Dielectric function and band gap modulation in perovskite SrRuO₃ thin film

Abstract

An effective method for studying the relationship of dielectric functions and thickness in perovskite SrRuO 3 (SRO) thin film was proposed by spectroscopic ellipsometry measurement. A wedge-shaped SRO film with various thickness was prepared on SrTiO 3 substrate by pulse laser deposition, whose dielectric functions and thickness were obtained by using the Drude-Lorentz dispersive model. The acquired band gap is slightly enhanced with film thickness reducing due to the one-dimensional quantum confinement effect and the disorder effect. The proposed method is expected to be applied for dielectric modulation in perovskite photonic device.