Wednesday, November 19, 2014
Abstract-High intrinsic mobility and ultrafast carrier dynamics in multilayer metal-dichalcogenide MoS2
Jared H. Strait, Parinita Nene, and Farhan Rana
The ultimate limitations on carrier mobilities in metal dichalcogenides, and the dynamics associated with carrier relaxation are unclear. We present measurements of the frequency-dependent conductivity of multilayer dichalcogenide MoS by optical-pump terahertz-probe spectroscopy. We find mobilities in this material approaching 4200 cmVs at low temperatures. The temperature dependence of scattering indicates that the mobility, an order of magnitude larger than previously reported for MoS, is intrinsically limited by acoustic phonon scattering at THz frequencies. Our measurements of carrier relaxation reveal picosecond cooling times followed by recombination lasting tens of nanoseconds and dominated by Auger scattering into defects. Our results provide a useful context in which to understand and evaluate the performance of MoS-based electronic and optoelectronic devices.