹配的XBn结构InAsSb具有高晶体质量,在高工作温度(HOT)下能够实现极低的暗电流。该结构具有优越的性能,在阻挡多数载流子的同时,不影响空穴传输。为了进一步探索XBn单极势垒结构的能带和载流子输运机理,系统地研究了掺杂对PBn结构InAsSb光电探测器的暗电流、光电流和隧穿特性的影响。制备了三个高质量InAsSb样品,吸收层(AL)均为非故意掺杂(UID),对接触层(CL)和势垒层(BL)进行不同浓度的p型掺杂。随着CL中p型掺杂浓度的增加,器件的开启偏压变大,而BL中的p型掺杂会导致隧穿效应发生在更低的偏置电压下。对于BL非故意掺杂的样品,表现出极低的暗电流,仅为5×10^(-6)A/cm^(2)。该样品的器件光电流特性可以通过背靠背二极管模型拟合,揭示了BL两侧存在两个反向的空间电荷区。

关 键 词：INASSB PBN p-type doping dark current 

分 类 号：O475[理学—半导体物理]