Room Temperature Broadband Polariton Lasing from a Dye‐Filled Microcavity

Abstract

GaAs-based microcavities. [2] However, the applications of III-V and II-VI inorganic semiconductors in polaritonics are relatively limited due to the challenging growth techniques required to create wide bandgap semiconductors together with the necessity of using cryogenic temperatures to create Wannier-Mott excitons. [3,4] Organic semiconductors however comprise the broadest class of strongly coupled materials developed to date and include molecular dyes, crystalline organic molecules, oligofluorenes, and conjugated polymers. [5][6][7][8][9][10][11] Owing to the high quantum yield, large dipole moment of optical transitions and high-binding energy of excitons, organic semiconductors have permitted the physics and applications of polaritonics to be explored at room temperature. [12,13] Polariton lasing is one of the most distinctive nonlinear phenomena related to the collective behavior of exciton polaritons. In contrast to conventional photon lasers, a polariton laser does not necessitate the electronic inversion of population, but is instead driven by a stimulated relaxation to a coherent state during the process of condensation to the ground polariton state. This process has allowed polariton lasers to exhibit significantly lower thresholds compared to photon lasers that have been fabricated using the same device configuration. [14,15] Recently, we demonstrated polariton lasing in the yellow part of the spectrum in an organic microcavity containing the molecular dye bromine-substituted boron-dipyrromethene (BODIPY-Br). [5] In the present paper, we explore the incorporation of another molecular dye of the BODIPY family, namely BODIPY-G1 fluorescent dye, into a microcavity and show that by incorporating a wedged cavity-layer configuration, we can achieve strong coupling over a broad range of exciton-photon detuning conditions. Such structures allow us to controllably access different cavity lengths and thus select the energy of the ground polariton state. We then use this approach to provide evidence of polariton lasing over a broad range of wavelengths (>30 nm) utilizing a single material system.

BODIPY-Based Molecules, a Platform for Photonic and Solar Cells

“…In 2019, Sannikov et al [ 106 ] developed a material system with polariton lasing at room temperature over a broad spectral range. The system is based on molecule BODIPY-G1 ( Scheme 2 ), which is a derivative presenting high extinction coefficients and high PL quantum yield.…”

“…Reproduced from Ref. [ 106 ] with permission from 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim, Germany.…”

Entropic Mixing Allows Monomeric‐Like Absorption in Neat BODIPY Films

“…[18] BODIPYd yes in the strong coupling regime have been studied by the group of Lidzey.T hey used BODIPY derivatives dopeda t1 0-20 %i na no ptically inert polymer matrix to avoid aggregation, andb yd oing so explored the opticalp roperties [19] andt he energy transfer betweent wo derivatives. [9b] Furthermore,p olariton lasing, [20] formationo fp olariton condensates [21] andanti-stokes fluorescence [22] have been successfully shown.…”

Strong Exciton–Photon Coupling in Dye‐Doped Polymer Microcavities

“…[ 29–30 ] More importantly, the cavity lengths can be expediently controlled by changing the polymer film thicknesses, which would allow us to access different strong coupling conditions and tune the polariton emission properties. [ 31 ] Therefore, dye‐doped polymer microcavities are ideal candidates for studying the excited‐sate processes in the strong coupling regime and developing novel polaritonic devices for light emission applications.…”