-SiS/black phosphorus van der Waals heterostructure: A promising anode material for sodium-ion batteries

Black phosphorene (BlackP), like alpha-SiS, is a two-dimensional semiconducting material for advanced microelectronics, with a moderate band gap. Even yet, the epitaxial growth of alpha-SiS on a fertile substrate has proven to be a formidable obstacle, delaying its widespread production for technological applications. Here based on first-principles approaches we identify that alpha-SiS (which is not a layered material in bulk form) monolayer could be stabilized either in freestanding form or supported on few layers of a BlackP substrate owing to its isovalency nature and the inherent structural resemblance between the two. Our calculation results demonstrate that alpha-SiS monolayer is stable on BlackP. Furthermore, the synergistic interfacial effect makes BlackP-like alpha-SiS and BlackP (alpha-SiS/BlackP) van der Waals (vdW) heterostructure a viable contender for power-driving sodium-ion batteries owing to relatively high binding strength, ultrafast diffusivity (0.08 eV in region-III), transition from semiconducting to upon sodiation, and substantially high theoretical capacity (329 mAhg(-1)). Moreover, the alpha-SiS/BlackP vdW heterostructure possesses high optical absorption strength similar to 10(5) cm(-1), and can effectively harvest visible solar radiation. The alpha-SiS growth on such semiconducting substrates could become a novel platform for next-generation nano-energy technology.