Synthesis And Application Of Porphyrin Based D-A-?-A Dyes For Dye-sensitized Solar Cells

Dye-sensitized solar cells(DSSCs)are considered to be one of the most promising solar cells owing to their unique advantages of low materials cost,simple fabrication process,easy colour adjustment and high power conversion efficiency.Sensitizer,as one of the key components in the DSSCs,plays a critical function in light harvesting and electron injection.That is to say,the ability of sensitizer directly determines the quality of the DSSCs.Among many photosensitizers,metal-free organic dyes have currently attracted worldwide scientific research attentions due to their high molar extinction coefficients,ease of structure tuning and environmental friendliness.In this thesis,a series of novel porphyrin based D-A-?-A Dyes are designed and synthesized,which have been successfully applied in DSSCs.Novel diketopyrrolopyrrole(DPP)based small organic molecules are synthesized as hole transporting materials for perovskite solar cells.The structure-performance relationships of the dyes and soalr cells are systematically studied through investigating their photophysical,electrochemical and photovoltaic properties.The specific research works are mainly based on the following partsIn the second chapter,two novel zinc porphyrin dyes containing benzotriazole or 2H-[1,2,3]triazolo[4,5-c]pyridine as auxiliary acceptors,respectively,were synthesized for dye-sensitized solar cells.These two auxiliary acceptors were firstly applied into porphyrin based dyes.The photophysical and electrochemical properties of the dyes were investigated.These two dyes show the whole visible light absorption when they are adsorbed on the TiO2 film,which means that they are promising sensitizers for dye-sensitized solar cells.The absorption intensity of triazolopyridine containing dye is higher than that of the benzotriazole containing dye,resulting in a better light harvesting.Thus,the dye-sensitized solar cell based on the former dye achieved higher conversion efficiency of 6.65% than the cell based on the benzotriazole containing porphyrin(6.17%)with chenodeoxycholic acid as the coadsorbant.In the third chapter,three novel diketopyrrolopyrrole(DPP)based small organic molecules were synthesized as hole transporting materials for perovskite solar cells.The effect of different donors and ? bridges on the performance of perovskite solar cells(PSCs)was discussed.The efficiency of TPADPP-1,TPADPP-2,PTZDPP-2 was 5.10%,9.85% and 8.16% respectively.Compared to TPADPP-2,the voltage of PTZDPP-2 was higher.Because the electron-donating ability of phenothiazine based donor was larger than that of triphenylamine based donor,the HOMO level of PTZDPP-2 was lower than that of TPADPP-2.We can also find that thiophene based ? bridges show good performance than benzene based ? bridges.