Band engineering, carrier density control, and enhanced thermoelectric performance in multi-doped SnTe

Abstract

Thermoelectric energy conversion is one of the most important applications of functional materials for energy. To realize practical applications, high conversion efficiency is required over a wide range of temperatures. Furthermore, abundance as well as environmental load of the elements constituting thermoelectric materials are important aspects to be considered. We report high thermoelectric performance over a wide range of temperatures in doped SnTe with multiple elements by exploiting synergistic effects of band convergence, resonance level formation, and carrier density optimization. An averaged ZT value between near room temperature and around 800 K is found to exceed 0.80 for Sn0.92Mn0.10In0.01Bi0.01Cu0.01Te, which shows that the SnTe-based thermoelectrics possess high potential for practical applications.