Electronic coupling and exciton energy transfer in CdTe quantum-dot molecules

J Am Chem Soc. 2006 Aug 16;128(32):10436-41. doi: 10.1021/ja061608w.

Abstract

Stable dispersions of molecularlike aggregates of CdTe quantum dots are prepared by chemical cross-linking. Cryo-TEM images confirm the presence of cross-linked quantum dots and show that the size of the small aggregates can be controlled by the amount of cross-linker added. Optical measurements reveal two types of interdot interactions within these quantum-dot molecules: exciton energy transfer and electronic coupling. Quantitative information on the energy transfer rates in quantum-dot molecules is obtained by photoluminescence lifetime measurements. The degree of electronic coupling is dependent on the size of the quantum dots, which is supported by quantum mechanical calculations.