Laser-induced voltage effects in c-axis inclined Na_xCoO_2 thin films

摘要

Laser-induced voltage effects in c-axis inclined Na_xCoO_2 thin films have been studied by using different laser sources with the wavelength ranging from ultraviolet to far infrared. Due to the transverse thermoelectric effect, a giant open-circuit voltage signal with the peak voltage V_p of about 16 V is detected when the film surface is illuminated by an ultraviolet 308 nm pulsed laser with the laser energy on the film is about 1.5 mj. Open-circuit voltage signals are also detected when the film is illuminated by the 532 nm and 10.6 μm lasers. The results demonstrate that the c-axis inclined Na_xCoO_2 thin film has a great potential application in the detection of laser radiations for wide spectral range, especially in the weak ultraviolet pulsed laser detection.