Scattering and dephasing of excitonic polaritons in CuCl

Abstract

We study the energy and intensity dependence of the dephasing time T2 of the polarization in CuCl inside an excitonic resonance by a femtosecond four-wave mixing technique at 5 K. We first compare results obtained on bulk material and on epitaxial films of different thicknesses for a backward-scattering configuration. This configuration is most sensitive to the region close to the surface of the samples. In bulk material, the coherence properties of the polarization are mainly limited by recombination processes and scattering with acoustic phonons while they are in addition influenced by scattering with impurities and/or imperfections in the epitaxial films. In these films, in a transmission configuration, the polarization dephases less rapidly than it appears in retrodiffusion, indicating the importance of surface recombination processes and of the polariton propagation.

Growth of CuCl thin films by magnetron sputtering for ultraviolet optoelectronic applications

“…11 The high exciton binding energy, the exciton emission in UV, and the close lattice matching with Si make CuCl a potential candidate for Si based UV/blue emitting devices. There are a few reports on the growth mechanisms of the epitaxial CuCl layers on a number of substrates [12][13][14][15][16][17][18] focusing the fundamental growth process and interfacial analysis. The present investigation steps forward to the growth and characterization of a CuCl films mainly for UV optoelectronic device fabrication.…”

Structural and optoelectronic properties of sputtered copper (I) chloride

“…Epitaxial growth of CuCl thin films on various substrates such as GaP 5 , MgO [6][7][8] and CaF 2 8,9 by molecular epitaxy and thermal evaporation 10 has been reported. One research group has analysed the growth of CuCl on Si and GaAs focusing on the interface reactions.…”