两种不对称苝酰亚胺小分子的合成及光伏应用研究

Synthesis and Photovoltaic Application Research of Two Asymmetric Perylene Diimide Small Molecules

摘要:

以3,4,9,10-苝四酸二酐为原料，通过在分子两端芳香环（bay位）分别连接2-甲氧基乙氧基和硝基，合成了两个不对称苝酰亚胺小分子N, N’-二(2-乙基己基)-1-(2-甲氧基乙氧基)-7-硝基-3,4,9,10-苝四羧酸二酰亚胺(Ⅲ)和N, N’-二(2-乙基己基)-1-(2-甲氧基乙氧基)-6,7-二硝基-3,4,9,10-苝四羧酸二酰亚胺(Ⅳ)，利用1H NMR, 13C NMR和MS对其结构进行了表征。通过密度泛函理论计算优化了分子空间立体构象、扭曲结构和电子云分布；紫外-可见吸收光谱(UV-Vis)结果表明，与无取代基的苝酰亚胺相比，Ⅲ和Ⅳ的最大吸收峰红移至559 nm和572 nm。半峰宽变宽为104 nm和112 nm；经循环伏安(CV)测试估算分子Ⅲ和Ⅳ的HOMO、LUMO能级分别为−5.85 eV、−3.55 eV和−5.87 eV、−3.62 eV；在相对湿度为50%的在大气环境中，构建了有机太阳能电池器件，Ⅲ和Ⅳ分别与苯并二噻吩联噻吩并噻吩类聚合物（PTB7-Th）共混时器件性能分别提高到短路电流密度JSC= 3.6 mA/cm2，开路电压VOC=0.30V，填充因子FF= 0.40，光电转换效率PCE= 0.42%和JSC= 4.00 mA/cm2，VOC= 0.25 V，FF= 0.41，PCE= 0.40%。

Abstract:

Two asymmetric perylene diimide small molecules were synthesized, namely N, N’-di(2-ethylhexyl)-1- (2-methoxyethoxy)-7- nitryl - perylene -3, 4, 9, 10-tertracarboxylic acid diimide (Ⅲ) and N, N’-di(2-ethylhexyl)-1- (2-methoxyethoxy)- 6, 7- dinitryl - perylene-3, 4, 9, 10-tertracarboxylic acid diimide (Ⅳ). It was synthesized from 3, 4, 9, 10-perylenetetracarboxylic dianhydride by via connect 2-methoxyethoxy and nitryl to the opposite sides of the molecular bay-positions. The structures were characterized by 1H NMR, 13C NMR and MS. We have used density functional theory to optimize the calculation of molecular spatial stereoscopic conformation, the molecular twisted backbone and distribution of electron cloud was also studied; Ultraviolet-Visible absorption spectra (UV-Vis) showed that there is obvious red-shift on the maximum absorption peak, and the peak width at half height broaden; Through the cyclic voltammetry (CV), we calculated that the HOMO and LUMO energies of molecule Ⅲ are −5.85 eV and −3.55 eV, the molecule Ⅳ are −5.87 eV and −3.62 eV. Finally, at a relative humidity of 50% in atmospheric environment, the device of organic solar cell was constructed that Ⅲ and Ⅳ were respectively blended with polymer of benzodithiophene-alt-polythiophene (PTB7-Th). The performance of the device that the JSC= 3.6 mA/cm2, VOC=0.30V, FF= 0.40, PCE= 0.42% and JSC= 4.00 mA/cm2, VOC= 0.25 V, FF= 0.41, PCE= 0.40%.