The optical and tunable electronic properties of WTe2/ZnI2 heterostructures under the influence of strain and electric field

The structural arrangement, as well as the electrical characteristics and optical attributes, of the ZnI2/WTe2 heterojunction are determined using Density Functional Theory (DFT) first principles. Final results demonstrate the ZnI2/WTe2 heterojunction as a type II van der Waals heterojunction featuring a band gap of 0.54eV, enabling the effective division of electron-hole pairs generated by light absorption. Applying electric field and strain to the heterojunction allows for the adjustment of the band gap to zero, facilitating the successful transition from a semiconductor to metal. This change is accompanied by the conversion of the indirect band gap to a direct band gap. Interestingly, the ZnI2/WTe2 heterojunction exhibits a greater light absorption capacity compared to the two monolayers. The properties suggest that the ZnI2/WTe2 heterojunction holds significant promise in the field of photoelectronic devices, including photodetectors.