Effects of annealing conditions on photoelectrical properties of Ba1-xSrxNbyTi1-yO3 thin-film resistor

The optical characteristics of barium-strontium titanate-niobate (Ba 1-xSrxNbyTi1-yO3) thin-film resistor are investigated and the effects of annealing gas and annealing temperature on photoelectrical properties are studied. Experimental results show that Ba1-xSrxNbyTi 1-yO3 thin films are highly sensitive not only to visible light, but also to ultraviolet light. As compared to N2-annealed devices, O2-annealed devices have higher photosensitivity and lower dark current. Moreover, the photosensitivity of the O2-annealed devices is reduced for higher annealing temperature. Based on scanning electron microscope (SEM) study and grain-boundary theory, it can be concluded that 400 °C in O2 is the optimal annealing condition, which can give a photosensitivity as high as 8400% to visible light and 5500% to ultraviolet light. © 2006 IOP Publishing Ltd.link_to_subscribed_fulltex