Pool-Frenkel thermoelectric modulation of exciton photoluminescence in GaSe crystals


Ertap H., Mamedov G. M. , Karabulut M., Bacioglu A.

JOURNAL OF LUMINESCENCE, vol.131, no.7, pp.1376-1379, 2011 (Peer-Reviewed Journal) identifier identifier

  • Publication Type: Article / Article
  • Volume: 131 Issue: 7
  • Publication Date: 2011
  • Doi Number: 10.1016/j.jlumin.2011.03.037
  • Journal Name: JOURNAL OF LUMINESCENCE
  • Journal Indexes: Science Citation Index Expanded, Scopus
  • Page Numbers: pp.1376-1379

Abstract

Effect of external field on the exciton photoluminescence of GaSe crystals has been investigated and it has been observed that the PL is quenched with the applied field. The changes observed in the PL spectra have been analyzed with impact exciton, Franz-Keldysh and Pool-Frenkel effects. From the analyses of the experimental data, it has been found that the intensity of direct free, indirect free and bound exciton peaks decreased exponentially with the square root of applied field as I similar to exp-beta root E. The energy positions of emission peaks were found to shift to longer wavelength with the applied field as Delta E similar to beta root E. From these findings, the Pool-Frenkel thermoelectric field effect is seen to be the dominant mechanism in the variation of exciton PL with the applied field even though the impact exciton and Franz-Keldysh effects contribute. (C) 2011 Elsevier B.V. All rights reserved.