An infrared sensor, based on the principle of electron emission from a thin Pb(ZrTi,)O-3 (PZT) plate, is proposed in this study. The electron emission current from a thin, single crystalline SrTiO3 plate caused by infrared light irradiation was observed at an electriefield of 1.6 MV/cm. To compare the electron emission characteristics, a sintered PZT and a single crystalline SrTiO3 emitter were measured under the same infrared light irradiation conditions. The peak emission current from the SrTiO3 plate was 1.6 times higher than that of the PZT emitter, and the response speed was faster. However, the emission current did not respond continuously to a pulsed infrared irradiation. (C) 2004 American Vacuum Society.