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

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.

Automated summary

The use of the small molecule additive DTBF, with high volatility and a strong quadrupole moment, to control the active layer morphology in organic solar cells has led to enhanced photoelectric properties and efficiencies reaching over 17%. This study highlights a simple approach to optimizing active layer morphology by manipulating the quadrupole moment of volatile solid additives.