探討多層透明導電薄膜AZO/Ag/AZO在光電元件之應用

Abstract

Transparent conducting films has high properties of transmittance and conductance in the visible range. Because of its special optical and electrical properties, it is used for many application. We report in this paper our study on Aluminum -doped ZnO (AZO) thin films and three-layered thin films, in which a Ag thin film is sandwiched in between two AZO thin films. First of all, AZO thin films were deposited on glass substrates using an RF magnetron sputter deposition method. The optical and electrical properties of AZO thin films with different deposition parameters, including sputtering power, T-S distance, working pressure and oxygen pressure, were investigated. According to the above analysis the best deposition parameters of AZO thin film can be determined. And then a three-layered thin film (AZO/Ag/AZO) was grown on the glass substrate to enhance the electrical conductivity. The Ag thin film was deposited between a fixed AZO thin film (5 ~ 15 nm) using a E-Beam deposition method. The different thickness of Ag thin film were applied. All the films obtained were characterized for the electrical and optical properties. The variation of the properties with Ag film thickness was investigated. For the physical property analysis of the AZO thin films, the microstructure and roughness of the AZO thin films which had been interlayer with different Ag thickness were measured by field emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM), respectively. For the optical property analysis of the AZO thin films, the transmittance and reflectivity of the AZO thin films which had been interlayer with different Ag thickness were measured by the ultraviolet-visible spectrophotometer (UV-VIS). For the electrical property analysis of the AZO thin films, the carrier concentration and the carrier mobility were measured by hall effect measurement system . In the experiment results,the FE-SEM and AFM analysis present the variation of the surface microstructure is as a function of Ag layer. In the transmittance part, the AZO thin films interlayer with Ag thickness of 10 nm is over 91.89 % of maximum transmittance in the visible part of the spectra (300 ~ 800 nm): the carrier concentration of 8.563 × 10-21 cm-3；mobility of 9.265 cm2/V-s；low resistivity of 3.71 × 10-4 Ω-cm. Due to the above results, the appropriate Ag layer can enhance the crystal structure, optics and electricity properties of AZO thin films. The AZO/Ag/AZO multilayer thin film is suitable as transparent conductive component for transparent electronics.