Design And Synthesis Of Aromatic Compounds Containing Carbonyl Derivatives And Research Of Their Optoelectronic Properties

Aromatic compounds containing carbonyl derivatives have a very wide range of applications for their good electrical conductivity and decent response to light absorptions. However, the application in dye-sensitized solar cell is still lack of reports. Based on this type of structures, we designed and synthesized a series of novel conjugated molecules with push-pull electronic structures by introducing carbonyl derivative functional groups, which effectively regulate the functions and features of the molecules. Their optical properties were systematically studied, and the effects of such electron-withdrawing groups to the conjugated structure and intramolecular charge interactions were also discussed. Then they were used as sensitizers in dye-sensitized solar cells. The main contents are as follows:1. We designed and synthesized new dyes using bithiophene-3,3’-carboxylic acid anhydride as both acceptor and bonding groups, and triphenylamine donor groups were introduced into both ends of the compound making it a double-donor structure. The electronic push-pull effect of the molecule can be effectively adjusted by changing the thiophene number between the donor and acceptor. After the introduction of the two thiophene units, the absorption on the titanium dioxide film had a 30nm red-shift, and the extinction coefficient was greatly improved at the same time. To study the cell performance of such dyes, we optimized the battery condition by adjusting the concentration of the additive, and the anhydrides of the open ring protons dye treatment. Finally in the quasi-solid state solar cell, we reached a better efficiency.2. We designed and synthesized push-pull structure compounds with pyromellitic diimides as spacer. By substituting alkyl chain on the nitrogen atom of the imide group, we effectively improve the solubility of the molecules. By varying the length of the terminal alkoxy group, molecules can be regulated. DFT calculations show that the pyromellitic diimides have steric effect with the adjacent conjugation ring, so that cause great distortions in molecular skeleton, which suppressed the electron passing from one terminal of donor to the other acceptor. When applied to DSSC, electrons of the excited dyes can hardly inject into the electrode so that affect the battery performance.3. We designed and synthesized dye with benzodiazepine pyrrolidone as spacer. By Introducing triphenylamine as donor and cyanoacetate as acceptor, we form a zigzag shape of D-A-A dye. The absorption spectra of dye molecules cover the entire visible region, and reached 531nm in chloroform solution, which indicates a good photo-response property. By introducing the alkyl chain on the amide nitrogen atom, we effectively improve the solubility of the dye molecule and suppress the interaction between molecules. Therefore, we initially explored its application in dye-sensitized solar cells...