聚方酸太阳电池材料的合成与表征

SYNTHESIS AND CHARACTERIZATION OF POLYSQUARAINE FOR SOLAR CELLS MATERIALS

通过Yamamoto偶联反应,合成了主链含有1,2-取代方酸和1,3-取代方酸结构单元的新型共轭聚合物光伏材料PTST.其结构经过红外光谱和核磁共振表征得以确证.热分析、紫外-可见吸收光谱和电化学性质研究表明,所得新型共轭聚合物PTST具有良好的热稳定性;在270～700 nm光谱范围内有宽而强的吸收,基本覆盖了整个可见光区域;取代方酸结构单元的引入可使聚合物的最低未占有轨道(LUMO)和能隙(Eg)降低.当PTST仅为60%掺混时,即可使聚(3-己基噻吩)的荧光完全淬灭,说明P3HT与PTST之间存在明显的光电子转移.

A novel polymer PTST bearing substituted squaric acid units in the main chain is synthesized via Yamamoto coupling reaction in the presence of Ni（PPh3）2Cl2 as catalyst,and the chemical structure of PTST is confirmed by 1H-NMR,13C-NMR and FTIR.The polymer PTST is readily soluble in common organic solvents such as chloroform,tetrahydrofuran,methylene dichloride,chlorobenzene and 1,2-dichlorobenzene,thus uniform thin films can be prepared from these solutions.The result from TGA shows that the polymer has excellent thermostability.The UV-Vis absorption spectrum of the polymer in tetrahydrofuran shows broad and strong absorption bands in the range of 270~700 nm and low band gap,suggesting that the polymer has good coverage with the solar spectrum.The result of cyclic voltammetry indicates that the lowest unoccupied molecular orbital（LUMO,-3.77 eV） and band gap（Eg） of the polymer are decreased by incorporation of the 3-cyclobutene-1,2-dione segment,implying that the polymer is nearly similar to that of perylene diimide-based polymers（-3.9 eV）,indicating that the polymer PTST is a potential n-type polymer material for fabrication of polymer solar cells.When blend poly（3-hexylthiophene）（P3HT） with the polymer PTST,even under a low doping ratio of 20 wt%,P3HT would lead to the PL quenching of P3HT obviously,while higher doping ratio of 1∶1（W∶W） would lead to completely quenching of emission from P3HT,suggesting that there exists efficient photoinduced electron transfer from P3HT to the target macromolecule.All these photophysical and electrochemical properties indicate that the objective copolymer PTST is a potential polymer acceptor material.