Exciton-exciton annihilation in organic polariton microcavities

Publication Type:

Journal Article

Source:

Phys. Rev. B Condens. Matter, American Physical Society, Volume 82, Issue 11, p.113106 (2010)

ISBN:

0163-1829

Keywords:

2010, 2013 and earlier

Abstract:

We investigate the incoherent diffusion of excitons in thin films (5.1±0.1 nm thick) of a highly absorbing J-aggregated cyanine dye material (106
cm−1 absorption constant) as the excitonic component of a polariton
microcavity. Under high-intensity pulsed laser excitation, the
J-aggregated molecular films exhibit significant exciton-exciton
annihilation, indicating a large exciton diffusion radius of more than 100
nm. When the material is strongly coupled to a cavity, the polaritonic
structure also shows exciton-exciton annihilation, which is a competing
process against the establishment of a threshold population of polaritons
needed for polariton lasing. This study suggests that exciton-exciton
annihilation is a loss process which can significantly increase the lasing
threshold in polariton microcavities.