Synthesis And Properties Of New Quinoxaline-based Functional Polymer/Oligomer Solar Cells

Solar energy is an unlimited supply of green energy. Nowadays global naturalresources are out of shortage, and the environment pollution is increasingly serious, sothe international community advocates using low carbon energy to protectenvironment. In view of this, the reasonable development and use of solar energy hasvital significance to relieve the energy crisis and promote the social development. Atpresent, the polymer solar cells and the DSSC have been studied all over the wordbecause of their unique advantages. Quinoxaline groups with conjugate ring are lackof electron, and are usually used to synthesize organic semiconductor materials. TheQuinoxaline group has very good thermo and chemical stabilities, the absorptionspectrum and electrochemical performance could be improved by structuremodification. Furthermore, it has very strong absorption in IR/near-IR region. In thispaper, new alkynes monomers with push-pull (D-A) structures have been designedand synthesized to effectively induce the absorption spectra red shift and reduce thepolymer band gap. Further to synthesis their relevant polymers via Sonogashirareaction, part of which contain the metal Pt in the main chain. At the same time, thetwo new small molecule dyes were synthesized. The structures of the intermediateproducts and the target products were conducted by NMR, FT-IR and MALDI-TOF.And the photochemical, electrochemical natures of the copolymers and dyes havebeen carried out by UV/vis spectra, PL spectra and cyclic voltammetry. The researchcontent as follows:1. Conjugate polymers (P1-P6) with quinoxaline or thiazolo[5,4-d]thiazolegroups and the metal Pt in the main chain were designed and synthesized through theSonogashira polymerization reaction. The thermal stability, photochemicalelectrochemical properties of the two kinds of polymers was studied systematically.The results showed that the introduction of the metal Pt to the main chain of thepolymer, have broadened the range of spectrum response obviously, which couldimprove the efficiency of the device effectively.2. Pure organic polymers (P7-P10) containing quinoxaline groups in thebackbone were designed and synthesized via Stille coupling polymerization reaction.The thermal stability, photochemical electrochemical properties of the four polymerswas also reaserched systematically. This design concept is closely related to the content of the first chapter. On the one hand, to broaden the species and theapplication scope of quinoxalin; on the other hand, the successful synthesis of thepolymer in this series could provides us material basis to study metal nuclear functionin the metal organic polymer, and contribute to the study of such polymerstructure-performance relationship systematically.3. Two organic dyes (D1, D2), containing N, N-dialkoxyphenyl aniline aselectronic donor and cyanoacetic acid as electronic acceptor, were designed andsynthesized using Stille reaction and Knoeveenagel reaction. Compared to thiophenegroup in D2, the quinoxaline group has better stability, can effectively broaden therange of spectral response. With the introduction of quinoxaline group, the photo andthermo stabilities of the dye were improved, thus conducive to improvement of thedevice performance.