Two-dimensional (2D) boron phosphides (BP) represent a promising platform for integrating the complementary advantages of borophene and black phosphorus. Previous studies, however, have been largely limited to the honeycomb BP phase with a 1:1 stoichiometry, leaving unexplored the possibility of novel structures with tailored properties. Here, we performed an extensive structural exploration across 17 stoichiometric ratios of the 2D B x P 1– x system, combining structure prediction with first-principles calculations. Our results demonstrated that phosphorus-rich phases are thermodynamically favored. We identified at least five thermodynamically and dynamically stable semiconductor phases, which constitute promising candidates for experimental synthesis. The system exhibited remarkable structural diversity, encompassing puckered layers, boron-clustered sandwiches, and hexagonal bilayers, as well as a wide spectrum of electronic properties, from semiconductors with tunable bandgaps to metals exhibiting inversion-asymmetry-driven Rashba spin splitting. Notably, we predicted an intrinsic antiferromagnetic semiconducting phase in a B 6 -cage sandwich configuration stabilized by a synergistic local Stoner and Slater mechanism. Our work established a comprehensive composition–stability–configuration–property map for 2D BP. This map not only clarifies the inheritance of elemental motifs but also reveals emergent properties beyond the parent elements, substantially expanding the 2D materials family and offering a practical roadmap for experimental synthesis and functional design.
Zhao et al. (Tue,) studied this question.