Molecular orientation stands as the quintessential hallmark of conjugated self-assembled monolayers (SAMs), which have recently catalyzed noteworthy advancements in organic photovoltaics (OPVs). Nevertheless, an unambiguous understanding of these directional arrangements and their impact on optoelectronic properties remains elusive. To address this issue, herein three SAMs with representative orientations, i.e., edge-on (BCZ-1), tilt-on (4PACz) and face-on (BCZ-2) are meticulously designed. These orientations have been rigorously validated by sum frequency generation vibrational spectroscopy and first-principles calculations. Remarkably, an unequivocal correlation between the molecular orientation and the device performance is discerned. Particularly, the edge-on oriented BCZ-1 exhibits the largest dipole moment normal to the electrode, accompanied by a dense and uniform coverage. These features collectively contribute to its strongest work function increment for ultra-fast hole extraction and minimum interfacial carrier recombination. As a result, a champion power conversion efficiency of 19.93% is achieved in devices based on BCZ-1 with D18:L8-BO as the active layer, representing one of the highest values reported for binary bulk heterojunction OPVs. Besides, BCZ-1 shows great potential for practical applications due to its superior up-scalability and enhanced device shelf-stability. Overall, this work offers in-depth insights into the orientation behaviors of SAMs, opening new avenues to unlock the efficiency potential of OPVs.
Luobin She,Chuankai Zou,Kaihang Yang,Xiaomin Kang,Lin Chen,Jing Tang,Zhenye Li
All-polymer solar cells (all-PSCs) demonstrate splendid advantages of thermal and mechanical stability. Nevertheless, the rock-ribbed trade-off between the crystallinity and phase separation scale of donor/acceptor (D/A) hinder the power conversion efficiency (PCE) improvement of all-PSCs. Here, a novel two-dimensional transition-metal phosphorus trichalcogenides (TMPTCs) namely Cd 0.85 PS 3 Li 0.3 is intelligently designed and synthesized, and firstly employed as a nanoparticle dopant for PBDB-T:N2200-based all-PSCs. The two-dimensional Cd 0.85 PS 3 Li 0.3 possess enormous surface area that can serve as the nucleation center, inducing the crystallinity of D/A without influencing the original phase separation. Such feature significantly boosted the charge transport, PCE (from 7.18% to 8.79%) and stability of PBDB-T:N2200-based device. Moreover, the Cd 0.85 PS 3 Li 0.3 nanoparticle dopant was proved to be universal in non-fullerene small molecule acceptor (NFSMA)-based organic solar cells (OSCs), for which the PCE was boosted from 15.05% to 17.27% for PM6:L8-BO-based OSCs and from 17.29% to 19.10% for D18:L8-BO-based OSCs. These observations exemplify the significance of two-dimensional TMPTCs nanoparticle dopant as a tool for breaking the rock-ribbed trade-off between the crystallinity and phase separation scale of D/A in OSCs, which may open up a special field for making two-dimensional TMPTCs work in a unprecedented way in OSCs.
危险品化学品经营许可证（带存储）