Affiliation:
1. Department of Materials Science and Engineering National Yang Ming Chiao Tung University Hsinchu 30010 Taiwan
2. Department of Materials Science and Engineering National Tsing Hua University Hsinchu 30013 Taiwan
3. Department of Materials and Optoelectronic Science National Sun Yat‐sen University Kaohsiung City 80424 Taiwan
Abstract
AbstractIncorporating dilute doping and controlled synthesis provides a means to modulate the microstructure, defect density, and transport properties. Transmission electron microscopy (TEM) and geometric phase analysis (GPA) have revealed that hot‐pressing can increase defect density, which redistributes strain and helps prevent unwanted Ge precipitates formation. An alloy of GeTe with a minute amount of indium added has shown remarkable TE properties compared to its undoped counterpart. Specifically, it achieves a maximum figure‐of‐merit zT of 1.3 at 683 K and an exceptional TE conversion efficiency of 2.83% at a hot‐side temperature of 723 K. Significant zT and conversion efficiency improvements are mainly due to domain density engineering facilitated by an effective hot‐pressing technique applied to lightly doped GeTe. The In–GeTe alloy exhibits superior TE properties and demonstrates notable stability under significant thermal gradients, highlighting its promise for use in mid‐temperature TE energy generation systems.
Funder
Ministry of Education
National Science and Technology Council