Photostability of colloidal single photon emitter in near-infrared regime at room temperature

The photostability of a colloidal single photon emitter in near-infrared regime at room temperature is investigated.The fluorescence lifetime,blinking phenomenon,and anti-bunching effect of a single CdTeSe/ZnS quantum dot with an emission wavelength of 800 nm at room temperature are studied.The second-order correlation function at zero delay time is much smaller than 0.1,which proves that the emission from single quantum dots at 800 nm is a highly pure single-photon source.The effects of the irradiation duration on the fluorescence from single quantum dots are analyzed.The experimental results can be explained by a recombination model including a multi-nonradiative recombination center model and a multi-charged model.

Strong coupling between colloidal quantum dots and a microcavity with hybrid structure at room temperature

The interaction between light and matter has always been the focus of quantum science, and the realization of truly strong coupling between an exciton and the optical cavity is a basis of quantum information systems. As a special semiconductor material, colloidal quantum dots have fascinating optical properties. In this study, the photoluminescence spectra of colloidal quantum dots are measured at different collection angles in microcavities based on hybrid refractive-index waveguides. The photon bound states in the continuum are found in the low–high–low refractive-index hybrid waveguides in the appropriate waveguide width region, where the photoluminescence spectra of colloidal quantum dots split into two or more peaks. The upper polaritons and lower polaritons avoid resonance crossings in the systems. The Rabi splitting energy of 96.0 meV can be obtained. The observed phenomenon of vacuum Rabi splitting at room temperature is attributed to the strong coupling between quantum dots and the bound states in the continuum.