Unidirectional ultrafast photon emission from quantum dots mediated by plasmonic hybrid nanoantennas

Weak intensity, low emission rate and poor emission directionality are three main challenges of quantum emitters. Here, we report on realizing enhanced photon emission from quantum dots mediated by plasmonic hybrid nanoantennas. Firstly, a plasmonic hybrid structure is proposed, where a silver nanocube is positioned at the center of a metallic concentric-ring structure, to simultaneously enhance the emission directionality and the decay rate of quantum dots embedded in the vertical nanogap while maintaining a high quantum efficiency. Secondly, a crystalline spherical silicon nanoparticle on metal nanoantenna is realized that can largely enhance the spontaneous emission intensity and the emission decay rate. A high quantum efficiency of over 80% is obtained. These hybrid nanoantennas can be combined with various nanoscale optical emitters and easily extended to form large area light-emitting devices for applications such as advanced display and wireless optical communication.