Inter-Dot Distance Dependence of Photoluminescence Properties in CdSe Quantum Dot Systems

Abstract

We studied inter-dot distance dependence of photoluminescence (PL) properties in CdSe quantum dot (QD) systems. It is found from PL lifetime measurements that there are two types of resonance energy transfer processes between different-sized QDs; one caused by Förster-type coupling in the shorter distance region and the other by retarded light-field coupling in the longer region. It is also found that the behavior of the PL intensity as a function of the inter-dot distance resembles that of the PL lifetime, which indicates that concentration quenching can be explained by a resonance phenomenon caused by dipole–dipole interaction between same-sized QDs.