High-performance In filled CoSb3 nano thin films fabricated by multi-step co-sputtering method

In filled CoSb3 thin films with various In content were prepared on flexible substrates by multi-step co-sputtering method, which provided a promising way to prepare low-cost and high performance thin films. The influence of In content on the microstructure and thermoelectric properties of the CoSb3 based thin films are systematically investigated. The thin film transforms from P-type to N-type with the increasing of In content. Both of the electrical conductivity and the Seebeck coefficient of the thin films increase after In filled. The thermal conductivity of the In filled thin film significantly decreases and the ZT value of the In-filled thin films are much higher than that of the unfilled thin film. It can be observed that the In filled thin films are single CoSb3 phase and the grain size increases after In filled. The average grain size of all the thin films are less than 50 nm, indicates the thin films are nano-particles structure.