Theoretical Simulation, Synthesis And Photoelectric Properties Of Organic Small Molecule Dye Sensitizers Based On DPP And

Traditional non-renewable fossil fuels is bound to draw attention to new energy exploration and development, as a new, cheap and environmental protection, dye sensitized solar cells(DSSC) is becoming a hot spot of research in recent years. How to obtain high photoelectric conversion efficiency, not only relate to the DSSC production conditions and process, but also closely linked with the type of sensitizers.This paper reviews the research progress of phthalocyanine sensitizer, designed three kinds of different dye sensitizers, through theoretical calculation, verify its feasibility as a sensitizer, and further synthesis and simple characterization. This paper is supported by the National Basic Research Program of China(Grant No. 2011CBA00701) and National Nature Science Foundation of China(Grant No.21171084). Some valuing and significant results were obtained in the following subjects.The first chapter briefly describes the history of solar power, DSSC structure and the working principle. The current situation of the sensitizer in recent years are briefly summarized and several structures of efficient sensitizer are listed, especially for DPP sensitizer.In chapter 2, six senseitizers containing diketopyrrolopyrrole was designed and synthesized, named Pa DPP-1- Pa DPP-3 and Pt DPP-1- Pt DPP-3. The molecular orbital energy level and the special distribution of the molecular orbital were calculated by Density functional theory(DFT) with LANL2 DZ. Discussed the influence of DPP sensitizers contain different donor and acceptor. The theoretical calculation found that Pa DPP has a higher HOMO-LUMO gap compared to Pt DPP. And further measured UV-Vis absorbtion spectrum and fluorescence spectrum in chloroform, with rhodanine-N-acetic acid as the sensitized adsorption group agent than with cyanoacrylate absorb more redshift, the largest visible Pa DPP sensitizer absorbed more than 600 nm. The DPP Which Use Rhodanine-N-acetic acid as adsorption group have poor solubility, and not easily adsorbed on Ti O2. After testing found that the photoelectric conversion efficiency of the six kinds of sensitizers are very low, not even reached 1%, this may be related to the solubility of sensitizer too bad and the productionof device not mature enough.Five new DPP sensitizer were designed and synthesized with phenothiazine as dornor in the third chapter. Through the fine-tuning of the molecular structure, change the other end of the conjugated group(thiophene and benzene) and adsorption group of DPP, study the relationship between structure and properties. In order to increase the solubility of the sensitizer, each molecule with four alkyl chains. After the theoretical calculation found that the series sensitizer has higher energy gap than the Pt DPP1-3. The UV-Vis absorption spectra show that, rhodanine-N-acetic acid makes the maximum absorption peak of the sensitizer more redshift. Although these five kinds of sensitizer showed good light absorption, the photoelectric data is still not high.In the fourth chapter, three different sensitizers which contain tetrazine group were synthesized, It is also the first time to introduce Tetrazine to sensitizers. Identified the feasibility of the three kinds of sensitizing agent in DSSC by theoretical calculations, we have not yet studied the photoelectric properties as the limited time.The fifth chapter reviews the research progress of phthalocyanine sensitizer. The research of phthalocyanine compounds was gradually developed in recent two decades because of its low cost and high stability. The most representative is TT sets and PCS sets which synthesized by professor Gr?tzel et. The photo-to-electric conversion efficiencies of phthalocyanine sensitizers which contain phenoxy group and its derivatives have reached 6.4%. However, the common problem of the phthalocyanine sensitizers is the poor solubility. It is thus an important direction for the future research to design novel phthalocyanine sensitizers with higher solubility. This paper simply introduced the structure and the operation mechanism of DSSC as well as the dyes used currently. The structures and the characteristics of the symmetric phthalocyanines, the axial phthalocyanines and the ‘ push-pull ’ phthalocyanines are introduced in detail. The influences of different substituents on the photo-to-electric conversion performances and the solubility of the phthalocyanine sensitizers were also discussed. It was found that 3-dimensional structures can improve not only the solubility of the phthalocyanine sensitizers, but also the photo-to-electric conversion performances. In addition, some additive reagents can also improve the photo-to-electric conversion performances of the phthalocyanine sensitizers with poor solubility.