Cosolvent-driven exciton delocalization and dual dissociation pathways enable high-efficiency inverted all-polymer solar cells
Journal
Chemical Engineering Journal
Journal Volume
544
Start Page
179165
ISSN
13858947
Date Issued
2026-09-15
Author(s)
Chang, Jia-Fu
Ahn, Hui Chan
Barma, Sunil V.
Yeh, Cheng-Yu
Tseng, Yu-Cheng
Kwon, Hyun Min
Jeon, Hyerin
Cheng, Hsu-Tzu
Kim, Bumjoon J.
Jo, Sae Byeok
Abstract
This study proposes a cosolvent strategy to optimize the morphology and performance of all-polymer solar cells (All-PSCs). By partially replacing chloroform with eco-friendly solvents (tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-MeTHF), and 3-methyltetrahydrofuran (3-MeTHF)), the solution-to-film transition and phase separation dynamics are optimized through modulating solvent evaporation kinetics. This enhances polymer miscibility, reduces domain size, strengthens molecular stacking, and promotes favorable vertical alignment in the photoactive layer. Comprehensive characterization confirms that devices fabricated using THF and 2-MeTHF cosolvents exhibit balanced charge transport, reduced recombination losses, and more efficient charge separation. Notably, ultrafast transient absorption spectroscopy further unveils dual exciton dissociation pathways and efficient interfacial hole transfer, highlighting the critical role of cosolvent-driven exciton delocalization control—a phenomenon rarely reported in All-PSCs. This study presents a simple strategy to advance the performance and sustainability of All-PSCs through cosolvent design and morphology control.
Subjects
all-polymer solar cells
charge carrier dynamics
Exciton delocalization
green cosolvent
morphology control
Publisher
Elsevier B.V.
Type
journal article