  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.
