Manipulation of exciton and trion quasiparticles in monolayer WS2 via charge transfer

• Published in: arXiv.org
• Main Authors: Gaur, Anand P S, Rivera, Adriana M, Dash, Saroj P, Dey, Sandwip, Katiyar, Ram S, Sahoo, Satyaprakash
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 07.06.2019
• Subjects: Charge transfer; Doping; Dynamic stability; Electrical properties; Emission spectra; Excitons; Monolayers; Optical properties; Optoelectronics; Organic chemistry; Photoluminescence; Physics - Mesoscale and Nanoscale Physics; Temperature dependence; Transition metal compounds; Trions
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1906.03126

Charge doping in transition metal dichalcogenide is currently a subject of high importance for future electronic and optoelectronic applications. Here we demonstrate chemical doping in CVD grown monolayer (1L) of WS2 by a few commonly used laboratory solvents by investigating the room temperature photoluminescence (PL). The appearance of distinct trionic emission in the PL spectra and quenched PL intensities suggest n-type doping in WS2. The temperature-dependent PL spectra of the doped 1L-WS2 reveal significant enhancement of trion emission intensity over the excitonic emission at low temperature indicating the stability of trion at low temperature. The temperature dependent exciton-trion population dynamic has been modeled using the law of mass action of trion formation. These results shed light on the solution-based chemical doping in 1L WS2 and its profound effect on the photoluminescence which is essential for the control of optical and electrical properties for optoelectronics applications.