Effects of surface ligands on the charge memory characteristics of CdSe/ZnS nanocrystals in TiO2 thin film

摘要

harge memory characteristics have been systematically studied based on colloidal CdSe/ZnS nanocrystal quantum dots (QDs) embedded in similar to 50 nm-thick TiO2 film. Ligand-capped QDs showed negligible electron charging effect, implying that the electron affinity of QDs was significantly decreased by surface dipole layer surrounding QDs. In contrast, the hole charging was affected by the carrier injection blocking effect of the surface ligands. Efficient electron and hole charging characteristics were realized by removing the surface ligands via H-2 plasma treatment.