Transition metal dichalcogenides are expected to be used in transparent, flexible, and highly efficient light-emitting devices. Exciton diffusion is a key factor in device applications. In this study, we measured the photoluminescence (PL) decay of excitons in a MoS2 monolayer synthesized by chemical vapor deposition on a sapphire substrate. The PL decay of A and B excitons in the femtosecond regime was observed. The PL decay curves were analyzed based on a model of exciton trapping at the deactivation center via diffusion, and the diffusion time until trapping was obtained. The diffusion coefficient and the corresponding exciton mobility were also determined. This study demonstrates the two-dimensional exciton diffusion in the femtosecond regime in the MoS2 monolayer.
Physical Review B
- Pub Date:
- May 2021
- Condensed Matter - Mesoscale and Nanoscale Physics;
- Condensed Matter - Strongly Correlated Electrons
- 9 pages 10 figures including supplemental material