Surface-ligand-dependent excited-state dynamics in aqueous CuInSe2/ZnS quantum dot–chlorophyll assemblies

Abstract

In this study, CuInSe 2 /ZnS quantum dots (QDs) are synthesized via a one‐pot aqueous route and interfaced with chlorophyll to investigate ligand‐dependent excited‐state interactions. The QDs exhibited broad emission between 500–800 nm and long photoluminescence lifetimes with absolute PLQY up to 33.9%. Following the hybridization process, time‐resolved photoluminescence (TRPL) is measured. The results indicated a significant reduction in the chlorophyll‐like component's lifetime, suggesting dynamic excited‐state quenching consistent with Förster‐type energy transfer and/or photoinduced charge transfer. Crucially, analysis of lifetime amplitudes uncovered a ligand‐dependent partitioning between fast quenched and long‐lived QD‐associated emissive pathways: short thiol ligands (3‐MPA and NAC) strongly suppressed and accelerated the long‐lived QD contribution, whereas L‐glutathione (L‐GSH) progressively restored a dominant long‐lived QD‐associated component with increasing QD loading. These results support that surface ligand chemistry provides an effective handle to regulate excited‐state coupling and emission‐pathway partitioning in aqueous QD–chlorophyll hybrid systems.