The Photoelectric Properties Of Sn-Al Co-doped ZnO Thin Films Prepared By Sol-gel Process And Spin-coating

Transparent conductive thin films are widely used in liquid crystal displays,transparent electrode solar cells and various photoelectric devices because of their good photoelectric properties.Transparent conductive oxide films are widely used.However,because of its toxic and expensive price,ITO film limits its application.Because of its own advantages,ZnO based films have been studied by researchers,and the purpose of replacing ITO films has been achieved.Zinc Oxide(Zinc oxide,short for short)is a metal oxide with six angle zinite structure.Room temperature with band gap is a direct band gap of 3.37 eV.ZnO of the exciton binding energy is relatively high(about 60 meV),stable performance,not easy to react with other substances,has been applied in optoelectronic devices.So it has been a hot topic of excellent synthesis to choose the appropriate preparation method of ZnO thin films.In this thesis,intrinsic ZnO thin films using ethylene glycol monomethyl ether as the solvent and zinc acetate as the precursor for the system,Al doped ZnO thin films and Sn-Al Co-doped ZnO thin films using nine hydrated aluminum nitrate and crystallization of four tin chloride as the doping agent to provide Al and Sn sources,ethanolamine as preparation of colloidal stabilizer,were successfully prepared on substrate by sol-gel technique adopting spin coating process after heat treatment.Through the study of the preparation conditions of the intrinsic ZnO,the optimum parameters to prepare ZnO thin films were pre-treatment temperature of 180? and the substrate of Si.The lattice parameters,structure and crystal quality,microstructure,photoluminescence and transmission properties were investigated by X-ray diffraction(XRD),scanning electron microscopy(SEM),photoluminescence(PL)spectrum and ultraviolet visible spectrophotometer(UV-vis).The results show that:(1)introducing two elements of Al and Sn into ZnO thin films,without changing the lattice structure of the films,have a certain effect on the preferred orientation of C axis of the films,and the grain size of the films change.(2)Al doped ZnO thin films have better preferred orientation,smaller grain size,wider band gap,smooth surface and more than 90%transmittance of the thin films.(3)Sn-Al Co-doped ZnO films.The incorporation of Sn improves the photoelectric properties of the films,and makes the transmittance of the film further improved and the electrical properties are better.