Microstructures and thermoelectric properties of p-type BixSb2−xTe3 thin films with various compositions

In the present study, p-type BixSb2−xTe3 thermoelectric thin films with various chemical compositions were fabricated by a magnetron co-sputtering process. The influence of Bi content (x) on the microstructures and thermoelectric properties of BixSb2−xTe3 films was investigated. It was found that the grain size of nanocrystalline BixSb2−xTe3 films decreased when increasing the Bi content from x = 0 to x = 0.57, which resulted in a concurrent decrease in the carrier mobility. Similarly, carrier concentration decreased with increasing Bi content, which caused an increase in the Seebeck coefficient. The largest room-temperature power factor reached 31.3 µWK−2cm−1 for the film with x = 0.45.