The Research Of The Conjugated Bipyridine Ruthenium Sensitizers And The Application In Dye-sensitized Solar Cells

Ruthenium sensitizer is the first study, the most widely used and most mature one indye-sensitized solar cells. Currently, the amphiphilic Ruthenium sensitizers, such asCYC-B11with the overall conversion efficiency of11.5%, and initially put into production.We discussed the fluence on two series bipyridyl ruthenium sensitizers of the electrondonating groups with different levels of conjugation (alkyl, alkoxy, alkylthio, amino, alkylthiophene, thiophene alkoxy, alkylthio thiophene) and the electron withdrawingsubstituents groups (carboxyl group, carboxyl double, double double carboxy, cyanodouble carboxy), may design sensitizers with a better efficiency than the existing N3.Furthermore theoretical and experimental mutual authentication: a group according to thesynthesis of a modified fixed-COOH,-CH=CH-COOH,-CH=C-(COOH)2and-CH=C-(COOH)(CN) four series sensitized agent.As part of the work of this thesis project funded by the National Natural ScienceFoundation of China (No.2011AA050510), and obtained some interesting results in thefollowing two areas of research:1A theoretical study on Ruthenium sensitizer agents1) series oneTwenty novel amphiphilic sensitizers were designed and studied using the densityfunctional theory and time-dependent density functional theory calculations. They aredivided into five groups according to the characteristics of the structure. The influence of–COOH,-CN and-C=C-between pyridine and-COOH were discussed, through theenergy levels, electronic absorption spectra and electron orbital space distribution analysis.Group three is the efficient one, which these molecules may be the most promisingsensitizers in ruthenium complex sensitized solar cells.2) series twoFifteen novel amphiphilic sensitizers (Divided into five groups) were designed andstudied using the density functional theory and time-dependent density functional theorycalculations. The influence of–COOH,-CN and-C=C-between pyridine and-COOHwere discussed, through the energy levels, electronic absorption spectra and electron orbital spatial distribution analysis. Group three is the efficient one, that these moleculesmaybe be the most promising sensitizers in ruthenium complex sensitized solar cells2Experimental Study-modified four series of fixed groups1) containing-COOHA amphiphilic Ruthenium sensitizer L125with4,4’-dimethyl-2,2’-bipyridineintroduced was synthetized. Through a combination of theoretical and experimentalapproach, we could get a better understanding of these molecules. We found L125is notideal ruthenium sensitizer and4,4’-dimethyl-2,2’-bipyridine may not preferably rutheniumsensitizer ligand when compared with N3.2) containing-CH=CH-COOHTwo novel ruthenium complexes, L131and L132, we expand the conjugation chain length with the4,4’-bis(cis-carboxyvinyl)-2,2’-bipyridine. L131and L132As shown from the optical data, donor groups(methyl and nonyl) have a great influence on the performance of the dye molecules. Through acombination of theoretical and experimental approach, we could get a better understanding of thesemolecules. The photovoltaic data of L131-sensitized and L132-sensitized solar cells have achievedhigher Jsc and η values compared to those for N3and K8-sensitized solar cells, with7.73%and7.85%overall power conversion efficiency for LR131and L132measured in the air mass1.5global conditions,respectively.3) containing-CH=C-(COOH)2A novel ligand and relevant complexes, L121, L24and L133, in which theconjugation length of the anchoring ligands were extended with the4,4’-bis(2,2’-dicarboxylic acid-1-ethenyl)-2,2’-bipyridine. The photovoltaic data of L133shows a better battery performance than those of N3, which contributed to the longerconjugation length of the anchoring ligands were extended with the4,4’-bis(2,2’-dicarboxylic acid-1-ethenyl)-2,2’-bipyridine and the electron donor group,nonyl. L133battery respectively obtained sensitizer photoelectric conversion efficiency of6.84%.4) containing-C=C-(COOH)(CN)A new ligands and two new ruthenium complexes, L122and L123, 4,4’-bis(2-cyano-1-acrylic)-2,2’-bipyridine extended conjugated chains to expandconjugated chain length groups. The optical datas of L122and L123were significantlylower than those of N3. As seen from the HOMO-LUMO chart, from the perspective ofTiO2match, new ligands are not ideal.