TY  - JOUR
AU  - Ning, Xingkun
AU  - Ran, Yongmao
AU  - Han, Jiaying
AU  - Gao, Linjie
AU  - Wang, Shufang
PY  - 2026
TI  - Remarkable flexibility and curvature-tunable thermoelectric properties in transparent freestanding single-crystalline CdO membranes
JO  - Journal of Materiomics
SN  - 2352-8478
VL  - 12
IS  - 2
AB  - Transparent thermoelectric CdO thin films exhibit critical flexibility and thermoelectric performance that require focused research to advance flexible transparent self-powered devices. Here, we demonstrate the superior flexibility of freestanding single-crystalline CdO membranes. These membranes achieve a notable room-temperature power factor of 1.48 μW·cm−1·K−2 and exhibit superior optical transmittance exceeding 94% in the 550–800 nm range. Crucially, freestanding CdO exhibits exceptional mechanical robustness, retaining >90% electrical conductivity after 1000 bending cycles (radius: 11.5 mm). Microstructure analyses confirm polycrystalline CdO films suffer from grain boundary cracking under bending due to stress concentration, but single-crystal CdO membranes—without grain boundaries to concentrate stress—exhibit better flexibility and resistance to cracking. Furthermore, curvature-induced strain boosts the power factor by 12.8%, providing a curvature-controlled strain engineering strategy to optimize flexible thermoelectric performance. This work establishes freestanding CdO as a highly efficient and flexible thermoelectric material and suggests a fundamental strategy for designing robust smart materials for transparent, self-powered flexible electronics.
UR  - https://doi.org/10.1016/j.jmat.2025.101153
DO  - 10.1016/j.jmat.2025.101153