Directional Thermal Diffusion Realizing Inorganic Sb 2 Te 3 /Te Hybrid Thin Films with High Thermoelectric Performance and Flexibility

• Published in: Advanced functional materials 2022-11, Vol.32 (45)
• Main Authors: Wei, Meng, Shi, Xiao‐Lei, Zheng, Zhuang‐Hao, Li, Fu, Liu, Wei‐Di, Xiang, Li‐Ping, Xie, Yang‐Su, Chen, Yue‐Xing, Duan, Jing‐Yi, Ma, Hong‐Li, Liang, Guang‐Xing, Zhang, Xiang‐Hua, Fan, Ping, Chen, Zhi‐Gang
• Format: Article
• Language: English
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202207903

Inorganic films possess much higher thermoelectric performance than their organic counterparts, but their poor flexibilities limit their practical applications. Here, Sb 2 Te 3 /Te x hybrid thin films with high thermoelectric performance and flexibility, fabricated via a novel directional thermal diffusion reaction growth method are reported. The directional thermal diffusion enables rationally tuning the Te content in Sb 2 Te 3 , which optimizes the carrier density and leads to a significantly enhanced power factor of > 20 µW cm –1  K –2 , confirmed by both first‐principles calculations and experiments; while dense boundaries between Te and Sb 2 Te 3 nanophases, contribute to the low thermal conductivity of ≈0.86 W m –1  K –1 , both induce a high ZT of ≈1 in (Sb 2 Te 3 )(Te) 1.5 at 453 K, ranking as the top value among the reported flexible films. Besides, thin films also exhibit extraordinary flexibility. A rationally designed flexible device composed of (Sb 2 Te 3 )(Te) 1.5 thin films as p ‐type legs and Bi 2 Te 3 thin films as n ‐type legs shows a high power density of > 280 µW cm –2 at a temperature difference of 20 K, indicating a great potential for sustainably charging low‐power electronics.