Effect of alloying and pressure in the structural transition of AsxP1-x system: A first principle study

Layered black arsenic-phosphorus alloy (b-AsxP1-x) is an emerging material in optoelectronics and electronics applications. In addition to its anisotropic behavior, like black phosphorus (b-P), b-AsxP1-x exhibits a narrow bandgap and improves environmental stability. Pure Phosphorus in ambient pressure prefers A17 phase where pure Arsenic prefers A7 phase. Alloying As into b-P could induce a phase transition. A previous theoretical study on AsxP1-x monolayer found the coexistence of A17 and A7 phases at x=0.07 [1]. Based on the finding, we proposed a hypothesis that there may also exist a transformation from the pure Arsenic with A7 structure to layered b-AsxP1-x with A17 structure. In this study, we concentrated on alloying as a means of structural transition and then studied the effect of pressure on this structural phase transition. To accomplish our goal, we thoroughly searched the large compositional space of AsxP1-x alloy to find the critical composition for such phase transition. Afterward, the resulting system is subjected to isotropic hydrostatic pressure to study structural and electronic changes.
[1] Nano Lett. 2015, 15, 9, 6042–6046