Light-induced transverse thermoelectric effect in miscut GaAs single crystals by far-infrared laser illumination

Abstract

Light-induced transverse voltage (LITV) effect was investigated in miscut GaAs (0 0 1) single crystals by a 10.6 µm continuous wave CO2 laser with low power density. Open-circuit voltage signals were observed when the sample surface was illuminated by the 10.6 µm radiation and the magnitude of the voltage increased linearly with the miscut angle as well as the laser power on the samples. The voltage sensitivity can be improved after coating a layer of graphite light absorber on the surface of the sample. Moreover, open-circuit voltage signals were also detected when the surface of the samples was heated by a thermal heater. The results suggest that the LITV in miscut GaAs single crystals mainly originates from the transverse thermoelectric effect. This work demonstrates that the miscut GaAs single crystals have potential applications for detecting optical and thermal radiations.