A comprehensive review on the effects of doping process on the thermoelectric properties of Bi2Te3 based alloys

Bismuth Telluride (Bi2Te3) is considered as a favorable thermoelectric compound. Currently, this compound has achieved a lot of interest in sensors, chip spots, thermoelectric generators and solar cells. The doping process of some elements into Bi2Te3 based alloy is an important method for the efficiency improvement of thermoelectric devices. However, the development of high-quality devices creates a lot of challenges for researchers. Hence, this paper provides a review of different aspects of doping processes on Bi2Te3 based materials, problems and the promising ways for solving the challenges. It was concluded that doping process, annealing of specimens and creation of nanostructured compounds result in the efficiency improvement of Bi2Te3 based thermoelectric materials. Besides, it was clarified that Bi2Te2.7Se0.3 and Bi0.5Sb1.5Te3 as thin films and bulk materials are two thermoelectric compounds produced by Se and Sb doping into Bi2Te3 based materials with high figure of merit (ZT). The research indicated that thin film Bi2Te2.7Se0.3 and Bi0.5Sb1.5Te3 materials show the highest ZT values versus other materials.