Structural, optical, and dielectric properties of sol-gel derived SrTiO3 thin films

Abstract

Transparent and crackfree SrTiO3 thin films were deposited on silicon wafers, fused silica, and stainless-steel substrates by sol-gel technique. Strontium ethyl hexanoate and titanium isopropoxide were used as starting materials. The surface topology of the films were studied by electron micrography and the structural properties by x-ray diffraction. The refractive index and band gap were measured by optical transmission and absorption spectroscopy. The films show very low leakage current and nearly temperature independent dielectric constant at high frequencies. The dielectric constant and loss factor at 1 kHz at room temperature were 131 and 0.022, respectively. The frequency dependent ac conductivity has been explained on the basis of potential barriers formed by the charge carriers trapped at intercrystalline regions.