萘酰亚胺-卟啉星型电子受体分子的构筑及其在非富勒烯太阳能电池中的应用

Star-Shaped Electron Acceptor based on Naphthalenediimide-Porphyrin for Non-Fullerene Organic Solar Cells

非富勒烯太阳能电池目前已经成为有机太阳能电池的研究热点,大量的共轭电子受体分子被开发,并成功应用到高性能光伏器件中。共轭分子作为非富勒烯电子受体,需要综合考虑吸收、能级、电子传输以及结晶性等,其中宽吸收光谱可以提高对太阳光谱的利用,是分子设计中重要因素之一。本工作中,我们设计一种新型电子受体分子,以卟啉为核、萘酰亚胺为端基以及炔为桥连基团。这种新型分子具有近红外的吸收光谱以及合适的能级。将一种具有吸收互补的共轭聚合物为电子给体,星型分子为电子受体应用到电池的活性层中,我们获得了1.8%的能量转换效率,电池的光谱响应为300–900 nm。实验结果证明了这种以卟啉为核的分子设计在实现近红外吸收的电子受体方面具有重要应用前景。

Non-fullerene organic solar cells are of broad and current interest in the field of organic solar cells, and show promising application in high performance solar cells. When designing conjugated molecules as non-fullerene materials, several parameters, such as absorption, energy levels, charge transport, and crystallinity should be considered. Among them, absorption spectra are an important parameter that determine the efficiency of sun-light harvesting. In this work, we explore a new near-infrared electron acceptor naphthalenediimide-porphyrin （NDI-Por） by using electron-donating porphyrin as the core, and four NDI as end groups with ethynyl as linkers attached to the meso-position of porphyrin. This star-shaped molecule exhibits absorption spectra up to 900 nm. NDI-Por was incorporated into non-fullerene solar cells as an electron acceptor, and together with a wide-band gap polymer donor, an initial power conversion efficiency of 1.80% could be achieved. In particular, the solar cells exhibit a broad photo-response from 300 to 900 nm. Our results demonstrate that it is an efficient strategy to incorporate porphyrin into conjugated molecules to realize non-fullerene materials with near-infrared absorption spectra.