Synthesis And Properties Of Polymer Solar Cells Materials

With the continuous development of economy, energy problems have become major issues of great concern to all of countries in the world. The use of solar energy has also become the focus research of the national scientists. The organic polymer solar cells with the benefit of light, thin and soft have received extensive attention. In this thesis, a series of novel donor-acceptor conjugated polymer photovoltaic materials were designed and synthesized. All of the polymers were characterized by1H NMR and13C NMR. The molecular weight of polymers was measured by gel permeation chromatography (GPC). Thermal stability, optical property and electrochemical performance of polymers were also studied.Thiophene, benzene and so on are well-known functional groups. Because of the information, a series of benzothiadiazole (BT) derivatives with conjugated side chains of thiophene vinyl, benzene vinyl and so on units were designed and synthesized. Subsequently, copolymers PBDDTS1, PBDDTS2, PBDDTS3, PBDDTP1, PBDDTP2, PBDDTP3, PBDDTC1, PBDDTC2and PBDDTC3based on benzothiadiazole derivatives and dithienosilole (DTS), dithienopyrrole (DTP), cyclopentadithiophene (DTC) derivatives were synthesized via Stille coupling reaction. Thermal stability of them are very well and their thermal decomposition temperatures of losing5%weight have reached about350℃. These polymers have two absorption peaks in the ultraviolet region and visible region, meanwhile the maximum absorption peaks of polymers solid films are located at613nm,613nm,604nm,650nm,653nm,645nm,616nm,620nm and609nm, respectively. They show broad absorption band, and the absorption spectra of the nine polymers are covered with visible region. From the results of electrochemical cyclic voltammetry, these nine polymers have low bandgaps under1.6eV and almost agreed with optical bandgap.BODIPY derivatives synthesized six novel D-A copolymers PBTDTS1, PBTDTP1, PBTDTC1, PBTDTS2, PBTDTP2and PBTDTC3with dithienosilole, dithienopyrrole, cyclopentadithiophene derivatives via Stille coupling reaction. Thermal stability of them are well and their thermal decomposition temperatures of losing5%weight have reached about350℃. These polymers have three absorption peaks in the ultraviolet region and visible region, and the maximum absorption peaks of polymers solid films are located at580nm,605nm,585nm,598nm,622nm and 606nm, respectively. They show broad absorption band, and the absorption spectra of these six polymers are covered with visible region. These polymers have low bandgap under1.70eV and almost agreed well with optical bandgap.A series of the copolymers PBTBTT1, PBTBTT2, PBTZBTT, PBODBTT and PBTDBTT based on benzothiadiazole derivatives, BODIPY derivatives and so on as electron acceptor and benzotrithiophene derivatives as electron donor were synthesized via Stille coupling reaction. These polymers show very well thermal stability. From UV-Vis absorption spectroscopy, we find the maximum absorption peaks of solid films are located at585nm,596nm,620nm,626nm and639nm, respectively. The absorption band of them are broad, and the absorption spectra of these five polymers are covered with visible region. From the results of electrochemical cyclic voltammetry, these polymers have low bandgap which are of the low bandgap polymer solar cells and almost agreed well with optical bandgap, too.