Wang Hongda, Xiao Liangang, Yan Lei, Chen Song, Zhu Xunjin, Peng Xiaobin, Wang Xingzhu, Wong Wai-Kwok, Wong Wai-Yeung
Institute of Molecular Functional Materials , Department of Chemistry and Institute of Advanced Materials , Hong Kong Baptist University , Waterloo Road, Kowloon Tong , Hong Kong , P. R. China . Email:
HKBU Institute of Research and Continuing Education , Shenzhen Virtual University Park , Shenzhen , 518057 , P. R. China.
Chem Sci. 2016 Jul 1;7(7):4301-4307. doi: 10.1039/c5sc04783h. Epub 2016 Mar 15.
Porphyrin-based small molecules as donors have long been ignored in bulky heterojunction organic solar cells due to their unfavorable aggregation and the low charge mobility. With the aim of striking a delicate balance between molecular design, morphology, interfacial layer and device fabrication to maximize the power conversion efficiency (PCE) of organic solar cells, three comparable porphyrin-based small molecules with an acceptor-donor-acceptor configuration have been developed for use as donor materials in solution processed small molecule bulk heterojunction organic solar cells. In these molecules, electron-deficient 3-ethylrhodanine is introduced into the electron-rich porphyrin core through 5,15-bis(phenylethynyl) linkers. Structural engineering with 10,20-bis(2-hexylnonyl) aliphatic peripheral substituent on the porphyrin core, instead of the aromatic substituents such as 10,20-bis[3,5-di(dodecyloxyl)phenyl], and 10,20-bis(4-dodecyloxylphenyl), can simultaneously facilitate stronger intermolecular π-π stacking and higher charge transfer mobility in the film, leading to a maximum PCE of 7.70% in a conventional device. The inverted devices have also been demonstrated to have long-term ambient stability and a comparable PCE of 7.55%.
基于卟啉的小分子作为给体，由于其不利的聚集性和低电荷迁移率，在体相异质结有机太阳能电池中一直被忽视。为了在分子设计、形貌、界面层和器件制造之间达成微妙的平衡，以最大化有机太阳能电池的功率转换效率（PCE），已开发出三种具有给体-受体-给体构型的可比较的基于卟啉的小分子，用作溶液处理的小分子体相异质结有机太阳能电池的给体材料。在这些分子中，缺电子的3-乙基罗丹宁通过5,15-双（苯乙炔基）连接基引入到富电子的卟啉核中。在卟啉核上采用10,20-双（2-己基壬基）脂肪族外围取代基而非诸如10,20-双[3,5-二（十二烷氧基）苯基]和10,20-双（4-十二烷氧基苯基）等芳香族取代基进行结构工程，可同时促进薄膜中更强的分子间π-π堆积和更高的电荷转移迁移率，在传统器件中实现了7.70% 的最大PCE。倒置器件也已证明具有长期的环境稳定性，PCE为7.55%，与之相当。
