Self-doping enhancing thermoelectric properties of GeTe thin films

Abstract

The thermoelectric film has broad application potential in the self-power supply of miniature electrical equipment. In this work, GeTe thermoelectric films were prepared using physical vapor deposition combined with annealing processes. Benefitting from the high mobility enabled by the increased crystallinity and the optimized carrier concentration via Ge self-doping, the power factor of a GeTe thin film was significantly improved to 18 μW cm−1 K−2 (300 K), and the maximum one (28 μW cm−1 K−2) was achieved at 576 K. Furthermore, thermoelectric thin film devices assembled with high-performance GeTe films exhibited superior output performance at a temperature difference of 40 K. The maximum open circuit voltage reached 12.2 mV and the power density was 2.4 mW cm−2, indicating that GeTe thin films have broad application prospects in the field of self-power supply.