Band alignment and optoelectronic characteristics of blue phosphorene/SbN van der Waals heterostructures

Abstract

van der Waals heterostructures are promising for electronic and optoelectronic devices. Here, we theoretically construct the blue phosphorene/SbN van der Waals heterostructure to investigate the band alignment, carrier mobility and optical properties, considering the influence of interlayer distance, biaxial strain and external electric field. The results show that the structure possesses the characteristics of a staggered type-II band alignment, which promotes electron and hole distribution inside different monolayers. Especially, the band alignment can be maintained upon changes in the interlayer distance, the application of biaxial strain, and the influence of electric fields. Relative to the effects of external electric fields and biaxial strain, the interlayer distance was found to have a more substantial influence on the electronic characteristics of the heterostructure, inducing a transition from a conductor to a semiconductor. Furthermore, compared to its individual components, the heterostructure demonstrates a significant enhancement in optical absorptivity across the infrared and visible regions. Our study further confirmed that tensile strain can cause the absorption spectrum to blueshift, which enhances ultraviolet absorption and broadens the optical absorption spectrum. These findings provide significant guidance for the design and optimization of blue phosphorene-based van der Waals heterostructures for optoelectronic applications.