  Atomically-thin molybdenum disulfide is emerging as a new nanomaterial with
potential applications in the fields of electronic and photonics. Charge
carrier dynamics plays an essential role in determining its electronic and
optical properties. We report spatially and temporally resolved pump-probe
studies of charge carriers in atomically-thin molybdenum disulfide samples
fabricated by mechanical exfoliation. Carriers are injected by interband
absorption of a 390-nm pump pulse and detected by measuring differential
reflection of a time-delayed and spatially-scanned probe pulse that is tuned to
an exciton transition. Several parameters on charge carrier dynamics are
deduced, including carrier lifetime, diffusion coefficient, diffusion length,
and mobility.
