Synthesis And Design Of D-D-?-A Arylamine Organic Photosensitizer And Their Photovoltaic Performance

Since the industrial revolution,the fossil fuels which consumed most of the globle energy has changed people's lifestyle and promoted the development of human civilazition.However,the fossil fuel age has also created two significant issues for the world to deal with: climate change mitigation and the security of energy supply.Dye sensitized solar cells(DSSCs),a hybrid organic-inorganic system,have received great attention due to their low manufacturin cost,excellent photovoltaic performance and high versatility in the last decade.Arylamine organic dyes with donor(D),?-bridge(?)and acceptor(A)moieties for dye-sensitized solar cells(DSCs)are considered one of the most promising photovoltaic devices.The D–A–?–A strategy to organic dyes has been developed and well-studied,by contrast,reports on exploration of new electron-donating donors for D–D–?–A organic dyes are very limited.There is much room left for further development of D–D–?–A organic dyes by incorporating of different terminal electron donor.Moreover,some electron donors such as carbazole,phenothiazine and dithieno[3,2-b:2?,3?-d]pyrrole(DTP)can also be incorporated in two different directions at the end of the organic dyes.Nevertheless,to the best of knowledge,reports on influence of the donor direction(carbazole/phenothiazine)on the performance of the D–D–?–A dyes are lacking.With this in mind,in this work,four new D–D–?–A organic dyes with bis(amine)donor or dithieno [3,2-b:2?,3?-d]pyrrole(DTP)have been designed and synthesized for a investigation of the influence of the terminal electron donor in D–D–?–A organic dye-sensitized solar cells,which are synthesised according to using indanone,bithiophene and fluorine etc.as the starting material by Suzuki,Vilsmeier Haack,Buchwald-Hartwig and Knoevenagel reaction.In addition,we investigated the photophysical,electrochemical properties and their photovoltaic performance of the D–D–?–A DSSCs based on the four dyes employing cobalt-phen and cobalt-bpy electrolytes.The main conclusions are as follows:(1)In spite of the slightly blue shift of maximum absorption wavelength in comparison with the M43/44,the M45 dye exhibits a stronger and broader absorption.(2)The introduction of different terminal donors has a great impact on the energy level of the dyes,thus affecting the regeneration efficiency of the dyes and photovoltaic performance of the cells.(3)DSCs based on M45 with the Co-phen electrolyte exhibit good light-to-electric energy conversion efficiencies as high as 9.02%.