Study on the dielectric properties at grain boundaries of ZnO film by electrostaticforce microscope

Purpose The purpose of this paper is to study the dielectric performance at grain boundaries of ZnO film. Design/methodology/approach ZnO thin film was prepared on glass substrate by a simple sol-gel method. The crystal structure of ZnO powders was tested by X-ray diffraction. The thickness of ZnO thin film is tested using by elliptical polarizer. The dielectric performance of ZnO thin film was investigated by electrostatic force microscope (EFM). Findings The results show that there is a significant phase angle lag and enhanced dielectric properties at the grain boundaries (GBs). The coefficient of the quadratic term “a” has an increasing function relationship with the dielectric constant of the sample. The parabolic coefficient “a” at the GBs and grain interiors is 9.02 × 10–3 and 6.25 × 10–3, respectively. Originality/value To the best of authors’ knowledge, for the first time, the dielectric performance at grain boundaries of ZnO film. ZnO thin film was investigated by EFM.