Temperature dependence of the upper-branch polariton population in an organic semiconductor microcavity

Optical
Thin Film
Innovation

An IS09001:2008 & British Standard Kitemark company

Temperature dependence of the upper-branch polariton population in an organic semiconductor microcavity
 
David M. Coles
Department of Physics and Astronomy, University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH, United Kingdom
Paolo Michetti
Institute of Theoretical Physics and Astrophysics, University of Wurzburg, D-97074 Wurzburg, Germany
Caspar Clark
Helia Photonics, Rosebank Park, Livingston, West Lothian EH54 7EJ, United Kingdom
Ali M. Adawi and David G. Lidzey
Department of Physics and Astronomy, University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH, United Kingdom
 
 
abstract
We explore the distribution of polaritons along the upper polariton branch of a strongly coupled organic-semiconductor microcavity as a function of temperature following nonresonant optical excitation. Measurements of polariton emission from a high-finesse cavity containing a thin film of a J-aggregated cyanine dye were performed as a function of external detection angle and temperature and compared with the results of detailed numerical simulations.
We show that a full description of temperature-dependent upper-branch polariton emission can only be obtained by accounting for the interplay between two mechanisms that populate polariton states, namely, thermally assisted exciton scattering and direct radiative pumping of the photonic component of polariton states via the radiative decay of weakly coupled “reservoir” excitons. Our measurements provide a full description of the basic mechanisms at play in an organic microcavity, and may help guide the development of organic polariton-based devices.