Two-dimensional BX（X=P, As, Sb） Semiconductors with Mobilities Approaching Graphene
摘要：Carrier mobility plays a key role in the performance of microelectronic devices, especially the field effect transistors（FET）. To design next generation two-dimensional（2D） FET, stable channel materials with higher carrier mobility than silicon and significant band gap are highly desirable, but still not discovered. Here, we report a group of 2D materials of BX（X=P, As, and Sb）, which are semiconducting with ultrahigh carrier mobility. Using first-principles calculations, we find that all BX configurations are similar to graphene, but possess direct bandgaps of 1.36, 1.14, and 0.49 e V, respectively. Based on deformation potential theory, BX monolayers are predicted to have superior mobilities(＞10~4 cm~2V-1s-1) to phosphorene. Especially, the electron mobility of monolayer BSb is 3.2x10~5 cm~2V-1s-1, approaching the figure of merit in graphene(~3x10~5 cm~2V-1s-1). These results demonstrate that BX monolayers are of paramount significance for next-generation 2D FET manufacture.