The intriguing electronic and optical properties modulation in blue phosphorene/g-III-nitrides heterostructures

In this work, the structural, electronic and optical properties of blue phosphorene (BP) and graphene-like III-nitrides, denoted as g-XN (AlN and GaN) nanocomposites are investigated by the first-principles method. Our results unveil that the hybridized BP/g-XN bilayers exhibit a decreased band gap. We also find that the optically active states of the maximum valence and minimum conduction bands are localized on opposite monolayers, leading to electrons and holes spontaneously separated, which enhances the photocatalytic efficiency. More interestingly, despite of the indirect band gap nature of the BP and g-AlN monolayers, BP/g-AlN heterostructure in most energetic preferable pattern exhibits a moderate direct band gap. The BP/g-XN heterobilayers also exhibit a significant improved visible light and UV adsorption peak, comparable or even superior to pristine BP, and the superior optical properties is robust, independent of stacking pattern. Therefore, the g-XN layers can be an excellent solution to protect the BP layer from its degradation in ambient conditions. We predict that such effective electronic band gap engineering, together with intriguing optical properties, point toward the potential of BP/g-XN heterobialyers for applications in a variety of nanodevices.