Signatures of strong interlayer coupling inγ-InSe revealed by local differential conductivity  

作　　者：Xiaoshuai Fu Li Liu Li Zhang Qilong Wu Yu Xia Lijie Zhang Yuan Tian Long-Jing Yin Zhihui Qin 富晓帅;刘丽;张力;吴奇龙;夏雨;张利杰;田园;殷隆晶;秦志辉(Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education&Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices,School of Physics and Electronics,Hunan University,Changsha 410082,China)

机构地区：[1]Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education&Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices,School of Physics and Electronics,Hunan University,Changsha 410082,China

出　　处：《Chinese Physics B》2021年第8期163-168,共6页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.51772087,11804089,11574350,11904094,and 51972106);the Natural Science Foundation of Hunan Province,China(Grant Nos.2018JJ3025,2019JJ50034,and 2019JJ50073);the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB30000000);the Fundamental Research Funds for the Central Universities of China.

摘　　要：Interlayer coupling in layered semiconductors can significantly affect their optoelectronic properties.However,understanding the mechanisms behind the interlayer coupling at the atomic level is not straightforward.Here,we study modulations of the electronic structure induced by the interlayer coupling in theγ-phase of indium selenide(γ-InSe)using scanning probe techniques.We observe a strong dependence of the energy gap on the sample thickness and a small effective mass along the stacking direction,which are attributed to strong interlayer coupling.In addition,the moirépatterns observed inγ-InSe display a small band-gap variation and nearly constant local differential conductivity along the patterns.This suggests that modulation of the electronic structure induced by the moirépotential is smeared out,indicating the presence of a significant interlayer coupling.Our theoretical calculations confirm that the interlayer coupling inγ-InSe is not only of the van der Waals origin,but also exhibits some degree of hybridization between the layers.Strong interlayer coupling might play an important role in the performance ofγ-InSe-based devices.

关 键 词：indium selenide(InSe) interlayer coupling scanning tunneling microscopy/spectroscopy(STM/STS) density functional theory 

分 类 号：O471[理学—半导体物理]