研究目的
To model and interpret the localized bright-exciton light emission in monolayer transition-metal dichalcogenides (TMDs), focusing on the case of WSe2 deposited on the SiO2/Si substrate and exposed to the air, by studying the impact of disorder potential originating from defects on exciton states and radiative lifetime.
研究成果
The study concludes that localized excitons in monolayer WSe2 exhibit longer radiative lifetimes compared to free excitons, with the lifetime depending on the disorder parameters and dielectric environment. The model successfully reproduces experimental observations of localized exciton spectral positions and decay times, supporting the interpretation of low-energy lines as due to localized exciton states in a disorder potential.
研究不足
The study is limited to bright exciton states and does not consider the localization of dark states or the influence of short-range/long-range electron-hole exchange. It also assumes low temperature, low-doping density, and weak excitation conditions, which may not cover all experimental scenarios.