Wide band-response laser-induced thermoelectric voltage in tilted orientation SrTiO3 single-crystal coated by La0.7Sr0.3CoO3 layer

With different wavelengths from the infrared (IR) to ultraviolet (UV) band, laser-induced thermoelectric voltage (LITV) has been observed in the vicinal cut SrTiO3 (STO) single crystals, coated with La0.7Sr0.3CoO3 (LSCO) layer. It is demonstrated that the polarity of voltage signal in the STO substrate is reversed when the STO substrate is illuminated by UV laser rather than by IR or visible laser. The polarity of voltage signal in LSCO film is always consistent with that from the STO substrate no matter 1064 or 355 nm laser irradiate the LSCO film or the STO substrate. A possible interpretation of the phenomenon is proposed.