Electrical Control of Defect Assisted Trapped Excitons and trions States in Monolayer MoS₂

Unique optical properties of monolayer MoS₂ such as strong binding energy of excitons and trions at room temperature make it a suitable material to study the dynamics of these quasi particles. We report a transition between quasiparticle states using Time resolved Photoluminescence (TRPL) and Photoluminescence (PL) spectroscopy by tuning the carrier concentration of MoS₂ monolayer in FET configuration. Since the defect assisted trapping potential is electrically sensitive, we are able to control the trapping states of quasiparticle by applying gate voltage in FET. This control of defect assisted states could influence the exciton exciton annihilation mechanism which is one of the dominant nonradiative decay channel of excitons in two dimensional materials. Our study helps in understanding the exciton dynamics in 2D materials.