Effect of Electron Beam Annealing Duration on the Properties of Zno Thin Films

Abstract

The effect of electron beam (EB) annealing duration on the properties of pure ZnO thin films was studied. Pure ZnO precursor films prepared by sol-gel spin coating method were directly annealed by EB for different duration from 20 s to 480 s. The structural, optical and electrical properties were investigated. XRD patterns show (002) preferential growth for all the ZnO films. SEM results reveal that the average grain size changes from ∼10 nm to ∼70 nm with the increase of annealing duration and AFM results show the surface RMS roughness is less than 3 nm. The optical transmittance spectra present the absorption edge of the films is at about 380 nm and the average transmittance is more than 85% in visible region. It’s exciting to find that the ZnO film annealed for only 120 s exhibits resistivity 2×10−2 Ωcm and carrier concentration as high as 5.5×1019 cm−3, which shows an advantage of EB annealing in the preparation of ZnO transparent conductive films.