Back to Search Start Over

Evolution of the Electronic Band Structure and Efficient Photo-Detection in Atomic Layers of InSe

Authors :
Lei, Sidong
Ge, Liehui
Najmaei, Sina
George, Antony
Kappera, Rajesh
Lou, Jun
Chhowalla, Manish
Yamaguchi, Hisato
Gupta, Gautam
Vajtai, Robert
Mohite, Aditya D.
Ajayan, Pulickel M.
Source :
ACS Nano; February 2014, Vol. 8 Issue: 2 p1263-1272, 10p
Publication Year :
2014

Abstract

Atomic layers of two-dimensional (2D) materials have recently been the focus of extensive research. This follows from the footsteps of graphene, which has shown great potential for ultrathin optoelectronic devices. In this paper, we present a comprehensive study on the synthesis, characterization, and thin film photodetector application of atomic layers of InSe. Correlation between resonance Raman spectroscopy and photoconductivity measurements allows us to systematically track the evolution of the electronic band structure of 2D InSe as its thickness approaches few atomic layers. Analysis of photoconductivity spectra suggests that few-layered InSe has an indirect band gap of 1.4 eV, which is 200 meV higher than bulk InSe due to the suppressed interlayer electron orbital coupling. Temperature-dependent photocurrent measurements reveal that the suppressed interlayer interaction also results in more localized pz-like orbitals, and these orbitals couple strongly with the in-plane E′ and E″ phonons. Finally, we measured a strong photoresponse of 34.7 mA/W and fast response time of 488 μs for a few layered InSe, suggesting that it is a good material for thin film optoelectronic applications.

Details

Language :
English
ISSN :
19360851 and 1936086X
Volume :
8
Issue :
2
Database :
Supplemental Index
Journal :
ACS Nano
Publication Type :
Periodical
Accession number :
ejs31866822
Full Text :
https://doi.org/10.1021/nn405036u