A flexible n-type Ag₂Se thin film with a high power factor (PF) of 21.6 μW cm⁻¹ K⁻² and a ZT value over 0.6 was successfully prepared by a facile self-assembled growth method.

Flexible Sb₂Te₃-based thermoelectric (TE) materials are promising candidates for fabricating energy devices that power wearable electronics and sensors. Enhancing the TE properties of Sb₂Te₃ thin films represents a significant scientific investigation. In this work, a thermal diffusion method is applied to prepare the In-doped Sb₂Te₃ thin film. In doping can lead to a high Seebeck coefficient of ~137.04 μV K⁻¹ as well as moderate electrical conductivity. As a result, the high power factor of ~18.22 μW cm⁻¹ K⁻² at 303 K is achieved. Moreover, In doping could reduce the thermal conductivity owing to the increase in phonon scattering. Finally, the high ZT values of ~0.47 at room temperature (303 K) and ~0.6 at 453 K are obtained. This indicates that In doping is a highly promising and effective approach to improving the TE performance of Sb₂Te₃ thin films.

The Skutterudites CoSb₃ material has been the focus of research for the conversion applications of waste heat to electricity due to its ability to accommodate a large variety of ions in the cages that have been proven effective in improving the thermoelectric performance. Although the co-doped CoSb₃ bulk materials have attracted increasing attention and have been widely studied, co-doped CoSb₃ thin films have been rarely reported. In this work, Ag and Ti were co-doped into CoSb₃ thin films via a facile in situ growth method, and the influence of doping content in the thermoelectric properties was investigated. The results show that all the Ag and Ti co-doped CoSb₃ thin films contain a pure well-crystallized CoSb₃ phase. Compared to the un-doped thin film, the co-doped samples show simultaneous increase in the Seebeck coefficient and the electrical conductivity, leading to a distinctly enhanced power factor. The high power factor value can reach ~0.31 mWm⁻¹K⁻² at 623 K after appropriate co-doping, which is two times the value of the un-doped thin film we have been obtained. All the results show that the co-doping is efficient in optimizing the performance of the CoSb₃ thin films; the key point is to control the doping element content so as to obtain high thermoelectric properties.