Electric-field- and strain-induced adjustability of vdW heterostructure of g-ZnO/2H-TiS2 for optoelectronic applications

Abstract

Using first-principles calculations based on density functional theory, we proposed the vdW g-ZnO/2H-TiS2 heterostructure for potential optoelectronic devices adjustable by the electric field and strain. The heterostructure showed a narrow indirect bandgap (0.34 eV) with a type-II (staggered) band alignment, a large potential drop (3.75 eV), and a large band offset, which can enhance the charge separation efficiency of its constituents, desirable for optoelectronic applications. The effects of electric field and strain on the bandgap and absorption were also studied. We showed the linearly tunable bandgap of the heterostructure by electric field and the capability of the heterostructure to preserve its semiconducting character under a wide range of strains as the main contributions of the research.