Enhancing the Thermoelectric Properties of N-type Bismuth-Telluride-Based Alloys Using Graphene As A Nanofiller

Abstract

Bismuth telluride chalcogenides are the ideal thermoelectric materials used for near room temperature applications. However, the usage of these materials is relegated to a few applications as a result of the extremely low heat conversion efficiencies. In this study, graphene is used as a nanofiller to prepare n-type bismuth telluride nanocomposite of a composition Bi2Te2.7Se0.3. The samples were prepared via a ball milling technique with different graphene concentrations and processing times. The results revealed that graphene addition during the last phase of milling improved the thermoelectric properties. However, these enhancements were limited to the lower graphene concentration of 0.05 wt.% only. Moreover, the figure-of-merit values of the optimum sample showed noticeable enhancements of 19%, reaching 0.5 at room temperature and 23 % at 160 ?C, reaching a maximum figure-of-merit value of 0.81. Hence, proving the ability of graphene to enhance the thermoelectric properties of the sample under study.