Photoelectrical properties of Ba1-xLaxTiO3 thin-film resistor

Abstract

Thin Ba1-xLaxTiO3 film is deposited on a SiO2/Si substrate by argon ion-beam sputtering technique. The optical and photoelectrical properties of the film are studied. The optical absorption spectrum of the film is measured and the bandgap of the film is then determined. Effects of applied voltage and illumination intensity on photocurrent of thin-film resistors with different spacing lengths are investigated, and results show that devices with shorter spacing have more linear I-V characteristics. Moreover, a study of heat treatment in O2 on the dark current of the resistor is performed, revealing that a heat treatment at 400 °C for an optimal time of 10 min can greatly improve the photosensitivity of the resistor by reducing its dark current.