掺杂剂对SnO2基导电膜性能的影响

Effects of different dopants on properties of SnO2-based conductive films

以SnCl4·5H2O和SnCl2·2H2O为Sn源,分别以SnF2、SbCl3和La(NO3)3·6H2O为掺杂剂,采用溶胶−凝胶−气相沉积法制备了SnO2基导电膜,主要研究掺杂剂的掺入对薄膜的表面形貌、微观晶体结构及光电性能的影响,探讨其掺杂机理。通过四探针电阻率/方阻测试仪、双光束紫外可见分光光度计、扫描电子显微镜、X射线粉末衍射仪和X射线光电子能谱分析系统等设备对SnO2基导电膜进行测试分析。结果表明:采用3种掺杂剂制备的SnO2基导电膜均为四方金红石结构,其表面形貌分别为金字塔状、贝壳状以及不规则多面体状。其中SnO2:Sb导电膜的性能最好,当以掺杂量为12%(摩尔比)的SbCl3为掺杂剂时,SnO2基导电膜的电阻率为1.36×10^−3Ω·cm,透射率为78.9%,综合光电性能指数为61.87×10^−4Ω−1。另外,不同掺杂元素的掺杂类型不同,对能级结构、晶胞结构、表面形貌、综合光电性能的影响也不同,且n型掺杂剂改性效果优于p型掺杂剂。

The SnO2-based films were prepared by a self-innovative sol-gel-vapor deposition method,taking F,Sb and La as the dopant of the representative of non-metallic,metalloid,and rare earth elements,respectively.SnO2-based films were tested and analyzed using four-probe resistivity/square resistance tester,dual-beam ultraviolet-visible spectrophotometer,scanning electron microscopy,X-ray powder diffractometer,and X-ray photoelectron spectroscopy.The surface morphology,microcrystalline structure and photoelectric properties of SnO2-based films with different dopants were studied,and their mechanism was discussed.The results show that the doped SnO2 films all are tetragonal rutile phase,and the surface morphologies of the SnO2 films with SnF2,SbCl3 and La(NO3)3·6H2O doped are pyramidal,shell-like and irregular polyhedrons,respectively.The resistivity of SnO2-based film is 1.36×10^−3Ω·cm,the transmittance is 78.9%,and the comprehensive photoelectric property is 61.87×10^−4Ω^−1 when the dopant is 12%(mole ratio)SbCl3,and its properties are the best of all samples.The difference in energy level structure,microstructure,surface morphology and photoelectric properties of SnO2-based films is mainly attributed to the different doping types of different dopants.And the modification effect of n-type dopants is better than that of p-type dopants.