Ultrastrong light-matter coupling in electroluminescent organic microcavities

Abstract In this work, we explore the effects of the ultrastrong coupling regime between light and molecular excitons on the electrical and optical properties of microcavity-OLEDs. We studied two different samples having a coupling value of 31% and 48%. The main effect of the ultrastrong interaction is on the electroluminescent emission linewidth which was only 28 meV, that is about 12-fold narrower than that of the corresponding photoluminescence of the uncoupled material and even half the linewidth of photonic (weak-coupled) microcavity working at the same wavelength.