<title>Thermoelectric properties of bismuth telluride thin films deposited by radio frequency magnetron sputtering</title>

Abstract

This paper reports the thermoelectric properties of intrinsic N-type bismuth telluride (Bi₂Te₃) thin films (2.5-10 μm thickness). These films were deposited using radio frequency (R.F.) magnetron sputtering. These properties include; Seebeck coefficient and electrical resistivity at different temperatures. It has been observed that the Seebeck coefficient and electrical resistivity of thin films are approximately -150 μV/°C and 4 x 10^-5 ohm-m at room temperature, respectively. The maximum value of Seebeck coefficient of approximately -287 μV/°C was observed at 54 °C for a film thickness of 9.8 μm. The microstructural characteristics of the thin films were investigated using Scanning Electron Microscopy and X-Ray Diffraction analysis. It was observed that the thicker the Bi₂Te₃ film, the larger the grain size. The observed grain sizes were approximately 900 nm and 1500 nm for Bi₂Te₃ film of 2.6 μm and 9.8 μm thicknesses, respectively. The XRD analysis indicated the presence of rhombohedral (Bi₂Te₃) crystal structures.