External Electric Field-Induced Morphological Reorganization in Degraded Organic Semiconducting Films

The long-term performance of organic electronic materials hinges on their ability to maintain structural and electronic order under environmental and device stressors. However, once morphological disorder sets in through oxidative degradation, photobleaching, or thermal cycling, recovery has traditionally been considered irreversible. Here, we present a postdegradation recovery strategy for organic semiconducting thin films using a nonchemical, noninvasive external electric field (EEF) treatment. By coupling an EEF stimulus with solvent vapor-induced softening, we induce significant nanoscale morphological reorganization, enabling the recovery of degraded crystallite orientation and promoting favorable H-aggregate formation. Grazing-incidence wide-angle X-ray scattering (GIWAXS) reveals that EEF treatment not only restores lamellar and π–π stacking but enhances edge-on crystallite alignment beyond that of pristine films. Concurrent absorption spectroscopy studies show vibronic peak shifts and intensity ratios indicative of a preferential transition toward H-aggregated domains, reflecting enhanced intermolecular interactions and more favorable charge transport pathways. Quantitative analysis via mosaicity factor (MF) mapping further confirms a narrowing of the crystallite orientation across dominant diffraction axes. This EEF-driven recovery process demonstrates a nonchemical route to reverse degradation-induced disorder and achieve postfabrication control over polymer morphology without the need for additives, thermal annealing, or irreversible chemical modifications, with broad implications for extending device lifetimes and improving the reliability of flexible organic optoelectronic technologies.