Synthesis Of Organic Dyes Based On Fused Dithienopyrrole And Their Photovoltaic Performance

The issuses of energy and environmental have became more prominent in today’s society.with the development of the society, people urgently hope to find a kind of green energyresources. Dye-sensitized solar cells due to simple production process and low cost hasgradually got good reputation.In this thesis, considering the structure of dye C214which has been synthesized by ourgroup, I designed and syntheticed another two kind of sensitizing dyes X62-63which arebased on dihexyloxybenzene-substituted triphenylamine as electron dornnr, Nitrogen Pyrrolethiophene and dithienopyrrole as conjugate bridges. triphenylamine as the starting material fordye (X62-63), through N-bromosuccinimide (NBS) bromide, Suzuki coupling reaction, Stillecoupling reaction, Vilsmeier reaction, Knoevenagel condensation reaction, The two neworganic sensitizers was compared and contrasted to C214in the tris(1,10-phenanthroline)cob-alt(II/III) or the iodide/triiodide redox couple. We analysis the structure-performancerelationship of photosensitizers.Photophysical/electrochemical properties of X62-63in solution and on TiO2film wereinvestigated. The dyes display unenterrupted strong absorption between450-550nm, Themolar extinction coefficients of C214is31×103, X62is56×103, X63has reached at75×103M–1cm–1. It shows they have good light-harvesting efficient properties. The HOMOand LUMO of these three dyes match with titanium dioxide energy level and electrolyteenergy level, it is good to be as a sensitizer.Interestingly, with the same electrolyte, C214containing DHO-TPA electron donorconfers an improved electron lifetime in comparison with its DHOB-TPA analogue, X62. Thisobservation has aroused us to conclude that the bulky electron donor is not alwaysadvantageous to long electron lifetime. On the other hand, the photocurrent performance ofthin-film DSCs was found to be governed by the molar absorption coefficients of dye. Inconjunction with the Co(II/III)tris (1,10-phenanthroline) based redox electrolyte, X63sensitized DSCs affords a short circuit photocurrent of11.5mA cm-2, an open circuit voltageof948mV, and a fill factor of0.69, corresponding to an overall conversion efficiency of7.52%under standard AM1.5sunlight.The paper also designed four kind of Nitrogen pyrrole bithiophene sensitizing dyesX66-69, which have not untraditional D-π-A structure. Pyrrole nitrogen bithiophene are oftenused as part of a conjugated bridge, because it has a new conjugated structure. so we decide toinvestigate whether also has a good capacity for the electron. thiophene is a starting materialfor dye X66-69, through the N-bromosuccinimide (NBS) bromide, Friedel-Crafts acylation,Suzuki coupling reaction and so on. we completed four synthetic dyes, but there is no time forme to test those performance of that, we fall to summarize experimental results.