Effects of annealing conditions on photoelectrical properties of Ba_1−xSr_xNb_yTi_1−yO₃thin-film resistor

Abstract

The optical characteristics of barium-strontium titanate-niobate (Ba 1−x Sr x Nb y Ti 1−y O 3 ) thin-film resistor are investigated and the effects of annealing gas and annealing temperature on photoelectrical properties are studied. Experimental results show that Ba 1−x Sr x Nb y Ti 1−y O 3 thin films are highly sensitive not only to visible light, but also to ultraviolet light. As compared to N 2 -annealed devices, O 2 -annealed devices have higher photosensitivity and lower dark current. Moreover, the photosensitivity of the O 2 -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 O 2 is the optimal annealing condition, which can give a photosensitivity as high as 8400% to visible light and 5500% to ultraviolet light.