Regulating exciton bonding energy and bulk heterojunction morphology in organic solar cells <i>via</i> methyl-functionalized non-fullerene acceptors
作者:Wei Gao、Tao Liu、Zhenghui Luo、Lin Zhang、Ruijie Ming、Cheng Zhong、Wei Ma、He Yan、Chuluo Yang
DOI:10.1039/c9ta00597h
日期:——
important for non-fullerene small molecule acceptors (NF-SMAs) to tune their absorption, energy levels, and crystallization properties. Herein, we designed and synthesized three SMAs, namely, BTTIC-0M, BTTIC-2M, and BTTIC-4M by adding the methyl unit into 2-(6-oxo-5,6-dihydro-4H-cyclopenta[c]thiophen-4-ylidene)malononitrile (CPTCN). Methyl group, with its slight electron-donating ability, significantly elevates
缺电子端基(EGs)对于非富勒烯小分子受体(NF-SMA)调节其吸收,能级和结晶特性非常重要。在这里,我们通过将甲基单元添加到2-(6-oxo-5,6-dihydro-4 H -cyclopenta [ c ] thiophen)中,设计并合成了三种SMA,即BTTIC-0M,BTTIC-2M和BTTIC-4M。-4-亚丙基)丙二腈(CPTCN)。甲基,具有轻微的给电子能力,可显着提高LUMO能级,但不会严重影响基于CPTCN的SMA的带隙,从而有助于减少能量损失(E损失)。)。对供体-受体(DA)复合物的深入动态理论模拟表明,可以通过连续增加SMAs端基上的甲基来微调激子键能(BE)。甲基取代的EG降低了驱动力,还增强了电荷传输(CT)态激子的BE,导致激子解离效率降低。但是,我们发现一种甲基官能化的CPTCN使基于PBDB-T:BTTIC-2M的有机太阳能电池(OSC)的功率转换效率(PCE)高达13