Impact of alloy-like phase on energy loss mitigation in multi-component organic photovoltaics

The multi-component strategy has proven effective in advancing the performance of organic photovoltaics(OPVs),enhancing photocurrent andfill factor through spectral complementarity and morphology optimization.However,the open-circuit voltage(VOC)mechanism in multi-component systems lacks systematic investiga-tion.In this study,we explore the influence of alloy-like phases on energy level distribution and energy loss mechanisms in multi-component OPVs.Appropriate modulation of donor alloy-like phases maintains the original intermolecular stack-ing,enhances component compatibility,reduces acceptor aggregation,and improves acceptor phase purity,mitigating non-radiative recombination losses.Additionally,suitable alloy-like phase modulation elevates charge transfer(CT)states,reducing the gap between CT and local exciton state,lowering reorganization energy,and alleviating radiative recombination loss below the bandgap.Through synergistic optimization(layer-by-layer method with solid additive),ternary devices based on Y6 acceptor achieve a notable 19.41%power conversion efficiency,offering new insights for the analysis of the energy loss of the multi-component OPVs.