Strong coupling between colloidal quantum dots and dielectric film at room temperature

In this study, the angle-resolved photoluminescence and reflection spectra from colloidal quantum dots on materials with low-refractive-index/high-refractive-index structure at room temperature are investigated. The photoluminescence spectra for the materials split into two main spectral peaks at various angles. Different kinds of dielectric materials and different thicknesses are used to verify the PL spectral splitting phenomena. By comparing the PL spectrum and RL spectrum of dielectric materials on substrates with different refractive indexes, the PL spectral splitting is attributed to strong coupling between the quantum dots exciton and asymmetric F–P cavity formed in the low-refractive-index/high-refractive-index material. The loss of the F–P mode decreases due to the destructive interference effect.