Molecular Dispersion of Conjugated Polymers via Amine Containing Additives Facilitates Coating and Preserves Solid State Emission

Conjugated polymers are promising for optoelectronic applications but suffer from aggregation-caused quenching (ACQ) in the solid state. We demonstrate that incorporating amine-based additives polyethylenimine (PEI), ethylenediamine (EDA), N -methylpyrrolidone (NMP), dimethylpiperazine (DMP), and 1-methylimidazole (1MI) into thiophene-based polymers significantly suppresses ACQ through noncovalent physical interactions. Comprehensive spectroscopic and morphological analyses reveal that amine additives enhance quantum yields up to 29.6% for P1–1MI and induce a 10-fold increase for P3-PEI, while radiative rate constants ( k r ) rise by factors of 3–6. Atomic force microscopy shows a dramatic reduction in surface roughness, with Ra decreasing from 549.8 nm in pristine P1 to 145.3 nm in P1-PEIFG, indicating improved film homogeneity and smoother morphologies. Raman spectroscopy and 2D mapping confirm enhanced chain ordering and reduced aggregation, with signal intensity increasing from ∼23,000 au in pristine P1 to ∼1.1 × 10 6 a.u. in P1-PEI. Additionally, time-dependent color evolution under varying environmental conditions sunlight, +4 °C, and −20 °C demonstrates the potential of these composites as stimuli-responsive coatings. This work presents a scalable, nondestructive strategy to tailor the optical, morphological, and environmental-response properties of conjugated polymer films, with direct implications for sensors, organic electronics, and smart coating applications. Collectively, these findings demonstrate that physically interacting amine-based additives effectively increase interchain spacing, weaken π–π interactions, and suppress aggregation in conjugated polymer solids. This research advances the current state of the art by achieving a 10-fold increase in solid-state quantum yield and establishing a quantitative mechanistic link between supramolecular organization and macroscopic homogeneity through Raman 2D mapping, while introducing dynamic stimuli responsiveness.