温度诱导的SiO₂上单层和双层MoS₂光学带隙中的交叉

Temperature induced crossing in the optical bandgap of mono and bilayer MoS on SiO.

作者信息

Park Youngsin, Chan Christopher C S, Taylor Robert A, Kim Yongchul, Kim Nammee, Jo Yongcheol, Lee Seung W, Yang Woochul, Im Hyunsik, Lee Geunsik

机构信息

Department of Chemistry, School of Natural Science, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Korea.

Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, OX1 3PU, UK.

出版信息

Sci Rep. 2018 Mar 29;8(1):5380. doi: 10.1038/s41598-018-23788-3.

DOI:10.1038/s41598-018-23788-3

PMID:29599429

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC5876333/

Abstract

Photoluminescence measurements in mono- and bilayer-MoS on SiO were undertaken to determine the thermal effect of the MoS/SiO interface on the optical bandgap. The energy and intensity of the photoluminescence from monolayer MoS were lower and weaker than those from bilayer MoS at low temperatures, whilst the opposite was true at high temperatures above 200 K. Density functional theory calculations suggest that the observed optical bandgap crossover is caused by a weaker substrate coupling to the bilayer than to the monolayer.

摘要

对二氧化硅上的单层和双层二硫化钼进行了光致发光测量，以确定二硫化钼/二氧化硅界面的热效应对光学带隙的影响。在低温下，单层二硫化钼的光致发光能量和强度低于双层二硫化钼，且强度较弱，而在高于200K的高温下情况则相反。密度泛函理论计算表明，观察到的光学带隙交叉是由衬底与双层的耦合比与单层的耦合弱所致。