Optimizing 2D-metal contact in layered Tin-selenide via native oxide modulation  

作　　者：Yue Zheng Qi You Zhentian Yin Jian Tang Ke Jiang Zihao Xie Henan Li Cheng Han Yumeng Shi 

机构地区：[1]International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology of Ministry of Education,Institute of Microscale Optoelectronics,Shenzhen University,Shenzhen 518060,China [2]College of Electronics and Information Engineering,Shenzhen University,Shenzhen 518060,China

出　　处：《Nano Research》2024年第4期3014-3020,共7页纳米研究（英文版）

基　　金：support from the National Natural Science Foundation of China(Nos.62004128 and 61874074);the Fundamental Research Foundation of Shenzhen(No.JCYJ20190808152607389);the Science and Technology Project of Shenzhen(No.JCYJ20220531100815034);H.N.L.acknowledges the Guangdong Basic and Applied Basic Research Foundation(No.2022A1515012055).

摘　　要：The discovery of two-dimensional(2D)semiconductor has opened up new avenues for the development of short-channel field-effect transistors(FETs)with desired electrical performance.Among them,orthorhombic tin-selenide(SnSe)has garnered increasing attention due to its potential applications in a variety of electronic,optoelectronic,and thermoelectric devices.However,the realization of high-performance SnSe FETs with low contact resistance(Rc)remains a challenge.Herein,we systematically investigate the contact of few-layer SnSe FETs through the modulation of native oxide on SnSe by using different metals.It is found that chromium(Cr)-contacted devices possess the best FET performance,such as electron mobility up to 606 cm^(2)/(V·s)at 78 K,current on/off ratio exceeding 1010,and saturation current of~550μA/μm,where a negligible Schottky barrier(SB)of~30 meV and a low contact resistance of~425Ωμm are achieved.X-ray photoelectron spectroscopy(XPS)and cross-sectional electron dispersive X-ray spectroscopy(EDX)results further reveal that the improved contact arises from the Cr-induced reduction of native oxide(SnOx)to Sn,which thins the tunneling barrier for efficient electron injection.Our findings provide a deep insight into the 2D-metal contact of SnSe and pave the way for its applications in future nanoelectronics.

关 键 词：few-layer SnSe field-effect transistors(FETs) Cr contact native oxide contact resistance(Rc) Schottky barrier(SB) 

分 类 号：TN3[电子电信—物理电子学]