This study aims to investigate the excited-state dynamics governing charge generation and recombination processes in organic photovoltaic (OPV) materials to better understand their efficiency-limiting mechanisms. Time-resolved photoluminescence (TRPL) and transient absorption spectroscopy (TAS) were employed to examine exciton lifetimes, charge transfer rates, and recombination behavior in donor–acceptor blends based on P3HT:PCBM and PTB7:PC71BM systems. The spectroscopic data reveal that the charge separation efficiency strongly depends on the morphology and energetic alignment between donor and acceptor components. TRPL measurements indicate that optimized blend morphology leads to extended exciton lifetimes and reduced nonradiative recombination, while TAS analysis confirms the presence of long-lived charge-separated states contributing to photocurrent generation. These findings provide crucial insights into the relationship between molecular structure, electronic interactions, and photophysical responses in OPV systems. The study concludes that controlling the nanoscale phase distribution and interfacial energy offsets is essential to improving charge separation and overall device performance.
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