The Effect Of PEG-200 On The Photoelectric Of SnO₂:F Thin Film

SnO₂:F film is widely used in low-emissivity（Low-e）glass,solar cells and other fields because of the excellent electrical conductivity and transparency.Spray pyrolysis is widely used in preparing the coatings with great binding force.By spray pyrolysis,the SnO₂:F films with excellent optoelectronic properties can be expected.The chemical composition of spraying liquid is very important in determining the property during the process of spray pyrolysis SnO₂:F film.In this paper,SnCl4·5H2O is used as the Sn source,HF is used as a dopant,industrial alcohol is uesd as solvent and PEG-200 is ued as an additive to prepare the SnO₂:F sol,and the impact of PEG-200 additives on SnO₂:F thin-film photovoltaic performance is studied The application prospects of prepared SnO₂:F film in Low-e glass and solar cell fields is also discussed,specific research and conclusions are as follows:（1）Five groups of SnO₂:F film with the deposition temperature of 520℃,the spray solution without PEG-200 and the added amount of 0.5wt%,1.0wt%,2.0wt%and 3.0wt%prepared by spray pyrolysis were studid.The results showed that:PEG-200 added has a significant effect on the film thickness,grain size,degree of crystallinity and the surface roughness.With the increase of PEG-200（0.5wt%～3.0wt%）,the film thickness,SnO₂ grains and the surface roughness increases,the degree of crystallinity of the film becomes better.（2）The impact of the amount of PEG-200 on SnO₂:F thin-film photoelectric performance was studied.The resistivity of the film reduced significantly when the amount increased from 0.0wt%to 1.0wt%,from 7.92 ×10^-4Ω·cm reduced to 5.04 ×10^-4 Ω · cm,compared with film without PEG-200,decreased by 36.4%;and the resistivity of the film slightly increased when the amount of PEG-200 increased from 1.0wt%to 3.0wt%.（3）The film resistance reduced to minimum when the amount was 1.0wt%,with the increase in the amount of PEG-200（0.5wt%～3.0wt%）,the average visible light transmittance of the film decreased gradually,the haze increased gradually,hemispherical emissivity decreased.the best optical performance was obtained when the amount was 1.0wt%,the film resistivity,average visible light transmittance,haze and hemispherical emissivity was 5.04 ×10^-4 Ω· cm,77.20%,8.77%and 0.10,respectively.On this basis,the impacts of the deposition temperature and film thickness on the photoelectric performance of the SnO₂:F thin-film prepared by spray pyrolysis were studied,when the amount of PEG-200 was 1.0wt%.When the deposition temperature was 535℃,the film thickness was 560nm,the film resistivity and hemispherical radiation rate reached to the lowest values,5.04 x 10-4Ω·cm and 0.12,respectively.Meet the basic requirements of the Low-e glass.（4）The film haze increase with the increase in the amount of PEG-200（0.5wt%～3.0wt%）,when the amont of PEG-200 was 1.0wt%,the film haze was 8.77%,when the amont of PEG was more than 2.0wt%,the haze increased greatly,the largest haze was obtained when the amount was 3.0wt%.But at this time,the film surface defects,average resistivity and visible light transmittance was worse compared to the amount of 1.0wt%.As a result,the sol with 1.0 wt%PEG-200 was chosen to the preparation of different deposition temperature and film thickness of SnO₂:F films.Under the process conditions of deposition temperature 535℃,film thickness 360nm,the resistivity of the average visible light transmittance and haze of the SnO₂:F film prepared was 5.04 ×10^-4 Ω· cm,74.62%and 9.6%,respectively.Optical properties of the film was close to the basic requirements of the conductive substrate for solar cells.