Temperature-dependent LITT effect in c axis inclined BiCuSeO thin films.

Light-induced transverse thermoelectric (LITT) effect in c axis inclined BiCuSeO thin films was investigated in the temperature range of 80-300 K by using three different lasers with the wavelength changing from visible to mid-IR. Obvious open-circuit voltage signals were all detected when the film surface was illuminated by these lasers, and the amplitude Vp of the induced voltage signals was found to increase with the measured temperature. The improvement of Vp at a higher temperature can be explained by the enhanced anisotropy of the Seebeck coefficient as well as the reduced thermal conductivity of the film. This work demonstrates the potential application of BiCuSeO thin film as a broadband light detector working at wide temperature ranges, including a very low temperature environment.