Interface State Luminescence and Sub‐Bandgap Absorption Based on CuGaO2 Nanoplates/ZnO Nanowires Heterostructure Arrays

Abstract

In this paper, the vertical arrays of ZnO nanowires (NWs) are uniformly grown on the surface of hexagonal CuGaO2 (CGO) nanoplates (NPs) through the hydrothermal method, forming the high‐density p–n heterojunction. The photoluminescence (PL) properties of these hetero‐assembled structures are characterized, and an obvious ultraviolet (UV) emission centered at 392.32 nm has been observed. Compared with the PL spectra of pure ZnO NWs, the UV peak red‐shift occurred and the spectrum broadened almost 2.5 times. A new emission located at 398 nm is attributed to the interface recombination which has been found through the Gaussian fitting. Furthermore, a red‐shift also appears in the absorption spectra of CGO NPs/ZnO NWs heterostructure, and the variation of light absorption properties results from the sub‐bandgap absorption effect in the p–n junction region. The light emission and absorption mechanisms occurring at the heterojunction have been investigated in terms of energy band theory. This work offers a new insight to realize micro/nano optoelectronic devices based on p‐CGO NPs/n‐ZnO NWs hetero‐assembled structures.