Preparation And Research Of TiO₂ Photoanode In Dye-sensitized Solar Cells

Nanocrystalline dye-sensitized solar cells(DSSC)have attracted extensive attention by domestic and foreign scientific researchers due to low-cost,simple technique,rich raw materials etc.At present,the photoelectric conversion efficiency of DSSC is still far lower than the theoretical value.As the important component of DSSC,the performance of photoanode will directly affect the photoelectric conversion efficiency of DSSC.Different kinds of TiO2 photoanodes were prepared and the performance of DSSC was studied.The research includes:(1)Ti02 nanopowders prepared via non-hydrolytic sol-gel method were applied as photoanode material in DSSC.TiO2 dense layer was prepared on conductive glass through dipping method and the effect of dense layer on the photoelectric performance of DSSC was studied;(2)TiO2 nanotubes prepared via template method and hot alkali treatment method were applied as photoanode material in DSSC;(3)TiO2 nanoballs power was prepared via template method by using ZnO nanoballs power prepared through hydrothermal method as templates and then applied it in the DSSC.The results are as following:(1)TiO2 nanoparticles power was prepared via non-hydrolytic sol-gel method.TiO2 nanoparticles were obtained with diameters of 15-35nm.TiO2 was anatase phase when the calcination temperature was lower than 700℃.TiO2 photoanode film with different calcination temperatures and holding time were prepared and then assembled into DSSCs.The performance of the DSSC with TiO2 film sintered at 450℃ for 15 min was optimal,showing a photoelectric conversion efficiency of 6.83%.The short-circuit photocurrent the open-circuit voltage and the fill factor were 15.38 mA cm-2,0.71V and 0.62,respectively.Titanium sol was prepared via non-hydrolytic sol-gel method with tetrabutyl titanate as precursor and ethanol as oxygen donor.TiO2 dense layer was prepared on FTO conductive glass through dipping method.The photo-electric conversion efficiency of the DSSC with TiO2 dense layer was 8.24%.(2)Anatase TiO2 nanotubes power was fabricated with TiO2 nanoparticles power via hot alkali treatment method.The length of nanotube,the wall thickness and the inner diameters were about 100 nm,2 nm and between 6nm-8nm,respectively.The short-circuit photocurrent,open-circuit voltage,fill factor and photo-electric conversion efficiency of the DSSC with TiO2 nanotubes photoanode were 13.61mA·cm-2,0.71V,0.71 and 6.95%,respectively.(3)The nanotubes film was prepared via template method with ZnO nanorods film as template.The nanotubes were about 150nm in external diameter and about 40nm in wall thickness.The short-circuit photocurrent,open-circuit voltage,fill factor and photo-electric conversion efficiency of the DSSC with TiO2 nanotube photoanode were 4.63 mA·cm-2,0.74V,0.62 and 2.15%,respectively.(4)ZnO nanospheres were prepared through alcohothermal method with zinc acetate as zinc source.TiO2 spheres were prepared by template method with ZnO nanospheres as templates.In the same experiment conditions,the TiO2 spheres photoanode and TiO2 nanoparticles photoanode were prepared and used in DSSC.The photoelectric conversion efficiency of TiO2 nanospheres DSSC was 31.31%lower than TiO2 nanoparticles DSSC.And its parameters were as follows:the photoelectric conversion efficiency,open circuit voltage,short circuit current and fill factor were 5.66%,0.81 V,10.18 mA·cm-2 and 0.69,respectively.