Laser-induced transverse voltage effect in c-axis inclined La _x Sr_1−x TiO₃ thin films prepared by MOCVD

Abstract

The light/thermal detector based on the laser-induced transverse voltage (LITV) effect has garnered significant interest for its rapid and broad spectral response. In this study, we prepared the La-doped STO epitaxial thin films on the 12° inclined single crystal LaAlO3(LAO) (100) substrates using our home-designed metal-organic chemical vapor deposition (MOCVD) system. Under the illumination of a 248nm laser, the LITV signals of LaxSr1-xTiO3 films were observed and showed dependence on the La doping level, which can be explained by the changes in the light absorption coefficient, thermal conductivity, and optical penetration depth. The optimized LITV signal was observed with a peak voltage of 23.25V and a decay time of 106ns under the laser power density of 1.0mJ/mm2. The high peak voltage and fast response time of LaxSr1-xTiO3 show great potential in the field of light/thermal detection.