Cu, Ni and Ag ions assisted preparation of nonpolar preferential oriented ZnO films with controlled morphology and optical properties

ZnO nanodevices have been widely used in practice, but one-dimensional ZnO grown in a polar preferred orientation is still partially localized. In this work, copper nitrate, nickel nitrate and silver nitrate were assisted with zinc acetate and hexamethylenetetetramine for the synthesis of ZnO films by conventional chemical bath deposition method. All samples were characterised by X-ray diffraction, field emission scanning electron microscopy, atomic force microscopy, photoluminescence, and UV-visible spectrophotometer. The results show that non-polar (110), (100) and coexisting preferred orientation ZnO films were controllably prepared by controlling the type and concentration of nitrate. On this basis, the growth process and mechanism of ZnO films with different nonpolar preferred orientations were characterized. It was also found that the ZnO films with 5 % Cu (NO3)2 & sdot;3 H2O had the minimum surface roughness. The PL spectra confirmed the type and number of defects were also related to the preferred orientations. In addition, the non-polar (110) preferred orientation ZnO films had the highest optical transmittance of 82.26 %. This work enriches the method of preparing ZnO films with various nonpolar preferred orientations and provides new ideas for the design of ZnO-based transparent nanodevices.

Automated summary

This study prepared ZnO films with various nonpolar preferred orientations using conventional chemical bath deposition method and characterized their growth process and mechanism. It was found that the type and concentration of nitrate could control the preferred orientation and surface roughness of ZnO films. Additionally, ZnO films with different preferred orientations exhibited different optical properties.