退火处理对室温制备Bi0.5Sb1.5Te3薄膜热电性质的影响研究
Study of the effect of annealing treatment on thermoelectric properties of Bi0.5Sb1.5Te3 thin films prepared at room temperature
娄本浊
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作者单位:陕西理工学院
中文关键字:Bi0.5Sb1.5Te3薄膜;退火处理;热电性质
英文关键字:Bi0.5Sb1.5Te3 thin film; annealing treatment; thermoelectric property
中文摘要:Bi0.5Sb1.5Te3材料是目前室温下最佳的P型热电材料。本文利用射频磁控溅镀法在SiO2/Si基板上制备了Bi0.5Sb1.5Te3薄膜样品,并且测量了薄膜样品在不同退火时间与退火温度下的热电性质。实验结果表明,薄膜样品经30h退火后的热电性质与1h退火后的热电性质相差不大,这说明长时间退火并不是Bi0.5Sb1.5Te3薄膜的最佳退火时间。而在不同退火温度下,样品的塞贝克系数在2750C~3000C的退火温度范围内下降比较快,当退火温度为3000C时降至最小,约为181μV/K;而其电阻率则随退火温度的升高呈现出先减小后增大的趋势,退火温度为2250C时具有最小的电阻率约为6.1mΩ.cm。最后本文得出经2250C退火10mins后可得到最佳的热电性质,即薄膜样品的的塞贝克系数为208μV/K,电阻率为6.1mΩ.cm,功率因子则为6.9×10-4W/m.K2。
英文摘要: The material of Bi0.5Sb1.5Te3 is known to be the best P-type thermoelectric material at the room temperature. In this paper, the Bi0.5Sb1.5Te3 thin films are prepared by the magnetron sputter deposition method and the thermoelectric properties of these films are measured at different annealing times and annealing temperatures. The experimental results show that the thermoelectric properties of Bi0.5Sb1.5Te3 thin films differ little at annealing times of 30 hours and 1 hour, which reveals that a long annealing time is not suitable for Bi0.5Sb1.5Te3 thin films. At different annealing temperatures, the Seebeck coefficient of sample decreases rapidly during the annealing temperature range of 2750C~3000C and its minimum value is of about 181μV/K. The electrical resistivity of sample first increases and then decreases with the annealing temperature and its minimum value is of about 6.1mΩ.cm at the annealing temperature of 2250C. It is found that the Bi0.5Sb1.5Te3 thin film has a moderately reduced Seebeck coefficient of 208μV/K and the lowesr resistivity of 6.1mΩ.cm, leading to the highest power factor of 6.9×10-4W/m.K2 after annealing at 2250C for 10 minutes.