Influence Of Aspect Ratio And Dipole Moment Of The Dye Molecular On The Properties Of Dye Sensitized Solar Cells

Dye-sensitized solar cells?DSSCs?,which is a new type of photoelectric chemical solar cell with simple preparation procedure,low cost,friendly environment action and high photoelectric conversion efficiency,is considered to be one of the best alternatives to silicon solar cells.In this paper we research the preparation technology of liquid and solid state dye sensitized solar cells.Triphenylamine and indoline dyes is applied to the solar cells as sensitizer and discussed the effect of aspect ratio and dipole moment on the device performance.The TiO₂ photoanode film is prepared by doctor blade.The impact of sintering curve,coating thickness and light scattering layer are discussed.The results show when the composition of the TiO₂ film is 11 ?m20 nmTiO₂ + 4 ?m200 nm TiO₂ N719 as sensitizer,the photoelectric conversion efficiency is 6.05%.The TiO₂ paste and ethanol is mixed according to different proportions and spin-coated on the treated conductive glass.Conversion efficiency of solid state dye sensitized solar cell with different thickness is compared.The optimum thickness is 1?m with conversion efficiency of 1.42%.Two groups of dye: MTPA-Pyc,MTPAcc,MTPAc and MIND-Pyc,MINDcc,MINDc,that have different aspect ratios were studied for their performances as sensitizer in dye sensitized solar cells?DSSCs?.The effects of solvent,the amount of dye molecules adsorbed on the surface of TiO₂ and dye aggregation were investigated.Results show that MTPAcc has the most suitable aspect ratio among three dyes with the highest and best photovoltaic properties.Polariry of absorption solvents can influent not only the absorbed amount of dyes at TiO₂ but also the dye aggregation.MTPA-Pyc with a large aspect ratio exists in H-aggregation in tolene and tetrahydrofuran,whereas J-aggregation in acetonitrile.MTPAcc was found with high absorption amount at TiO₂ but without aggregation,resulting in the best photovoltaic properties of corresponding DSSC with a photon-to-electricity conversion efficiency of 5.72%.Therefore,the aspect ratio of dye sensitizers is significant to the photovoltaic properties of DSSC.MINDcc has the best photoelectric performance among the three dyes,supporting the above conclusion again.The same method was used to study the impact of dipole moment on the efficiency of the device?MIND-Pyc,MTPA-Pyc and MoTPA-Pyc?.The results show that in the polar solvents acetonitrile,MoTPA-Pyc with the largest dipole moment has the best photoelectric performance.But in a non-polar solvent toluene,MIND-Pyc is the best.According to molecular polarity,selecting the appropriate polar solvents will help to improve the efficiency of dye-sensitized solar cell.