Photoinduced Electron Transfer System from Cesium Lead Bromide Quantum Dots to Naphthalenediimide Supramolecular Polymers

Supramolecular polymers (SPs) formed via the stacking of π-conjugated molecules are attractive nanomaterials because of their potential optoelectronic properties derived from the non-covalent interaction between the π-skeletons. Especially, SPs possessing naphthalenediimide (NDI) core units can act as superior electron acceptors due to their deep lowest unoccupied molecular orbital (LUMO). Interaction of such SP with electron donors can realize a charge transfer system, but this has not been established. Herein, we report a photoinduced electron transfer system from cesium lead bromide quantum dot (QD) as an electron donor to SP composed of cholesterol-functionalized NDI derivatives. The supramolecular polymerization in a non-polar solvent was analyzed in detail via microscopic and spectroscopic analyses. Upon mixing the SP with QDs, the photoluminescence intensity and lifetime of QDs decreased significantly, indicating efficient photoinduced electron transfer from QD to SP.