磁控溅射沉积制备SnSe薄膜及其热电性能研究

因为晶体结构以及热电性能各向异性,硒化锡(SnSe)沿b轴方向表现出优异的热电性能,受到业内的广泛关注。但关于SnSe薄膜研究的报道较少。本研究利用磁控溅射技术,将SnSe沉积到Si/SiO₂基底得到SnSe薄膜,分析了沉积温度对SnSe薄膜结构和热电性能的影响。结果显示:沉积温度升高,晶粒尺寸相应增加,薄膜的结晶质量也随之提高。在573 K的沉积温度条件下,能获得高结晶质量和良好化学计量比的(111)取向SnSe薄膜,该薄膜具有约为1.25μW/(cm·K²)的最大功率因子(PF)。当沉积温度升高至773 K时,可以得到具有超高迁移率和赛贝克系数的(400)织构SnSe薄膜,该薄膜在573 K的测试温度下,其最大PF为0.5μW/(cm·K²),实现接近于文献报道的相同温度下单晶SnSe沿a轴的PF。本研究的结果证明了高沉积温度对SnSe薄膜微观结构和热电性能调控的重要性,并且为通过设计和调控SnSe基薄膜有序结构来提升其热电性能提供了新的研究思路。

Investigation on thermoelectric properties of SnSe thin films deposited by magnetron sputtering

Because of the anisotropy of the crystal structure and thermoelectric(TE)properties,tin selenide(SnSe)exhibits excellent thermoelectric properties along the b-axis and has received great attentions from the communities of science the industry.However,there are few reports on the SnSe thin films.In this study,magnetron sputtering technique is used to deposit SnSe films on a Si/SiO₂ substrate.The effect of deposition temperature on the structure and TE properties of the SnSe film is analyzed.The results show that with the temperature increases,both the grain size,and the crystal quality of the film increases.The(111)-textured SnSe film with high crystalline quality and good stoichiometric ratio is obtained under the deposition temperature of 573 K,which can obtain the maximum power factor(PF)of about 1.25μW/(cm·K²).In addition,when the temperature increases to 773 K,a(400)-textured SnSe film is obtained,which exhibits an ultra-high carrier mobility and Seebeck coefficient.The maximum PF is as high as 0.5μW/(cm·K²),at 573 K,which is close to value of single crystal SnSe along the a-axis at the similar temperature.Our results prove the importance of appropriate deposition temperature on the microstructure and TE properties of SnSe films and provide a new way for improving the TE properties of SnSe-based films by controlling the ordered microstructures.