Exciton–Polariton Dispersion of Thin Anthracene Crystals in the Thickness Range of 3 to 0.1 μm

Abstract

The effect of crystal thickness on the exciton polariton dispersion of anthracene is studied by using melt-grown crystals with thicknesses ranging from 3 to 0.1 pm. The refractive indices in the vicinity of the first-exciton resonance are determined for the polarization E /I b and E 11 a by analyzing interference fringes observed in the reflection spectra at 10 K. In contrast to the results reported previously, it is found that the dispersion property is independent of the crystal thickness at least down to 0.1 pm. A comparison of the present result with the thickness-dependent dispersion formula is presented.Der EinfluR der Kristalldicke auf die Polaritondispersion von Anthracen wird an Kristallen aus der Schmelze mit einer Dicke von 3 bis 0,l pm untersucht. Die Brechungsindizes in der Nahe der ersten Exzitonenresonanz werden durch die Analyse der Interferenzstreifen fur die Polarisation E 11 b und E 11 a aus dem Reflexions-Spektrum bei 10 K bestimmt. Im Gegensatz zu friiher gegebenen Ergebnissen wird gefunden, daR die Dispersionseigenschaften unabhangig von der Kristalldicke bis herunter zu 0,l pm sind. Ein Vergleich der vorhandenen Ergebnisse mit der von dickeabhangigen Dispersionsformeln wird vorgestellt.

Cavity modes of exciton–polaritons in an organic crystal with distributed Bragg reflectors

“…Dispersion was obtained from the peak positions. It was found, however, that the dispersion is slightly different from the dispersion curve reported in the previous research [5]. This difference is caused by a decrease of the effective cavity length with the photon energy approaching exciton resonance.…”

“…4 is the curve of the bpolarized exciton-polariton in anthracene, obtained through the previous study [5]. The polariton's parameters are as follows: the transverse-exciton energy E T ¼ 3:119 eV; the longitudinal-transverse splitting energy D LT ¼ 51 meV; and the background dielectric constant e ¼ 3:2.…”

Cavity Polaritons in a Single-Crystalline Organic Microcavity Prepared at Room Temperature Using a Simple Solution Technique

“…14,15) In the microcavities, crystalline anthracene films were grown using a melting process at 240 C in nanoscale gaps between two joined distributed Bragg reflectors (DBRs). 10,16) In the melting technique, strain in crystalline films is likely caused by thermal expansion during the fabrication process. In this paper, we have shown that single-crystalline anthracene films can be easily grown using a simple solution technique in a microcavity gap at RT.…”

Optical responses in single-crystalline organic microcavities

“…1 for polarizations parallel to the (a) [1 0 0] and (b) [0 1 0] directions in the anthracene crystal, where E a ex ¼ 3:145 eV and E b ex ¼ 3:122 eV are the respective exciton energies [6]. The exciton states result from two polarized exciton transitions due to Davydov splitting [7].…”

“…Thickness of anthracene film was determined by numerical fitting of transmission spectra on the basis of the transfer matrix theory (TMT) [8]. The refractive index of anthracene for the TMT calculation is determined from the bulk polariton dispersion in the lower polariton region using a one-oscillator polariton model [5,6]:…”