氮掺杂SiC厚膜的制备及其热电特性

Deposition and Thermoelectric Properties of N-Doped SiC Thick Films

以 Si C超细粉为原料 ,采用热等离子体 PVD(TPPVD)法快速制备了 Si C膜 ,最大沉积速度达到 1 38nm /s.为了降低 Si C膜的电阻率 ,提高其热电性能 ,采用向等离子体中通入 N2 的方法对 Si C膜进行了掺杂 .用扫描电子显微镜、X射线衍射和 X射线光电子谱对薄膜的形貌和结构进行了观察和分析 .实验测定了 Si C膜掺杂前后的热电性能并与 Si C烧结体的结果进行比较 .实验结果表明 :向等离子体中导入 N2 是对 Si C膜进行掺杂的有效方法 ,但同时也显著影响 Si C膜的形貌、成分和沉积速度 .未进行氮掺杂和经过氮掺杂后的 Si C薄膜的 (S2 /ρ)值在 973K时分别达到 1 6 0 μW/(m· K2 )和 1 0 0 0 μW/(m· K2 ) ,是 Si C烧结体的 5 .3倍和

Silicon carbide thick films were deposited by thermal plasma PVD with SiC ultrafine powder as a starting material at the maximum deposition rate of 138nm/s.In order to lower the electrical resistivity and improve the thermoelectric properties,the SiC thick films were doped with nitrogen by injection of N 2 as plasma gas.By using SEM,XRD and XPS the morphologies were observed and their microstructures were analyzed.The thermoelectric properties of the undoped and N doped films were measured in comparison with that of sintered SiC.Experimental results showed that it is an effective N doping way for SiC films by injection of N 2 as plasma gas,however,it also has significant influence on the morphology,composition and deposition rate.The power factor ( S 2/ρ ) of the undoped and N doped films at 973K reached 160μW/ (m·K 2) and 1000μW/ (m·K 2) ,which are 5 3 and 33 times that of sintered SiC,respectively.