Photoelectric Properties Of Ti Doped SnO₂ Thin Films Prepared By Sol-gel Method

Nowadays,transparent and electrical conductive oxide（TCO）thin film is an important part of all kinds of photoelectric devices.Stannic oxide（SnO₂ ）has a wide band gap,high conductivity,high transmittance and abundant reserves,so it has a rich application in modern technology development.At present,it is very important to prepare SnO₂ film with excellent performance at low cost to improve the performance of TCO materials.In this thesis,SnO₂ films prepared by Sol-gel spin coating method（Sol-gel method）were studied,and the photoelectric properties of SnO₂ films were improved by changing process parameters and doping metal elements.The structure,morphology,optical and electrical properties of the film was analyzed in detail with the X-ray diffractometer（XRD）,X-ray photoelectron spectrometer（XPS）,field emission scanning electron microscope（FESEM）,atomic force microscope（AFM）,film thickness measuring instrument,ultraviolet-visible spectrophotometer（UV-Vis）,fluorescence spectrometer and hall effect tester.The research and analysis results are as follows:（1）The intrinsic SnO₂ films at different annealing temperatures were studied.When the annealing temperature is 600℃,SnO₂ films have the best crystal quality,the highest optical transmittance and the lowest resistivity,and the overall good photoelectric performance.（2）The intrinsic SnO₂ films with different sol concentrations were studied.The optimal sol concentration is 0.7 mol/L,and the highest optical transmittance of the film can reach about 94.0%.（3）The intrinsic SnO₂ films with different numbers of spin coatings were studied.In the sample with 3-9 layers,when the number of spin-coating layers is 5,the film thickness is moderate,the surface is smooth and dense,and the optical transmittance is the highest.（4）Ti doped SnO₂ films with different Ti doping concentrations were studied.When Ti doping concentration is 5 at%,the figure of merit（FOM）in doped samples can reach14.59×10^-3Ω^-1,and the sample has excellent photoelectric properties.