Tunable Band Alignment in the Arsenene/WS₂ Heterostructure by Applying Electric Field and Strain

Arsenene has received considerable attention because of its unique optoelectronic and nanoelectronic properties. Nevertheless, the research on van der Waals (vdW) heterojunctions based on arsenene has just begun, which hinders the application of arsenene in the optoelectronic and nanoelectronic fields. Here, we systemically predict the stability and electronic structures of the arsenene/WS₂ vdW heterojunction based on first-principles calculations, considering the stacking pattern, electric field, and strain effects. We found that the arsenene/WS₂ heterostructure possesses a type-II band alignment. Moreover, the electric field can effectively tune both the band gap and the band alignment type. Additionally, the band gap could be tuned effectively by strain, while the band alignment type is robust under strain. Our study opens up a new avenue for the application of ultrathin arsenene-based vdW heterostructures in future nano- and optoelectronics applications. Our study demonstrates that the arsenene/WS₂ heterostructure offers a candidate material for optoelectronic and nanoelectronic devices.