Research Highlights

Research Highlights

      Many body states like exciton, bi-exciton, trion etc. dominate the photophysical properties of the 2D materials and are instrumental for enormous optoelectronic and photovoltaic applications. Herein, our group has studied the charge carrier dynamics of exciton and trion in monolayer MoS2, followed by interfacial charge transfer dynamics in Au@MoS2.Luminescence measurements confirm the presence of both exciton and trion in MoS2, which are drastically quenched after deposition of Au NPs, indicates photo-excited electron transfer from MoS2 to Au. Ultrafast study reveals that photogenerated free carriers form excitons with a time scale of 500 fs and eventually turn into trions within 1.2 ps. Dissociation of excitons and trions has been observed in the presence of Au, with time scales of 600 fs and 3.7 ps, respectively. Understanding the formation and dissociation dynamics of the exciton and trion in monolayer MoS2 is going to help immensely to design and develop many new 2D devices. (10.1021/acs.jpclett.9b01022)