Direct observation of the strength of plasmon-longitudinal optical phonon interaction in n-type GaAs

Altan H., Xin X., Matten D., Alfano R. R.

APPLIED PHYSICS LETTERS, vol.89, no.5, 2006 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 89 Issue: 5
  • Publication Date: 2006
  • Doi Number: 10.1063/1.2236300
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Middle East Technical University Affiliated: No


The screening of longitudinal optical phonons by plasmons is investigated by time-resolved visible pump-mid-infrared probe transmission measurements in a series of light to highly doped n-type GaAs wafers. The reduced relaxation of photogenerated carriers is strongly correlated to the coupling between longitudinal optical phonons and background plasmons as suggested by the variation of the phonon strength over the doping range. The critical plasmon density at which the optical phonons were effectively screened, thereby reducing the carrier relaxation, was determined to be N-c similar to 1x10(18) cm(-3). (c) 2006 American Institute of Physics.