Enhanced light-induced transverse thermoelectric effect in c-axis inclined BiCuSeO thin films via Pb doping

• Published in: Optical materials express 2016-08, Vol.6 (8), p.2537-2544
• Main Authors: Wang, Lian, Yan, Guoying, Dong, Guoyi, Qiao, Shuang, Fu, Guangsheng, Wang, Shufang
• Format: Article
• Language: English
• Subjects: Doping; Electric potential; Induced voltage; Irradiation; Pulsed lasers; Thermoelectricity; Thin films; Voltage
• ISSN: 2159-3930; 2159-3930
• DOI: 10.1364/OME.6.002537

The great enhancement of light-induced transverse thermoelectric effect in c-axis inclined BiCuSeO thin films has been achieved by Pb doping. Large open-circuit thermoelectric voltage signals are all observed in the inclined Bi sub(1-x) Pb sub(x) CuSeO (x = 0, 0.04, 0.08) films when the film surface is irradiated by a 308nm pulsed laser. As the Pb doping content increases, the magnitude V sub(p) of the induced voltage signal increases greatly while the response time [tau] decrease obviously. A large figure of merit V sub(p)/[tau] of about 236.7 mV/ns is obtained in the 8% Pb-doped film sample under the 308 nm pulsed irradiation with energy density of 0.5mJ/mm super(2), which is about 25 times larger than that in the undoped film. Possible mechanism is proposed to explain the experiment results. This work might pave the way for the practical application of BiCuSeO-based thin films for high sensitive and fast response ultraviolet pulsed photodectors.