Quadrupole Moment Induced Morphology Control Via a Highly Volatile Small Molecule in Efficient Organic Solar Cells

• Published in: Advanced functional materials 2021-05, Vol.31 (18), p.n/a
• Main Authors: Yu, Runnan, Yao, Huifeng, Xu, Ye, Li, Jiayao, Hong, Ling, Zhang, Tao, Cui, Yong, Peng, Zhongxiang, Gao, Mengyuan, Ye, Long, Tan, Zhan'ao, Hou, Jianhui
• Format: Article
• Language: English
• Subjects: Active control; Additives; Charge distribution; Control equipment; Materials science; Morphology; morphology control; organic solar cells; Photoelectric effect; Photoelectricity; Photovoltaic cells; Quadrupole interaction; quadrupole moment; Quadrupoles; Solar cells; solid additives; volatility
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202010535

Developing novel solid additives has been regarded as a promising strategy to achieve highly efficient organic solar cells with good stability and reproducibility. Herein, a small molecule, 2,2′‐(perfluoro‐1,4‐phenylene)dithiophene (DTBF), designed with high volatility and a strong quadrupole moment, is applied as a solid additive to implement active layer morphology control in organic solar cells. Systematic theory simulations have revealed the charge distribution of DTBF and its analog and their non‐covalent interaction with the active layer materials. Benefitting from the more vital charge–quadrupole interaction, the introduction, and volatilization of DTBF effectively induced more regular and condensed molecular packing in the active layer, leading to enhanced photoelectric properties. Thus, high efficiency of over 17% is obtained in the DTBF‐processed devices, which is higher than that of the control devices. Further application of DTBF in different active layer systems contributed to a deeper comprehension of this type of additive. This study highlights a facile approach to optimizing the active layer morphology by finely manipulating the quadrupole moment of volatile solid additives. Quadrupole moment induced morphology control in organic solar cells is realized by a highly volatile solid molecule (DTBF). The presence of a strong charge‐quadrupole interaction among the DTBF‐processed active layer can effectively alter the morphology and introduce beneficial optoelectronic properties. This work realizes a high efficiency of over 17% and provides a design guideline for efficient solid additives.