High performance alternating polymers based on two-dimensional conjugated benzo[1,2-b:4,5-b′]dithiophene and fluorinated dithienylbenzothiadiazole for solar cells
作者:Zhiyuan Cong、Shuo Liu、Baofeng Zhao、Weiping Wang、Hongli Liu、Jin Su、Zhaoqi Guo、Wei Wei、Chao Gao、Zhongwei An
DOI:10.1039/c6ra13595a
日期:——
properties, a high open-circuit voltage (Voc) of 0.85 V was obtained for the optimal conventional polymer solar cells (PSCs) based on a two-fluorine-substituted analogue P3 blended with [6,6]-phenyl-C71 butyric acid methyl ester (PC71BM) as the active layer (1 : 1.5), giving rise to a high power conversion efficiency (PCE) of 7.48%. The influences of the molecular weight (MW) of P3 on the device performances
基于二维共轭烷基噻吩基取代的苯并[1,2- b:4,5- b ']二噻吩(BDTT)和氟化4,7-二烷基噻吩基-2,1,3-苯并噻二唑(DTBT)的三种供体-受体聚合物合成了这些衍生物并将其用作体异质结太阳能电池的施主材料。研究了氟取代对聚合物的吸收性能,能级,介电常数和光伏性能的影响。我们发现,在DTBT单元上引入氟原子可以有效地加深最高占据分子轨道(HOMO)的能级并增加聚合物的介电常数。由于这些改进的特性,开路电压(V oc)的最佳常规聚合物太阳能电池(PSC)的0.85 V)是基于将两个氟取代的类似物P3与[6,6]-苯基-C71丁酸甲酯(PC 71 BM)混合作为活性层(1:1.5),可实现7.48%的高功率转换效率(PCE)。进一步研究了P3的分子量(MW)对器件性能的影响,并提高了中等分子量P3基器件的光伏参数,相应的开路电压(V oc)为0.80 V,发生短路14.7 mA