通过光谱椭偏仪评估的MoS和WS异质结构光学性质的温度依赖性。

Temperature Dependence of Optical Properties of MoS and WS Heterostructures Assessed by Spectroscopic Ellipsometry.

作者信息

Nguyen Hoang Tung, Le Van Long, Nguyen Thi Mai, Bui Xuan Khuyen, Nguyen Thi Giang, Nguyen Nhat Linh, Nguyen Xuan Au, Kim Tae Jung

机构信息

Institute of Materials Science, Vietnam Academy of Science and Technology, Hanoi 100000, Vietnam.

Department of Physics, Kyung Hee University, Seoul 02447, Republic of Korea.

出版信息

Nanomaterials (Basel). 2025 Jan 6;15(1):76. doi: 10.3390/nano15010076.

DOI:10.3390/nano15010076

PMID:39791834

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC11723339/

Abstract

We report the complex dielectric function = + of MoS/WS and WS/MoS heterostructures and their constituent monolayers MoS and WS for an energy range from 1.5 to 6.0 eV and temperatures from 39 to 300 K. Comparisons between the optical properties of the heterostructures and their monolayers were conducted. Critical-point (CP) energies of the heterostructures were traced back to their origins in the monolayers. Low-temperature measurements confirmed the existence of only three excitonic CPs from 1.5 to 2.5 eV due to the overlap of trion of the MoS monolayer and exciton of the WS monolayer. Due to the dielectric screening effect, most CPs exhibit red shifts in the heterostructures compared to their monolayer counterparts.

摘要

我们报告了MoS₂/WS₂和WS₂/MoS₂异质结构及其组成单层MoS₂和WS₂在1.5至6.0 eV能量范围以及39至300 K温度下的复介电函数ε = ε₁ + iε₂。对异质结构及其单层的光学性质进行了比较。异质结构的临界点（CP）能量可追溯到其在单层中的起源。低温测量证实，由于MoS₂单层的三重激子（trion）与WS₂单层的激子重叠，在1.5至2.5 eV范围内仅存在三个激子CP。由于介电屏蔽效应，与单层对应物相比，大多数CP在异质结构中表现出红移。