溶胶-凝胶法制备SnO2:Ti薄膜的光电性能研究

Study on photoelectric properties of SnO2:Ti thin films prepared by sol-gel method

摘要:

为了克服二氧化锡(stannic oxide,SnO₂)薄膜材料电导率低、透过率有限的缺点,通过掺杂改性的方式得到光电性能更佳的SnO₂薄膜。以无水乙醇作为溶剂,采用溶胶-凝胶(soliquid-gelatum,sol-gel)法制备出了Ti掺杂分别为0 at%、3 at%、5 at%、7 at%、9 at%的SnO₂薄膜。并利用X射线衍射仪(X-ray diffractometer,XRD)、 X射线光电子能谱(X-ray photoelectron spectroscopy,XPS)、 扫描电子显微镜(scanning electron microscope,SEM)、原子力显微镜(atomic force microscope,AFM)、紫外-可见(ultraviolet-visible,UV-Vis)分光光度计和霍尔效应测试仪对Ti掺杂的SnO₂薄膜的结构、形貌和光电性能进行研究。结果表明,除Ti掺杂量为9 at%以外,其余样品透过率都达到90%以上,光学带隙值随着掺杂浓度的升高呈现先减小后增大的趋势。另外,Ti掺杂使SnO₂薄膜的电阻率降低,当Ti掺杂量为3 at%时,其样品品质因数(figure of merit,FOM) 最高可达到14.45×10-3 Ω-1。

Abstract:

In order to overcome the shortcomings of stannic oxide (SnO₂) film material with low conductivity and limited transmittance,SnO₂ film with better photoelectric properties was obtained by doping modification.SnO₂ films doped with Ti were prepared by soliquid-gelatum(sol-gel) spin coating method using anhydrous ethanol as solvent,which were 0 at%,3 at%,5 at%,7 at% and 9 at%,respectively.The structure,morphology and photoelectric properties of Ti doped SnO₂ thin films were systematically analyzed by X-ray diffractometer (XRD),X-ray photoelectron spectroscopy (XPS),scanning electron microscope (SEM),atomic force microscope (AFM),ultraviolet-visible (UV-Vis) spectrophotometer and Hall effect tester.The results show that the transmittance of the samples is above 90% except for Ti doping of 9 at%.The optical band gap values first decrease and then increase with the increase of doping concentration.In addition,Ti doping reduces the resistivity of SnO₂ films,and the highest figure of merit (FOM) of the samples can reach 14.45×10-3 Ω-1 when the Ti doping amount is 3 at%.