Effects of Nb on the photo- and thermal sensing characteristics of Sr 0.98La 0.02TiO 3 thin-film resistor

Nb-doped Sr 0.98La 0.02TiO 3 thin-film resistor is fabricated on a SiO 2/Si substrate by argon ion-beam sputtering technique. Photo- and thermal sensing characteristics of the thin-film resistor are investigated, and the results show that besides superior sensitivity to visible light, the thin-film resistor has good thermal sensitivity with negative temperature coefficient from room temperature to 200°C, and a maximum value of -6.0%°C -1 at 30°C. With increasing Nb concentration, the photoconductive gain of the thin-film resistor increases, while the temperature coefficient firstly decreases, and then increases. It is proposed that the effects of Nb on thermal sensitivity should be closely related to the grain-boundary defects and impurities of the film, while the effects of Nb on photo-sensing should be associated with the acceptor defects in the grain boundaries. © 2004 Elsevier B.V. All rights reserved.link_to_subscribed_fulltex