Research Paper: Chemical structure and processing solvent of cathode interlayer materials affect organic solar cells performance
Summary
Photostability of PM6:Y6 OSCs with PDINO (MeOH) and F-PDIN-EH (MeOH, 1-butanol, heptane) under N₂ and ambient: PDINO/MeOH shows the longest lifetime; F-PDIN-EH/heptane degrades fastest. Measured under ISOS L-1 using a calibrated AM1.5 setup (Litos Lite).
This study compares PDINO with a fluorinated PDI interlayer (F-PDIN-EH) processed from methanol, 1-butanol, or heptane to see how CIL chemistry and solvent choice affect OSC efficiency and stability. Overall efficiencies are comparable, but stability diverges sharply: PDINO is more stable; F-PDIN-EH degrades faster, with heptane-processed devices performing worst due to increased surface recombination and mobility imbalance. Measurements followed ISOS D-1/L-1/T-1 and included TPV, TPC, EIS, C–V, SCLC mobility, AFM, UV-vis, and FTIR. Paios was used for TPV/TPC/EIS/C–V and Litos Lite for dark J–V and stability/illumination tests.
Publication Details
Authors: Souk Y. Kim; Pimmada Sawangwong; Colton Atkinson; Gregory C. Welch; Nutifafa Y. Doumon.
Journal: Journal of Materials Chemistry C (2025).
Why it matters
Solvent choice for CILs directly drives OSC stability. PDINO in methanol stays stable longest; F-PDIN-EH devices are consistently less stable, with heptane the worst and 1-butanol the best among the F-series.
Heptane-processed F-PDIN-EH degrades fastest due to increased surface recombination and charge-mobility imbalance, confirmed by TPV/TPC, light-intensity J–V, EIS and SCLC.
Green-solvent transitions must be solvent-aware: stability hinges on solubility, film formation, balanced transport and controlled interfacial energetics.
Robust ISOS D-1/L-1/T-1 methodology plus Paios and Litos Lite provides reproducible stability and charge-dynamics evidence for materials/process decisions
Fluxim Tools Used
Paios: TPV, TPC, EIS, and capacitance–voltage (Mott–Schottky) measurements with white-LED excitation.
Litos Lite: Dark J–V of electron-only devices; stability and light-intensity Jsc/Voc per ISOS D-1/L-1/T-1 with an AM 1.5 simulator.