Optical properties of Cu and Ru doped BST thin films with additive glycerol and MESA surfactant

Abstract

In this paper, barium strontium titanate (BST) thin films were deposited by chemical solution deposition (CSD) with addition glycerol and methyl ester sulfonic acid (MESA) surfactant as additive materials. The effect of variation spinning speed (5500 and 8000 rpm), different dopant (Cu and Ru dopants), and also additive materials on optical properties were studied by Spectrophotometer Vis-NIR. As a result, BST thin films with additive MESA have higher absorbance and similar spectrum pattern than additive glycerol. Generally, BST thin films with MESA surfactant had band gap smaller than glycerol of BST thin films. Absorption and extinction coefficient of BST with glycerol were observed and we reported Ru doped BST at spinning speed 5500 rpm had higher value than other films. On other hand, Cu doped BST at 8000 rpm had absorption and extinction coefficient higher than other films.