Thermoelectric properties of bismuth telluride thin films deposited by radio frequency magnetron sputtering

This paper reports the thermoelectric properties of intrinsic N-type bismuth telluride (Bi2Te3) thin films (2.5 - 10 mu m thickness). These properties include; thickness). These films were deposited using radio frequency (R.F.) magnetron sputtering 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 mu V/degrees C and 4 x 10(-5) Omega m at room temperature, respectively. The maximum value of Seebeck coefficient of approximately -287 mu V/degrees C was observed at 54 degrees C for a film thickness of 9.8 mu m. 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 -rain size. The observed grain sizes were approximately 900 nm and 1500 nm for Bi2Te3 film of 2.6 pm and 9.8 mu m thicknesses, respectively. The XRD analysis indicated the presence of rhombohedral (Bi2Te3) crystal structures