초록 |
We report synthesis of CdSe/ZnSe core/shell nanorystals via direct Cd-to-Zn cation exchange in CdSe nanocrystals. The cation exchange can be achieved by HSAB theory, which can control binding strength between cation and ligand. Cd-to-Zn cation exchange increases photoluminescence (PL) quantum yield because of inorganic passivation and additional ligand passivation onto shell material. CdSe/ZnSe core/shell nanocrystals have quasi type II band alignment. Lifetime of CdSe/ZnSe core/shell nanocrystals is increased, compared with CdSe nanocrystals. UV-vis spectroscopy, PL spectroscopy, FT-IR, XRD, and PL decay are utilized for the characterization of cation-exchanged CdSe/ZnSe core/shell nanocrystals. This research suggests that facile synthesis is possible via cation exchange, and the materials, which have longer lifetime, are applied to photocatalysis. |