Strain-enhanced power conversion efficiency of a BP/SnSe van der Waals heterostructure

Abstract

A promising BP/SnSe van der Waals (vdW) photovoltaic heterostructure was designed and investigated by first-principles calculations. The BP/SnSe vdW heterostructure showed inhibition of photogenerated carrier recombination 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 exhibited anisotropic characteristics reaching approximately 10³ cm² V⁻¹ s⁻¹, with an intrinsic power conversion efficiency (PCE) of 11.96%. Our results show that the PCE can be increased 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 great potential for use in photovoltaic devices.