Optimized weighted mobility induced high thermoelectric performance of ZnO‐based multilayered thin films

• Published in: Journal of the American Ceramic Society Vol. 106; no. 5; pp. 2911 - 2917
• Main Authors: Zhou, Zhifang, Zheng, Yunpeng, Yang, Yueyang, Zhang, Wenyu, Wei, Bin, Zou, Mingchu, Lan, Jinle, Nan, Ce‐Wen, Lin, Yuan‐Hua
• Format: Journal Article
• Language: English
• Published: Columbus Wiley Subscription Services, Inc 01.05.2023
• Subjects: Band structure of solids; Carrier transport; Electrical properties; electrical transport property; Electron transport; Gallium; Integrated circuits; multilayer interface; Multilayered thin films; Optimization; Power factor; thermoelectric; Thermoelectricity; Thin films; Transport properties; weighted mobility; Zinc oxide; Zinc oxides; ZnO thin films
• ISSN: 0002-7820; 1551-2916
• DOI: 10.1111/jace.18950

As a transparent thermoelectric oxide, gallium‐doped zinc oxide (GZO) has the potential to power wearable or portable electronics and may be used in the integrated circuits industry for chip cooling. Constructing ZnO–GZO interfaces has been proposed as an effective strategy for improving thermoelectric performance of GZO thin films. However, without the aid of band structure calculation for multilayered films, it is hard to directly elucidate the underlying mechanisms of carrier transport. Weighted mobility is an indicator that reveals the inherent electronic transport properties like carrier scattering, electronic band structure, and so on. Thus, to further investigate the effects of ZnO–GZO interfaces on electrical properties of GZO thin films, the structures containing different numbers of ZnO–GZO interfaces were designed and the correlations among numbers of ZnO–GZO interfaces, weighted mobility, and electrical properties were explored. It was found that with more ZnO–GZO interfaces, the weighted mobility increased, and the power factor values also improved as well. Consequently, an enhanced power factor value reached 439 μW m−1 K−2 at 623 K. This work demonstrated the beneficial effects of multiple interfaces on the improvements of electrical transport performance through analyzing weighted mobility, which laid a foundation for further optimization of thermoelectric performance.