Regulating the conductance of tungsten diselenide by oxygen plasma and improving its electrical stability by encapsulation  

作　　者：Zhaofang Cheng Shaodan He Shimin Zhang Shijun Duan Min Wang Ziyu Liu Rong Zhang Wenya Qiang Xudong Zhang Minggang Xia 

机构地区：[1]MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter,School of Physics,Xi’an Jiaotong University,Xi’an 710049,China [2]Department of Applied Physics,School of Physics,Xi’an Jiaotong University,Xi’an 710049,China [3]Shaanxi Province Key Laboratory of Quantum Information and Optoelectronic Quantum Devices,School of Physics,Xi’an Jiaotong University,Xi’an 710049,China

出　　处：《Nano Research》2024年第4期3253-3260,共8页纳米研究（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.11774278);the Fundamental Research Funds for Central Universities(No.2012jdgz04).

摘　　要：Two-dimensional(2D)tungsten selenide(WSe_(2))is promising candidate material for future electronic applications,owing to its potential for ultimate device scaling.For improving the electronic performance of WSe_(2)-based field-effect transistors(FETs),the modification of surface properties is essential.In this study,the seamless structural phase transition in WSe_(2) lattice is achieved by soft oxygen plasma,regulating the electrical conductance of WSe_(2)-based FETs.We found that during the soft oxygen plasma treatment with optimal processing time,the generated oxygen ions can substitute some selenium atoms and thus locally modify the bond length,inducing 2H→1T phase transition in WSe_(2) with seamless interfaces.The mosaic structures have been proven to tailor the electronic structure and increase the hole carrier concentration inside WSe_(2),significantly increasing the channel conductance of WSe_(2) FETs.With the further increase of the oxygen plasma treatment time,the creation of more selenium vacancy defects leads to the electronic doping,resulting in the reduction of conductance.Benefiting from the hexagonal boron nitride(h-BN)encapsulation to interrupt the partial structural relaxation from 1T to 2H phase,our WSe_(2) FET exhibits high electronic stability with conductance of 6.8×10^(-4) S,which is about four orders of magnitude higher than 2H WSe_(2)(5.8×10^(-8) S).This study could further broaden the WSe_(2) FETs in applications for functionalization and integration in electronics.

关 键 词：tungsten selenide(WSe2) structural phase transition oxygen plasma CONDUCTANCE hexagonal boron nitride(h-BN)encapsulation 

分 类 号：O53[理学—等离子体物理]