Central dicyanomethylene-substituted unsymmetrical squaraines and their application in organic solar cells
Central dicyanomethylene-substituted unsymmetrical squaraines and their application in organic solar cells
复制标题
中心二氰亚甲基取代的不对称方酸菁及其在有机太阳能电池中的应用
DOI：
10.1039/c8ta00750k
复制
发表时间：
2018
影响因子：
11.9
通讯作者：
Yan Huang
中科院分区：
文献类型：
--
作者：
Jianglin Wu;Daobin Yan;Qinfen Wang;Lin Yang;Hisahiro Sasabe;Takeshi Sano;Junji Kido;Zhiyun Lu;Yan Huang
通过在中心方受体核上进行双氰亚甲基化反应，合成了三种不对称方酸菁（USQ），即diCN-USQ-1-3，并与相应的参比化合物（USQ-1-3）进行了深入的比较研究。结果表明，在中心方环上引入二氰基亚甲基后，荧光团的整个π共轭体系的性质发生了明显的变化，如光学带隙降低，HOMO能级加深，偶极矩增大，偶极矩方向发生变化等.因此，溶液处理的本体异质结小分子有机太阳能电池使用这些diCN-USQ作为电子供体材料的BHJ-SMOSC（BHJ-SMOSC）可以同时显示出大大增强的开路电压和显著增加的短路电流密度，并且因此比它们相应的基于USQ的参考器件显著更高的功率转换效率（PCE（PCE：diCN-USQ-1-3依次为1.46%、1.91%和4.58%，USQ-1-3依次为0.45%、0.77%和3.05%）。注意，基于diCN-USQ-3的器件显示出4.58%的PCE，这是所有报道的基于中心取代的方酸菁的有机太阳能电池中的最高值。
By dicyanomethylenation on the central squaric acceptor core, three unsymmetrical squaraines (USQ), namely diCN-USQ-1–3, were synthesized, and in-depth comparative studies between them and their reference compounds (USQ-1–3) were carried out. The results indicate that the presence of dicyanomethylene groups on the central squaric ring will lead to distinctly altered properties on the entire π-conjugated system of the fluorophore, such as lowering of the optical bandgap, deepening of the HOMO energy level, increasing of the dipole moment and changing on the dipole moment direction. Consequently, solution-processed bulk-heterojunction small molecule organic solar cells (BHJ-SMOSCs) using these diCN-USQs as electron donor materials could simultaneously show much enhanced open-circuit voltage and significantly increased short-circuit current density, and hence drastically higher power conversion efficiencies (PCEs) than their corresponding USQ-based reference devices (PCE: 1.46%, 1.91%, and 4.58% for diCN-USQ-1–3, and 0.45%, 0.77%, and 3.05% for USQ-1–3 in sequence). Note that the diCN-USQ-3-based device shows a PCE of 4.58%, which is the highest value among all the reported organic solar cells based on centrally substituted squaraines.