Exploring the photodynamic profile of laser-generated exciplex from a conjugated polymer

The mechanism of the exciplex formation between PDDCP and THF species. [Display omitted] •Spectral properties of PDDCP in THF for different concentrations were studied.•The band gap energy is inversely propositional to concentrations of the polymer.•The photoluminescence spectra of PDDCP in THF showed two distinguished bands.•These bands refer to the exciplex and excimer formations.•The ASE properties of PDDCP showed an exciplex band at 565 nm. In this work, we investigated the impact of the concentration on the spectral and amplified spontaneous emission spectra (ASE) of a conducting polymer of poly(2,5-di(3,7-dimethyloctyloxy) cyanoterephthalylidene) (PDDCP) in tetrahydrofuran (THF). The findings demonstrate that the absorption spectra exhibited two peaks at 330 and 445 nm across the concentration range (1–100 µg/mL). Irrespective of the optical density, altering the concentrations did not affect the absorption spectrum. Also, the analysis indicated that the polymer did not agglomerate in the ground state for any of the concentrations mentioned. However, changes in the polymer had a substantial effect on its photoluminescence spectrum (PL), likely due to the formation of exciplexes and excimers. Also, the energy band gap also varied as a function of concentration. At a certain concentration (25 µg/mL) and pump pulse energy (3 mJ), PDDCP produced a superradiant ASE peak at 565 nm with a remarkably narrow full width at half maximum (FWHM). These findings can provide insight into the optical characteristics of PDDCP, which may have potential applications in the fabrication of tunable solid-state laser rods, Schottky diodes, and solar cell applications.