Optimization of SnO2/Ag/SnO2 tri-layer films as transparent composite electrode with high figure of merit

Abstract

SnO2/Ag/SnO2 tri-layer films were prepared on quartz glass substrates by RF magnetron sputtering of SnO2 and DC magnetron sputtering of Ag. The influence of Ag layer thickness and SnO2 layer thickness on electrical and optical properties of the tri-layer films was investigated. Several analytical tools such as Hall measurements, four-point probe and ultraviolet–visible-near infrared spectrophotometer were used to explore the causes of the changes in electrical and optical properties. For the tri-layer film with top and bottom SnO2 thickness of 50nm and intermediate Ag thickness of 5nm, it exhibits the maximum figure of merit of 6.0×10−2Ω−1 with sheet resistance of 9.67Ω/sq., resistivity of 1.0×10−4Ω·cm and the average transmittance is 94.8% in the visible light region (400–800nm).