Band alignment of heterojunctions formed by PtSe₂ with doped GaN

In order to investigate the effect of different doping types on the band alignment of heterojunctions, we prepared PtSe₂/n-GaN, PtSe₂/p-GaN, and PtSe₂/u-GaN heterojunctions by wet transfer technique. The valence band offsets (VBO) of the three heterojunctions were measured by x-ray photoelectron spectroscopy (XPS), while the PtSe₂/n-GaN is 3.70±0.15 eV, PtSe₂/p-GaN is 0.264±0.15 eV, and PtSe₂/u-GaN is 3.02±0.15 eV. The conduction band offset (CBO) of the three heterojunctions was calculated from the material bandgap and VBO, while the PtSe₂/n-GaN is 0.61±0.15 eV, PtSe₂/p-GaN is 2.83±0.15 eV, and PtSe₂/u-GaN is 0.07±0.15 eV. This signifies that both PtSe₂/u-GaN and PtSe₂/p-GaN exhibit type-I band alignment, but the PtSe₂/n-GaN heterojunction has type-III band alignment. This signifies that the band engineering of PtSe₂/GaN heterojunction can be achieved by manipulating the concentration and type of doping, which is significantly relevant for the advancement of related devices through the realization of band alignment and the modulation of the material properties of the PtSe₂/GaN heterojunction.