Elucidating the key role of fluorine in improving the charge mobility of electron acceptors for non-fullerene organic solar cells by multiscale simulations

Abstract

F–π interactions play a key role in improving the electron mobility of fluorinated electron acceptors for non-fullerene OSCs.

Functionalizing triptycene to create 3D high-performance non-fullerene acceptors

“…The electron mobilities of ITOIC-2F, BFT-3D, and BFTT-3D amorphous thin lms were evaluated by a multiscale simulation based on quantum chemical calculations, molecular dynamics (MD) simulations, and Monte Carlo (MC) calculations, as detailed simulation processes were described in our previous works. 43,52,53 The geometry of ITOIC-2F, BFT-3D, and BFTT-3D are optimized using the quantum chemical calculations as mentioned above. Gromacs 5.1.4 molecular dynamic (MD) simulation package 54 is used to accomplish the MD simulations for all systems.…”

“…In our previous work, we demonstrated that uorination can effectively inverse the electrostatic potential and produce intermolecular F-p interactions to improve electron mobilities in the ITOIC-2F amorphous lm. 43 Therefore, we utilized di-uorinated 1,1-dicyanomethylene-3-indanone as the electronwithdrawing end groups to construct new FREAs. To break the inherent planar structural characteristics of most existing FREAs, which may reduce the degree of phase separation, we used a central triptycene hub as a core structure to design threebladed propeller-shaped FREAs.…”

“…These amorphous lms were used to construct the molecular dimer for electron transport networks as described in our early studies. 43,52,53 To investigate the transfer integral of the whole dimers in these amorphous lms, we showed the normalized distribution of the transfer integral (V) of whole system of BFT-3D and BFTT-3D in Fig. 6(b).…”

“…29,41 Fluorination can lead to red-shied absorptions, increased electron affinity, 42 and production of intermolecular F-p interactions, thereby increasing electron mobilities. 43 For example, ITOIC-2F utilizing di-uorinated 1,1-dicyanomethylene-3-indanone as end groups exhibit a high PCE of 12.17% combined with a polymer donor PBDB-T. 41 All these benets result in PCE of 15% 12 and 16% 11 of currently reported OSCs.…”

High Efficiency Deep‐Blue Phosphorescent Organic Light‐Emitting Diodes with CIE x, y (≤ 0.15) and Low Efficiency Roll‐Off by Employing a High Triplet Energy Bipolar Host Material

“…However, most of the PHOLEDs employ unipolar host materials, which results in moderate charge transportation and inferior recombination efficiency. To overcome this issue, hosts with bipolar nature with high E T are more desirable . Until now, the most successful strategy for the development of bipolar host material is to combine the donor (D) and acceptor (A) units in order to achieve a broad recombination zone and balanced charge in emitting layer (EML), which could result in the high performance, that is highly sought after .…”