Electronic Structure and Carrier Mobility of Two-Dimensional α Arsenic Phosphide

Using first-principles calculations, we investigate electronic structures of alpha arsenic phosphide under strain. It is a two-dimensional monolayer composed of an equimolar mixture of phosphorus and arsenic, whose multilayer correspondents were synthesized very recently. According to structure optimizations and phonon calculations, the alpha phase branches into three distinct allotropes. Monolayers of the alpha(1) and alpha(3) phases are direct-gap semiconductors with band gaps that are similar to that of the alpha phosphorene. They exhibit anisotrpic carrier mobility. Specifically, the alpha(3) phase exhibits the electron mobility of similar to 10 000 cm(2)V(-1) s(-1), which is 1 order of magnitude larger than that for the alpha phosphorene. Likewise, their electronic structures display highly anisotropic behavior under strain different from that of the a phosphorene. The complex response under strain can be mostly understood in terms of the relative alignment of bonding and antibonding As-P states under a specific strain.