Abstract: Skutterudite-based CoSb₃ materials have attracted significant attention in thermoelectric applications due to their environmental friendliness, thermal stability, and excellent thermoelectric properties. While considerable progress has been made in the development of n-type skutterudite thermoelectric thin films, research on high-performance p-type filled skutterudite flexible thin films remains limited, particularly in the context of flexible device integration. In this work, p-type Ce_0.9Fe₃CoSb₁₂ thin films were deposited on glass substrates via radio frequency magnetron sputtering, and the influence of sputtering power (100-120 W) on the film composition, microstructure, and thermoelectric properties was systematically investigated. The results reveal that increasing the sputtering power leads to a gradual decrease in the Ce/Fe atomic ratio and a corresponding increase in hole concentration, which enhances the electrical conductivity (σ) but reduces the Seebeck coefficient (S). The film deposited at 110 W exhibited the highest thermoelectric performance, achieving a power factor (PF) of 76.7 μW·m^-1∙K^-2 at room temperature and reaching 103.5 μW·m^-1∙K^-2 at 500 K. Building upon these findings, flexible Ce_0.9Fe₃CoSb₁₂ films were further fabricated on polyimide (PI) substrates with substrate heating applied during deposition to improve interfacial adhesion. A flexible thin-film thermoelectric generator was successfully integrated, and its potential application in temperature sensing was evaluated. The device demonstrated excellent mechanical flexibility and reliable thermal sensing performance, highlighting its promise for use in flexible thermoelectric sensor technologies.

Key words: thermoelectric, CoSb₃, thin film, magnetron sputtering, thermoelectric sensor