Strain Enhanced Power Conversion Efficiency of BP/SnSe Van der Waals Heterostructure
A promising BP/SnSe van der Waals (vdW) photovoltaic heterostructure is designed and investigated by first-principles calculations. The BP/SnSe vdW heterostructure shows inhibiting recombination of photogenerated carriers as well as broad and high optical absorption intensity spanning the visible to deep ultraviolet regions reaching the order of 105 cm-1. The carrier mobility of the BP/SnSe vdW heterostructure exhibits anisotropic characteristics reaching ~103 cm2·V-1·s-1 and the intrinsic power conversion efficiency (PCE) is 11.96%. Our results show that the PCE can be improved to 17.24% when the conduction band offset between BP and SnSe is reduced by strain engineering. The distinctive and favorable properties suggest that the BP/SnSe vdW heterostructure has large potential in photovoltaic devices.