Synthesis And Photovoltaic Properties Of D-A Conjugated Polymers Containing Rhodanine And Thienoisoindigo

Compared to inorganic solar cells, the organic polymer solar cell have got more and more attention because they are low cost, function and structure easy to adjust and can make large-area flexible devices.The design, synthesis and optimize of optoelectronic properties of polymer donor materials are the main focuses in this field. This dissertation is focusing on the design and synthesis of new organic polymer donor materials, synthesis seires of main chain-side chain D-A polymers with ethylrhodanine and main chai D-A polymers based on thienoisoindigo(ThID), the optical, electrochemical, and photovoltaic properties of these D-A copolymers were investigated in detail. The main results are as follows:1. Four main chain-side chain D-A polymers, PHDBDT-T-R, PEHBDT-T-R, PHDBDT-T-TR and PEHBDT-T-TR containing the same backbone of BDT-T but different side chains bearing on BDT and T were designed and synthesized to investigate effects of the side chains of BDT and the inserted thienylvinyl between thiophene and 3-ethylrhodanine units on absorption spectra, energy levels, film morphology and photovoltaic performance solubility. Results showed that the more branched side chains could increase the molecular solubility but bring large space steric hindrance,reduce the miscibility of the polymer with PC70 BM. The introduction of thienylvinyl moiety between thiophene and 3-ethylrhodanine benefits to broaden the absorption and lower the bandgaps. PCE of PSCs based on the copolymers is 1.01%, 4.04%, 3.47%, and 4.25%, respectively.2. A series of novel D-A copolymers PBDT-T-S-ThID、PC-ThID and PF-ThID based on thienoisoindigo unit have been designed and synthesized. We systematically studied the effects of electron donor benzo[1,2-b:4,5-b]dithiophene, carbazole and fluorene on the photophysical, electrochemical properties and photovoltaic performance. The results showed that thienoisoindigo unit has a strong electron-withdrawing ability, with different donor cell copolymerization copolymers has very wide absorption, but energy levels isn’t match with PC70 BM energy level well,which is disadvantage to the transfer of electric charge, so based on the series of copolymers of photoelectric conversion efficiency only up to 1.16%。...