1
Return

A Binary Cathode Interlayer Coupling Dipole Regulation and Molecular Orientation Enables 20.1%-Efficient Organic Solar Cells

delete2026-08-12
delete0
PRE
AI
X
Xinqiang Zhu
X
Xin Li
S
Sein Chung
B
Byeongchan Park
H
Hyunji Lee
M
Min Zhang *
Y
Yangchao Zheng
W
Wuning Wei
J
Jingrong Zhang
L
Lixing Tan
J
Jingjing Zhao
L
Lijun Li *
K
Kilwon Cho
Z
Zhipeng Kan
DOI:10.1002/smll.75084delete
deleteOriginal
deleteOriginal request for help
deleteShare
deleteSave
Abstract

Abstract

En 中文
The performance of organic solar cells is critically influenced by electron extraction at the cathode interface, which is often limited by suboptimal energy alignment and disordered molecular packing in the cathode interlayer. Here, we demonstrate that synergistic coupling between interfacial dipole engineering and molecular orientation ordering in a binary cathode interlayer comprising an n-type small molecule (NDI-Ph) and an electron-transporting polymer (PNDIT-F3N-Br) simultaneously optimizes energy-level alignment and enhances vertical charge transport. Accordingly, the binary interlayer lowers the cathode work function to 3.23 eV, promotes face-on π–π stacking in the overlying photoactive layer, suppresses trap-assisted recombination, accelerates electron extraction (0.27 µs), and prolongs carrier lifetime (3.38 µs). As a result, single-junction organic solar cells composed of PM6:BTP-eC9 achieve a power conversion efficiency of 20.1%. Notably, the same binary cathode interlayer boosts the performance of devices comprising PM6:L8-BO to 19.5%, outperforming those with single-component interlayers, underscoring its universality across state-of-the-art active layers. This work highlights the role of dipole–ordering coupling as a fundamental design principle for high-performance interfacial layers in organic photovoltaics.
Keywords:
binary cathode interlayer
interfacial dipole
molecular orientation
non-fullerene acceptors
organic solar cells

Journal

Small cover
Small
IF:
12.1
Papers:
3.0W
Citations:
16.4W

Organization

H
huaibei normal university
Scholars:
497
Papers: 153
Citations: 0
P
pohang university of science and technology
Scholars:
549
Papers: 194
Citations: 0
G
guangxi university
Scholars:
3.2W
Papers: 1.8W
Citations: 25
S
south china university of technology
Scholars:
6.5W
Papers: 5.0W
Citations: 85
Cited Papers

Cited Papers

Citing Papers

Citing Papers