Thermoelectric properties of rf-sputtered CoSb3 films

Film growth and electronic transport properties of CoSb/sub 3/ with the cubic skutterudite structure were studied. The skutterudite CoSb/sub 3/ films were successfully grown on Si(100) and quartz substrates by using a magnetron rf-sputtering. A preferential orientation growth along [310] plane occurs when the pressure of sputtering gas decreases. Polycrystalline films with the skutterudite structure are also obtained by annealing sputtered films at low temperature. Electrical conductivity of the films changes with the film growth conditions. Electronic structure of the films was investigated by X-ray photoelectron spectroscopy. Observed valence band structure agrees well with a recent band calculation. It is revealed that the valence band structure of CoSb, consists of the hybridized bands between Co d and Sb p states and a peak structure derived from localized Co d state.