Discovering and Understanding 2D Semiconductors with High Intrinsic Carrier Mobility at Room Temperature

Abstract: Two-dimensional (2D) semiconductors have demonstrated great potential for next-generation electronics and optoelectronics. However, the current 2D semiconductors suffer from intrinsically low carrier mobility at room temperature, which significantly limits its applications. Here we discover a variety of new 2D semiconductors with mobility one order of magnitude higher than the current ones. The discovery is made by developing effective descriptors for high-throughput computationally screening of the 2D materials database, followed by using state-of-the-art first principles method to accurately calculate the mobility. Further analyses attribute their exceptional mobilities to small effective mass, high sound velocity, high optical phonon frequency, small ratio of Born charge vs. polarizability, and/or weak electron-phonon coupling. Our work opens up new materials to realize high device performance and/or exotic physics that are difficult to achieve previously, and improves the understanding of the carrier transport mechanism.