Preparation and investigation of nano-thick FTO/Ag/FTO multilayer transparent electrodes with high figure of merit

摘要

In order to improve the conductivity of the single–layered nano-thick F doped SnO2 (FTO) thin films, an Ag mid–layer is embedded between the FTO layers. In our work, the effects of mid–layer Ag and top FTO layer on the structural, electrical and optical properties of FTO/Ag/FTO multilayered composite structures deposited on quartz glass substrates by magnetron sputtering at 100 °C have been investigated. As the thickness of Ag mid–layer increases, the resistivity decreases. As the top FTO layer thickness increases, the resistivity increases. The highest value of figure of merit φTC is 7.8 × 10⁻²Ω⁻¹ for the FTO (20 nm)/Ag (7 nm)/FTO (30 nm) multilayers, while the average optical transmittance is 95.5% in the visible range of wavelengths and the resistivity is 8.8 × 10⁻⁵Ω·cm. In addition, we also describe the influence of Ag and top FTO layer thickness on structural, electrical and optical properties of the nano-thick FTO (20 nm)/Ag/FTO multilayers and the mechanism of the changes of electrical and optical properties at different Ag and top FTO layer thicknesses.