Elementary\nExciton Processes of InP/ZnS Quantum Dots\nUnder Applied Pressure

In colloidal quantum dots (QDs), excitons are confined\nwithin nanoscale\ndimensions, and the relaxation of hot electrons occurs through Auger\ncooling. The behavior of hot electrons is evident under ambient pressure.\nNanocrystal characteristics, including their size, are key to determining\nhot electron behavior because they serve as the stage. Applying pressure\nto materials can effectively modify this stage by providing a means\nto reversibly control interatomic distances. Unlike the behavior under\nambient conditions, the pressure-dependent behavior remains unclear.\nIn this study, InP/ZnS QDs were synthesized, and their pressure-dependent\nultrafast carrier dynamics were analyzed using fs-transient absorption\nspectroscopy. The hot electron relaxation remained nearly constant\nup to the threshold pressure, suggesting constant interaction between\nelectrons and holes. However, above this threshold, the hot electron\nrelaxation was accelerated by trapping from higher excited states.\nThis study contributes to establishing a fundamental understanding\nof the pressure-dependent behavior of hot electrons in QDs.