Investigation of the electronic structure of two-dimensional GaN/Zr2CO2 hetero-junction: Type-II band alignment with tunable bandgap

By applying first-principles calculations, we construct the GaN/Zr2CO2 hetero-junction and explore its electronic structure properties. Band structure calculations indicate that GaN/Zr2CO2 junction possesses type-II band alignment. The valence band maximum (VBM) is dominated by GaN and the conduction band minimum (CBM) dominated by Zr2CO2. The large binding energy and short inter-layer spacing distance suggest that there exists chemical adsorption between the two layers beyond van der Waals (vdW) interaction. Furthermore, large conduction band offset (CBO) (2.70 eV) and powerful built-in electric field (2.34 eV) indicate that the GaN/Zr2CO2 hetero-junction may be an excellent candidate for the photo-electronic device or photocatalyst applications. We also investigated the influence of biaxial strain on the band structure of GaN/Zr2CO2. The bandgap of the GaN/Zr2CO2 hetero-junction can be tailored by biaxial strain effectively. Especially, the bandgap closes up at the compressive strain of −5%, Our calculations demonstrate that the GaN/Zr2CO2 hetero-junction is promising for tunable high-performance optoelectronic nanodevices.