Mixed Ionic–Electronic Memory in a Conjugated Polymer Composite for Retrospective Optical Event Reconstruction
Year: 2026
Type: preprint
Abstract: Coupling a light-responsive conjugated polymer to an ionic matrix and oxide interfaces offers a materials strategy for retaining complementary information about completed optical events. A PEDOT:PSS/Nafion/TiO 2 composite implements this approach through an irradiance-dependent conductance amplitude and a wavelength-dependent fading trajectory. At matched nominal polymer loading, TiO 2 incorporation reduces the light-OFF amplitude by 70–77% while extending the half-decay time by 1.56–2.01-fold. Post-illumination optical spectra reveal persistent, composition-dependent changes consistent with electronic-state redistribution coupled to slower matrix and interfacial relaxation. The peak conductance change remains linear with irradiance over 10–40 mW cm −2 (R 2 = 0.9981–0.9993), enabling 91.7% leave-one-condition-out wavelength accuracy and an irradiance mean absolute error of 0.86 mW cm −2 . Same-batch devices show strong kinetic fidelity (median relaxationtime coefficient of variation = 10.02%), but zero-shot transfer to a device from an independently prepared batch fell to 58.3% wavelength accuracy (7/12; p = 0.066 versus three-class chance), making cross-batch kinetic variability the principal barrier to calibration-free transfer. With readout delay withheld, 50 s segments yield 88% wavelength accuracy and a conditional event-age error of 5.5 s. This work demonstrates retrospective decoding of completed optical events in a conjugated polymer composite. A stored conductance peak and a post-illumination relaxation trajectory enable calibrated reconstruction of irradiance, wavelength, and elapsed event age.
Source: ChemRxiv
Authors: Md Al Raihan, Tian Xia, Michael S. Freund
Institution: Dalhousie University
Language: English
Subfield: Polymers and Plastics
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7221067834