Abstract
Two-dimensional(2D)materials have gained considerable attention in chemical sensing owing to their naturally high surface-to-volume ratio.However,the poor response time and incomplete recovery re-strict their application in practical,high performance gas sensors.In this work,we fabricated air-stable ReS2/GaSe heterostructure-based NO2 gas sensors with excellent gas sensing response,recovery,selectiv-ity and a low limit of detection(LOD)toward nitrogen dioxide(NO2).The ReS2/GaSe heterostructure was prepared via mechanical exfoliation and an all-dry transfer method.Before the sensing measurements,temperature-dependant transport measurements were carried out.The Schottky Barrier Height(SBH)of the ReS2/GaSe heterostructure was calculated and the corresponding transport mechanisms were dis-cussed.The fabricated gas sensors showed a significant response enhancement with full reversibility to-ward ppm-level NO2(response of～17％at 3 ppm,a LOD of～556 ppb)at an operating temperature of(33 ℃).In particular,the total response and recovery time of the ReS2/GaSe was revealed to be less than 4 min(～38 s and～174 s,respectively)for the 250 ppm concentration,which is one of the best response and recovery time toward ppm-level NO2.The excellent sensing performances and recovery characteris-tics of the ReS2/GaSe structure are attributed to its efficient charge separation,unique interlayer coupling and desirable band alignments.This atomically thin,ultrasensitive gas sensor that operates at room tem-perature is a strong technological contender to conventional metal oxide gas sensors,which often require elevated temperatures.
基金项目
Basic Science Research Program through the National Research Foundation of Korea(NRF)(2018R1A6A1A03025708)
Nano-Material Technology Development Program through the National Research Foundation of Korea(NRF)()
Ministry of Science,ICT and Future Planning(2009-0082580)
NETL
NSTL
万方数据