磁控溅射法制备Bi2Te3热电薄膜的研究

Bi2Te3薄膜是室温下热电性能最好的热电材料,利用磁控溅射在长有一薄层SiO2的n型硅样品上制备Bi/Te多层复合薄膜,经后续退火处理生成Bi2Te3。通过分析Bi2Te3薄膜的生长和退火工艺,探讨Bi/Te中Te的原子数分数对薄膜热电性能的影响。采用XRD和SEM对薄膜的结构、形貌和成分进行分析,并测量不同条件下的Seebeck系数。薄膜Seebeck系数均为负数,表明所制备样品是n型半导体薄膜,且最大值达到-76.81μV.K-1;电阻率ρ随Te的原子数分数增大而增大,其趋势先缓慢后迅速。Bi2Te3薄膜的热电性能良好,Te的原子数分数是60.52%时,功率因子最大,为1.765×10-4W.K-2.m-1。

Study on Bi2Te3 Thermoelectric Thin Films Fabricated by Magnetron Sputtering

Bi2Te3 thin films are thermoelectric materials,which have the best thermoelectric properties at room temperature.Bi/Te multilayer films were prepared on SiO2/Si substrates by magnetron sputtering,which can generate Bi2Te3 films with the subsequent annealing.The Te contents of the Bi2Te3 films as a function of thermoelectric performance were investigated.The structures,morphology and composition of films were characterized by X-ray diffraction,field emission scanning electron microscope,and measure the Seebeck coefficient under different conditions.Seebeck coefficient of thin films were negative,which indicate that the prepared samples were all n-type semiconductor films,and the maximum Seebeck coefficient was-76.81μV·K-1.The resistivity ρ increased with Te content,the trend was slow at first than quick.Bi2Te3 thin films have good performance.The maximum power factor of the thin films is 1.765×10-4W·K-2·m-1 when Te atomic percentage content is 60.52%.