Fluorescence Energy Transfer from Doped to Undoped Quantum Dots

We report here the fluorescence energy transfer between two types of inorganic semiconductor nanocrystals: one is doped (d-dots) with optically active transition metal ion and other one is the undoped quantum dots (q-dots). While the two types of undoped quantum dots do not show significant energy transfer, the doped quantum dots under similar conditions show efficient energy transfer to the undoped one. The difference in the lifetime makes the doped quantum dots as donor for quantum dots. Exploring Cu-doped and Mn-doped d-dots as donor with the suitable size of CdSe q-dots as acceptor, we report here a detailed study of d-dot to q-dot energy transfer and investigate the possible mechanism.