Li Wanning, Yao Huifeng, Zhang Hao, Li Sunsun, Hou Jianhui
State Key Laboratory of Polymer, Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P.R. China.
University of Chinese Academy of Sciences, Beijing, 100049, P.R. China.
Chem Asian J. 2017 Sep 5;12(17):2160-2171. doi: 10.1002/asia.201700692. Epub 2017 Jul 17.
Over the past decades, fullerene derivatives have become the most successful electron acceptors in organic solar cells (OSCs) and have achieved great progress, with power conversion efficiencies (PCEs) of over 11 %. However, fullerenes have some drawbacks, such as weak absorption, limited energy-level tunability, and morphological instability. In addition, fullerene-based OSCs usually suffer from large energy losses of over 0.7 eV, which limits further improvements in the PCE. Recently, nonfullerene small molecules have emerged as promising electron acceptors in OSCs. Their highly tunable absorption spectra and molecular energy levels have enabled fine optimization of the resulting devices, and the highest PCE has surpassed 12 %. Furthermore, several studies have shown that OSCs based on small-molecule acceptors (SMA) have very efficient charge generation and transport efficiency at relatively low energy losses of below 0.6 eV, which suggests great potential for the further improvement of OSCs. In this focus review, we analyze the challenges and potential of SMA-based OSCs and discuss molecular design strategies for highly efficient SMAs.
在过去几十年中，富勒烯衍生物已成为有机太阳能电池（OSCs）中最成功的电子受体，并取得了巨大进展，功率转换效率（PCEs）超过11%。然而，富勒烯存在一些缺点，如吸收较弱、能级可调性有限以及形态不稳定性。此外，基于富勒烯的有机太阳能电池通常存在超过0.7 eV的较大能量损失，这限制了功率转换效率的进一步提高。最近，非富勒烯小分子已成为有机太阳能电池中很有前景的电子受体。它们高度可调的吸收光谱和分子能级使得所制备的器件能够得到精细优化，并且最高功率转换效率已超过12%。此外，多项研究表明，基于小分子受体（SMA）的有机太阳能电池在低于0.6 eV的相对低能量损失下具有非常高效的电荷产生和传输效率，这表明有机太阳能电池具有进一步改进的巨大潜力。在本聚焦综述中，我们分析了基于小分子受体的有机太阳能电池面临的挑战和潜力，并讨论了用于高效小分子受体的分子设计策略。
