Strongly confining bare core CdTe quantum dots in polymeric microdisk resonators

We report on a simple route to the efficient coupling of optical emission from strongly confining bare core CdTe quantum dots (QDs) to the eigenmodes of a micro-resonator. The quantum emitters are embedded into QD/polymer sandwich microdisk cavities. This prevents photo-oxidation and yields the high dot concentration necessary to overcome Auger enhanced surface trapping of carriers. In combination with the very high cavity Q-factors, interaction of the QDs with the cavity modes in the weak coupling regime is readily observed. Under nanosecond pulsed excitation the CdTe QDs in the microdisks show lasing with a threshold energy as low as 0.33 μJ.