Inducing High Power Factor in Cu2GeSe3-Based Bulk Materials via (Bi, Zn)-Co-doping

作者：Hu, Zeqing; Wei, Rong; Yan, Chen; Wan, Han; Liu, Yu; Cheng, Longjiu; Li, Zhou; Song, Jiming^*

来源：ACS Applied Energy Materials, 2023, 6(5): 2962-2972.

DOI：10.1021/acsaem.2c04012

• Cu2GeSe3
• power factor
• figure of merit ZT
• (Bi
• Zn)-co-doped
• solid-state reaction

In this work, carrier concentration optimization and effective mass increase of Cu2GeSe3 , which were considered to be a synergetic effect of electrical transport properties, were achieved by the co-doping of Bi and Zn on the Cu site. This effect led to a higher Seebeck coefficient of - ,307.76 mu V K-1at 723 K for the Cu1.988Bi0.01Zn0.002GeSe3 sample. This effect also resulted in a higher power factor of - ,8.66 mu W cm-1 K-2 at 723 K and an average power factor of - ,6.29 mu W cm-1 K-2 at the temperature range of 303- 723 K for the Cu1.988Bi0.01Zn0.002GeSe3 sample, which were - ,135 and - ,196% larger than those of pristine Cu2GeSe3 , respectively, and are among the highest value of the Cu2GeSe3-based sample. Benefiting from simultaneous optimization of the power factor, the maximum ZT of - ,0.75 for the Cu1.988Bi0.01Zn0.002GeSe3 sample at 723 K was obtained, which is - ,288% higher than that of Cu2GeSe3.