Exciton-plasmon interaction in hybrid quantum dot/metal cluster structures fabricated by molecular-beam epitaxy

Hybrid structures consisting of InAs/AlGaAs quantum dots and In clusters on the surface separated by an AlGaAs spacer with a specified thickness are investigated. The enhancement of the photoluminescence signal in the long-wavelength region manifesting itself in the appearance of a new narrow emission line is observed. This line is absent in the control structure with a quantum-dot array and no metal clusters. It also disappears with increasing thickness of the dielectric spacer between the layers. These results are explained in terms of a model taking into account the resonance interaction of excitons in quantum dots with localized surface plasmons in metal clusters.