Charge transfer engineering to achieve extraordinary power generation in GeTe-based thermoelectric materials

Chengyan Liu; Zhongwei Zhang; Ying Peng; Fucong Li; Lei Miao; Eiji Nishibori; Raju Chetty; Xiaobo Bai; Ruifan Si; Jie Gao; Xiaoyang Wang; Yanqiu Zhu; Nannan Wang; Haiqiao Wei; Takao Mori

doi:10.1126/sciadv.adh0713

Charge transfer engineering to achieve extraordinary power generation in GeTe-based thermoelectric materials

Sci Adv. 2023 Apr 28;9(17):eadh0713. doi: 10.1126/sciadv.adh0713. Epub 2023 Apr 26.

Authors

Chengyan Liu¹, Zhongwei Zhang², Ying Peng^{3

4}, Fucong Li¹, Lei Miao¹, Eiji Nishibori⁵, Raju Chetty³, Xiaobo Bai¹, Ruifan Si¹, Jie Gao¹, Xiaoyang Wang¹, Yanqiu Zhu², Nannan Wang², Haiqiao Wei⁶, Takao Mori^{3

7}

Affiliations

¹ Guangxi Key Laboratory of Information Materials, Engineering Research Center of Electronic Information Materials and Devices, Ministry of Education, School of Materials Science and Engineering, Guilin University of Electronic Technology, Guilin 541004, China.
² School of Chemistry and Chemical Engineering and School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China.
³ International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba 305-0044, Japan.
⁴ Guangxi Key Laboratory of Precision Navigation Technology and Application, School of Information and Communication, Guilin University of Electronic Technology, Guilin 541004, China.
⁵ Department of Physics, Faculty of Pure and Applied Science, Tsukuba Research Center for Energy Materials Science (TREMS), University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8576, Japan.
⁶ State Key Laboratory of Engines, Tianjin University, Tianjin 300072, China.
⁷ Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan.

Abstract

By the fine manipulation of the exceptional long-range germanium-telluride (Ge─Te) bonding through charge transfer engineering, we have achieved exceptional thermoelectric (TE) and mechanical properties in lead-free GeTe. This chemical bonding mechanism along with a semiordered zigzag nanostructure generates a notable increase of the average zT to a record value of ~1.73 in the temperature range of 323 to 773 K with ultrahigh maximum zT ~ 2.7. In addition, we significantly enhanced the Vickers microhardness numbers (H_v) to an extraordinarily high value of 247 H_v and effectively eliminated the thermal expansion fluctuation at the phase transition, which was problematic for application, by the present charge transfer engineering process and concomitant formation of microstructures. We further fabricated a single-leg TE generator and obtained a conversion efficiency of ~13.4% at the temperature difference of 463 K on a commercial instrument, which is located at the pinnacle of TE conversion.