Studies On The Photoelectric And Auti-reductive Properties Of TiO₂/FTO Bilayer Films

FTO glass has good photoelectric performance and durability,so is often used as the electrode in making thin film solar cells.There is a photoelectric performance deterioration because of the existence of hydrogen plasma during the deposition process of semiconductor layer.In this article,tetrabutyl titanate was use as the precursor to deposite TiO₂ layer films on the top of textured FTO glass using the spray pyrolysis technique.Different TiO₂/FTO bilayer films were obtained by adjusting the temperature of substrate,deposition time and the concentration of Ti4+.The phase and crystalline structure of bilayer film was characterized by an X-ray diffractometer?XRD?.The morphology,film thickness and surface roughness were studied by field-emission scanning electron microscopy?FESEM?and atomic force microscope?AFM?.The haze value and transmittance were studied by haze meter and UV-Vis spectrophotometer.Glow discharge spectrometer was used to analysis the distribution of element.There is a serious deterioration on the photoelectric performance of the as-deposited FTO film after hydrogen plasma treatment with the average transmittance in visible light range decreased from 64.5% to 34.5%,sheet resistance deteriorated from 55.20 ?/? to 15.07 ?/?,While TiO₂ film can cover the FTO surface uniformly,there is an obvious improvement for the protection of TiO₂/FTO film.With the increase of the substrate temperature and the spraying time,the thickness of TiO₂ film and the haze of bilayer film increase.The anti-reductive performance to hydrogen plasma increases.The haze of bilayer film increases at first and then decreases with the increase of Ti4+ concentration,and the anti-reductive to hydrogen plasma become stronger gradually.When the substrate temperature is 400 ?,the spraying time is 3 min and the concentration of Ti4+ is 0.2 mol/L,the properties of the substrate are better,and it can resist the hydrogen plasma bombardment.While the thickness is 212.6 nm,the average transmittance is 51.2% and the haze is 36.71%.After H₂ plasma treatment,the transmittance and haze were changed by-5.13% and +6.6%,respectively.