Large Electrical Conductivity and Thermoelectric Power Factor of Pulsed Laser-Deposited Zn1-x Ga x O Thin Films

Developing highly efficient transparent thermoelectric oxide thin films is the key for futuristic devices, including ecofriendly portable and sustainable electronic devices. In this paper, we report a large thermoelectric power factor of pulsed laser-deposited ZnO and Ga-doped ZnO thin films. Nearly a 40-fold enhancement in electrical conductivity from 118 S cm(-1) (ZnO) to 5050 S cm(-1) (Zn0.98Ga0.02O) is realized with Ga doping. We show that a thermoelectric power factor as high as similar to 2.8 and 2.1 mW m(-1) K-2 can be achieved for ZnO and Zn0.97Ga0.03O thin films, respectively, at temperatures >= 640 K. Our findings suggest that the observed large thermoelectric power factor is a result of enhanced electrical conductivity due to the presence of substantial native oxygen vacancy defects (V-O) in the Zn1-xGaxO thin films. Our results may facilitate the realization of high-performance transparent solid-state thin film thermoelectric devices.