2024/12/14 by Ali Al-Jaaidi, Josene M. Toldo, Mario Barbatti · 1 voice
Chemistry · Physics and Astronomy · Engineering · #Photochemistry and Electron Transfer Studies #Spectroscopy and Quantum Chemical Studies #Organic Electronics and Photovoltaics
paper · pdf · doi:10.1002/jcc.27547
Diketopyrrolopyrroles (DPPs) have attracted attention for their potential applications in organic photovoltaics due to their tunable optical properties and charge-carrier mobilities. In this study, we investigate the excited-state dynamics of a DPP dimer using time-dependent density functional theory (TDDFT) and nonadiabatic molecular dynamics simulations. Our results reveal a near-barrierless hydrogen migration state intersection that facilitates ultrafast internal conversion with a lifetime of about 400 fs, leading to fluorescence quenching. Electronic density analysis along the relaxation pathway confirms a hydrogen atom transfer mechanism. These findings highlight the critical role of state intersections in the photophysical properties of DPP dimers, providing new insights for the design of functionalized DPP systems aimed at suppressing nonradiative decay for enhanced performance in photovoltaic applications.