Purcell effect for CdSe∕ZnSe quantum dots placed into hybrid micropillars

Abstract

This letter reports the observation of the Purcell effect for CdSe∕ZnSe quantum dots located in a hybrid micropillar. The sample consist of a λ∕2-ZnSe cavity sandwiched between two SiO2∕TiO2 Bragg reflectors. Time-resolved photoluminescence (PL) measurements on a series of single-quantum dots were used to probe the Purcell effect in a 1.1μm diameter pillar. A three-fold enhancement of quantum-dot spontaneous emission rate is observed for quantum dots in resonance with excited degenerated modes of the pillar. The variation of the PL decay shortening from dot to dot is interpreted calculating the theoretical maximal Purcell factor for the different modes resonant with the dots.