Enhancement of the thermoelectric performance of (BiSb)2Te3 films by single target sputtering

Abstract

In this study, (BiSb)2Te3 thin films were deposited onto glass substrates at a temperature of 300 °C, utilizing radio frequency (RF) sputtering across a range of growth conditions. The primary focus of this investigation was to analyzse the effects of varying RF power, chamber gas pressure, and annealing temperature on the thermoelectric properties of the films, deposited by an exclusively-made single target.Notably, it was observed that increasing the annealing temperature significantly boosted both the deposition rate and grain size. Through carefully optimizsing growth conditions and subsequent annealing procedures, it was discerned that thin films cultivated at higher RF power levels exhibited markedly improved electrical conductivity, attributed to a discernible rise in carrier concentration. Furthermore, films generated under the RF power of 37.5 W showed a noteworthy augmentation in the Seebeck coefficient, recording approximately 147 μV/K. This enhancement in Seebeck coefficient correlated with the attainment of the highest power factor, reaching an impressive 220.57 μW/mK2.