The Polymer Society of Korea

Abstract

NFAs demonstrate superior efficiency by minimizing energy losses during charge dynamics. To fully harness these materials' potential, optimizing morphology through solvent volatility control offers a promising approach. PY-IT, a polymer-based NFA, exhibits greater morphological tunability than
others, resulting in strong solvent dependence. PY-IT shows dramatically different photoluminescence behavior depending on solvent volatility. In highly volatile chloroform, various peaks of unknown origin were observed beyond typical vibronic transitions, while tetrahydrofuran and dichlorobenzene exhibited extreme peak shifts. This study elucidates the molecular origins of these emission behaviors and establishes optimization strategies for device performance. We analyzed photophysical processes through structural characterization and spectroscopic techniques, investigating phonon via low T PL and tracking ultrafast charge dynamics using fs transient absorption.