No abstract

A fullerene additive adjusts the miscibility between donor and acceptor for morphology optimization and reduces bimolecular recombination, assisting significant improvement of fill factor and efficiency.

Due to the barrierless free charge generation, low charge trapping, and high charge mobilities, the PM6:Y6 organic solar cell (OSC) achieves excellent power conversion efficiency (PCE) of 15.7%. However, the...

Morphology is a critical factor to determine the photovoltaic performance of organic solar cells (OSCs). However, delicately fine-tuning the morphology involving only small molecules is an extremely challenging task. Herein, we demonstrate a simple, generic, and effective concentration induced morphology manipulation approach to prompt both the state-of-the-art thin-film BTR-Cl:Y6 and thick-film BTR:PC 71 BM all-small-molecule (ASM) OSCs to a record level. The morphology is delicately controlled by subtly altering the prepared solution concentration but maintaining the identical active layer thickness. The remarkable performance enhancement achieved by this approach mainly results from the enhanced absorption, reduced trap-assistant recombination, increased crystallinity, and optimized phase-separated network. These findings demonstrate that concentration induced morphology manipulation strategy can further propel the reported bestperforming ASM OSCs to a brand-new level, and provide a promising way to precisely control the morphology towards high-performance ASM OSCs.

Single junction binary all-small-molecule (ASM) organic solar cells (OSCs) with power conversion efficiency (PCE) beyond 14% are achieved by using non-fullerene acceptor Y6 as the electron acceptor, but still lag behind that of polymer OSCs. Herein, an asymmetric Y6-like acceptor, BTP-FCl-FCl, is designed and synthesized to match the recently reported high performance small molecule donor BTR-Cl, and a record efficiency of 15.3% for single-junction binary ASM OSCs is achieved. BTP-FCl-FCl features a F,Cl disubstitution on the same end group affording locally asymmetric structures, and so has a lower total dipole moment, larger average electronic static potential, and lower distribution disorder than those of the globally asymmetric isomer BTP-2F-2Cl, resulting in improved charge generation and extraction. In addition, BTP-FCl-FCl based active layer presents more favorable domain size and finer phase separation contributing to the faster charge extraction, longer charge carrier lifetime, and much lower recombination rate. Therefore, compared with BTP-2F-2Cl, BTP-FCl-FCl based devices provide better performance with FF enhanced from 71.41% to 75.36% and J sc increased from 22.35 to 24.58 mA cm −2 , leading to a higher PCE of 15.3%. The locally asymmetric F, Cl disubstitution on the same end group is a new strategy to achieve high performance ASM OSCs.

A "s-hole''-containing small molecule is used as an additive for organic solar cells 16.5% efficiency organic solar cells are achieved with additive engineering Excellent stability and easy processability are obtained with the additive

Attributed to the rapid development of benzodithiophene (BDT) centered small molecule donors, all small molecule organic solar cells (ASM-OSCs) have achieved comparable power conversion efficiency (PCE) (>15%) along with high...

The rapid development of non-fullerene acceptors (NFAs) has placed increasing demands on polymer donors and current-available top-performing polymer donors still have space to optimize to work perfectly with the state-of-the-art...