Giant Laser-induced Thermoelectric Voltage in oaxis Inclined Na_xCoO_2 Thin Films

摘要

In this paper, we have prepared oaxis inclined Na_xCoO_2 thin films on 10° and 20° tilted c-A1_2O_3 substrates and studied its light-induced thermoelectric voltage effect by using an ultraviolet pulsed laser as light source. A giant open-circuit voltage signal with the peak voltage V_p of tens of voltage was observed when the film surface was illuminated by the 308 nm pulsed radiation, and the V_p increased linearly with the inclination angle as well as the laser energy on the film. In addition, we found that Ag doping in Na_xCoO_2 films can improve the sensitivity of the thermoelectric voltage signal. The results demonstrate that c-axis inclined Na_xCoO_2 thin film has a great potential application in the detection of weak ultraviolet pulsed radiation.