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

Overview

Journal Nanomaterials (Basel)

Date 2025 Jan 10

PMID 39791834

Authors

Hoang Tung Nguyen

Van Long Le

Thi Mai Nguyen

Xuan Khuyen Bui

Thi Giang Nguyen

Nhat Linh Nguyen

Xuan Au Nguyen

Tae Jung Kim

Affiliations

Soon will be listed here.

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.

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