Anti-parallel coupling of Quantum Dots with an Optical Near-Field Interaction

Abstract

We report the direct observation of optically forbidden energy transfer between cubic CuCl quantum dots via an optical near-field interaction using time-resolved near-field photoluminescence (PL) spectroscopy. The energy transfer time and exciton lifetime were estimated from the rise and decay times of the PL pump-probe signal, respectively. We found that the exciton lifetime increased as the energy transfer time fell, which strongly supports the notion that near-field interaction between QD makes the anti-parallel dipole coupling. Namely, a quantumdots pair coupled by an optical near field has a long exciton lifetime and optically forbidden features due to its anti-parallel electric dipole pair.