One key challenge in developing postsilicon electronic technology is to find ultrathin channel materials with high charge mobilities and sizable energy band gaps. Graphene can offer extremely high charge mobilities; however, the lack of a band gap presents a significant barrier. Transition metal dichalcogenides possess sizable and thickness-tunable band gaps; however, their charge mobilities are relatively low. Here we show that black phosphorus has room-temperature charge mobilities on the order of 10(4) cm(2) V(-1) s(-1), which are about 1 order of magnitude larger than silicon. We also demonstrate strong anisotropic transport in black phosphorus, where the mobilities along the armchair direction are about 1 order of magnitude larger than in the zigzag direction. A photocarrier lifetime as long as 100 ps is also determined. These results illustrate that black phosphorus is a promising candidate for future electronic and optoelectronic applications.
Keywords: black phosphorus; carrier lifetime; charge transport; transient absorption.