Defect engineering can effectively modulate the band structure of a thermoelectric (TE) material, thereby enhancing its power factor S2σ. Furthermore, residual stress engineering influences the film performance, especially in the planar technologies. For the TE Mg-doped CuCrO2-based materials, the limitations in achieving an outstanding figure of merit, ZT, arise from their characteristically low charge carrier mobility and high thermal conductivity. Herein, we propose a combination of defect engineering and stress engineering via heavy doping CuCr1-xMgxO2 with × = 0.15 at different deposition temperatures to overcome the aforementioned limitations. Combining the compressive residual stress with multiscale defects (point defects, grain boundaries, and nano-inclusions) significantly reduces the thermal conductivity (κ) to 0.44 W/mK. The σ of the films shows a remarkable enhancement because of point defects introduced via heavy doping. Notably, the compressive-stressed films exhibit higher ZT values, compared to the tensile-stressed films. As a result, an outstanding approximated ZT of 0.66 is observed in the compressive-stressed CuCr0.85Mg0.15O2 films, overcoming the limitations of its ZT value observed for the past two decades.
|Journal||Applied Surface Science|
|Publication status||Published - 2022 May 1|
Bibliographical noteFunding Information:
Hoang Van Dung was funded by Vingroup Joint Stock Company and supported by the Domestic Master/PhD Scholarship Programme of Vingroup Innovation Foundation (VINIF), Vingroup Big Data Institute (VINBIGDATA), code VINIF.2020.TS.50. Takao Mori, Takahiro Baba, and Isao Ohkubo acknowledge support from JST Mirai Program Grant Number JPMJMI19A1. Thang Bach Phan acknowledges support from the Vietnam Ministry of Science and Technology under grant number ÐTÐL.CN-23/18 and the Vietnam National University, Ho Chi Minh City under grant number TX2022-50-01.
© 2022 Elsevier B.V.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Physics and Astronomy(all)
- Surfaces and Interfaces
- Surfaces, Coatings and Films