We report a transient absorption microscopy study of charge carrier dynamics in bulk MoS2 crystals at room temperature. Charge carriers are injected by interband absorption of a 555-nm pulse, and probed by measuring differential reflection of a time-delayed and spatially scanned 660-nm pulse. We find an intervalley transfer time of about 0.35 ps, an energy relaxation time of hot carriers on the order of 50 ps, and a carrier lifetime of 180 ps. By monitoring the spatiotemporal dynamics of carriers, we obtained a diffusion coefficient of thermalized electrons of 4.2 cm2/s, corresponding to a mobility of 170 cm2/Vs. We also observed a time-varying diffusion coefficient of hot carriers.
@article{arxiv.1303.0749,
title = {Charge carrier dynamics in bulk MoS2 crystal studied by transient absorption microscopy},
author = {Nardeep Kumar and Jiaqi He and Dawei He and Yongsheng Wang and Hui Zhao},
journal= {arXiv preprint arXiv:1303.0749},
year = {2015}
}