Ultra-broadband light detection based on the light-induced transverse thermoelectric effect of epitaxial PbSe thin films with inclined structure

PbSe is a simple binary compound that has been studied extensively for use as a promising moderate-temperature thermoelectric material. In this Letter, we report the observation of the light-induced transverse thermoelectric (TTE) effect in c-axis inclined PbSe thin films that were grown epitaxially on c-axis miscut SrTiO3 single crystal substrates using the pulsed laser deposition technique. Because of the anisotropic Seebeck coefficient of these inclined PbSe thin films, high TTE voltage signals were detected when the film surfaces were irradiated using various different continuous-wave lasers with wavelengths ranging from the ultraviolet (360 nm) to the far infrared (10.6 μm). In addition, the amplitudes of the output voltage signals showed good linear dependence on both the radiation power density and the film inclination angle. The results above demonstrate the potential of PbSe for self-powered ultra-broadband light detection applications.