Photoluminescence of CdSe/ZnS core/shell quantum dots enhanced by energy transfer from a phosphorescent donor

We demonstrate exciton energy transfer from a thin film of phosphorescent dye fac tris(2-phenylpyridine) iridium (Ir(ppy)(3)) to a monolayer of colloidal CdSe/ZnS core/shell quantum dots (QDs). The energy transfer is manifested in time-resolved photoluminescence (PL) measurements as elongation of the QD PL time constant from 40 to 400 ns, and a concomitant 55% increase of time-integrated QD PL intensity. The observed PL dynamics are shown to be dominated by exciton diffusion within the Ir(ppy)(3) film to the QD layer. (c) 2006 Elsevier B.V. All rights reserved.