Carrier Dynamics in High-density Photo-doped MoS₂: Monolayer vs Multilayer

Monolayer and multilayer MoS₂ are extremely fascinating materials for the use in lasers, compact optical parametric amplifiers, and high-power detectors which demands high excitation light-matter interaction. Consequently, it is essential to understand the carrier dynamics in both the cases at such high excitation densities. In this work, we investigate the carrier dynamics of monolayer and multilayer MoS₂ at photo-doping densities around Mott Density. It is observed that, despite the similarity in band structure near K-point and formation of A-exciton, a substantial difference in the carrier dynamics is observed reflecting the influence of the entire band structure. The exciton dissociation, bandgap renormalization, and intervalley relaxation play a consequential role in dictating the ultrafast transient properties of these samples. The study in this paper provide a substantial understanding of fundamental optoelectronic properties of the two-dimensional MoS₂, paving a way for its potential applications in various photonic and optoelectronic domain.