Inverstigation On The Polymer Photovoltaic Materials And Organic Dyes And Spectral Dynamics Of Dye-sensitized Solar Cells

Nowadays,with the continuously rapid development of science,technology and economy,there are increasing number of energies for needs.However,the reserve of traditional fossil energy is limited,and has made the environmental problems prominent.Therefore,people continue to try and develop new and renewable energy.As a kind of new energy,solar energy with its safety,no pollution,abundant,and low costs has been widely concerned by people,including organic solar cell lightweight,low cost,easy to make the flexible components,which has been concerned by the researchers.Bulk heterojunction polymer solar cells(PSCs)have achieved the highest photoelectric conversion efficiency of 14.9%and dye-sensitized solar cells(DSSCs)have reached the highest photoelectric conversion efficiency of 14.3%so far,However,there is still a long way to go before the commercial application,so researchers need to keep trying and discovering new materials,which are easy-to-adjust,and efficient organic materials.This dissertation has designed and synthesized polymer battery materials and dye-sensitized battery materials.And the physical properties of the material thermal stability,optical,electrochemical performance,photovoltaic performance were studied systematically.In addition,from microcosmic angle,Ultrafast spectroscopy is implemented to study the Spectral dynamics of dye-sensitized solar cells,and further revealed the performance of dye-sensitized solar cells.The main contents of this paper are as follows.1.Binary conjugated polymer PB and ternary conjugated polymer PT based on Ullizine were designed and synthesized.The molecular weight and thermal stability of the polymer were respectively characterized by gel permeation chromatography and thermogravimetric analysis,and study the photophysical,electrochemical and photovoltaic properties of polymers.The results of polymer solar cell devices based on PB and PT as electron donor materials show that the binary copolymer PB has a higher open circuit voltage with its lower HOMO,while the side chain containing Ullazine structural motifs Terpolymer PT has a wider absorption spectrum and higher hole mobility,resulting in higher short-circuit current and energy conversion efficiency.2.Starting from the dye sensitizer XD2,although its photoelectric conversion efficiency reaches more than 6%,its absorption spectrum is narrow and its molar extinction coefficient is relatively low.By changing the benzene ring to introduce thiophene as π bridge to increase the dye conjugation,broaden the spectrum and increase the molar extinction coefficient.In order to obtain higher photoelectric conversion efficiency,organic dye XD3 was designed and synthesized with triphenylamine as dye donor,DPP as the first receptor,cyanoacetate as the second receptor,thiophene double as π bridged based on D-π-A1-π-A2 type,which was applied to the DSSCs,and its photophysical properties,electrochemical properties and photovoltaic properties were systematically studied,and found that XD3 has a higher Molar absorption coefficient and a broader spectrum.Besides,the efficiency can be stabilized under continuous light.Finally the photoelectric conversion efficiency of 4.49%was obtained.3.In order to further reveal the effect of the dye sensitizers XD2 and XD3 structures with its π-bridged structures,Femtosecond spectrum,and nanosecond spectrum are used to study the two spectra kinetics.Both of them exhibited significant Stokes shift both in THF solution and grafted on oxide films.The fluorescence quenching efficiency reached more than 90%,and the hole injection efficiency reached more than 90%.