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

Area of Science:

• Condensed matter physics
• Materials science
• Thermoelectric phenomena

Background:

• The light-induced transverse thermoelectric (LITT) effect is a phenomenon where light generates a voltage perpendicular to the light propagation and applied temperature gradient.
• Bismuth copper selenide oxide (BiCuSeO) is a promising thermoelectric material with potential applications in energy harvesting and sensing.

Purpose of the Study:

• To investigate the LITT effect in c-axis inclined BiCuSeO thin films.
• To explore the temperature dependence of the LITT effect.
• To assess the potential of BiCuSeO thin films as broadband light detectors.

Main Methods:

• Thin films of BiCuSeO were prepared with c-axis inclination.
• The LITT effect was studied using three lasers with wavelengths spanning visible to mid-infrared.
• Measurements were conducted in a temperature range from 80 K to 300 K.
• Open-circuit voltage signals were measured under laser illumination.

Main Results:

• Obvious open-circuit voltage signals were detected across the entire tested wavelength range.
• The amplitude of the induced voltage (Vp) increased with increasing temperature.
• The temperature dependence of Vp was attributed to enhanced Seebeck coefficient anisotropy and reduced thermal conductivity.

Conclusions:

• BiCuSeO thin films exhibit a significant LITT effect.
• The observed temperature dependence provides insights into the underlying physical mechanisms.
• BiCuSeO thin films show promise as broadband light detectors operable at diverse temperatures, including cryogenic conditions.