| Summary: | 碩士 === 國立臺灣大學 === 材料科學與工程學研究所 === 101 === Bismuth telluride-based compound is currently widely used in thermoelectric material due to its excellent thermoelectric performance around room temperature. By doping different elements, P-type Bi0.5Sb1.5Te3 and N-type Bi2Te2.7Se0.3 can be made. The thermoelectric thin films of Bi0.5Sb1.5Te3 and Bi2Te2.7Se0.3 on polyimide substrates are prepared by radio-frequency (RF) magnetron sputtering. The Bi0.5Sb1.5Te3 and Bi2Te2.7Se0.3 thin films are deposited with different substrate temperature, work pressure and RF power by radio-frequency (RF) magnetron sputtering. Finally, this research analyses the themoeleletric performance, crystal structure and composition by XRD, XPS, Hall effect and the Seebeck effect.
This research discovers that the P-type Bi0.5Sb1.5Te3 thermoelectric thin films show the best thermoelectric properties at room temperature with 18 Watts of RF working pressure under 5 mTorrs after electrical annealing treatment at 270 degrees Celsius for 5 minutes；The Seebeck coefficient is 220.5 μV/K, the lowest electrical resistivity is 5 mΩ∙cm, and the highest power factor is 9.59 μW/K2cm.
N-type Bi2Te2.7Se0.3 thermoelectric thin films show the best thermoelectric properties at room temperature with 15 Watts of RF, working pressure under 5 mTorrs after electrical annealing treatment at 270 degrees Celsius for 5 minutes and the Seebeck coefficient is 177.65 μV/K,the lowest electrical resistivity is 3.264x10-2 Ω∙cm and the highest power factor is 4.158 μW/K2cm.
|
|---|
