Time-resolved photoluminescence study of the red emission in nanoporous SiGe alloys

Citation
S. Lebib et al., Time-resolved photoluminescence study of the red emission in nanoporous SiGe alloys, J LUMINESC, 80(1-4), 1998, pp. 153-157
Citations number
8
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
JOURNAL OF LUMINESCENCE
ISSN journal
00222313 → ACNP
Volume
80
Issue
1-4
Year of publication
1998
Pages
153 - 157
Database
ISI
SICI code
0022-2313(199812)80:1-4<153:TPSOTR>2.0.ZU;2-M
Abstract
Porous Si1-xGex (PSiGe) layers with efficient room temperature visible phot oluminescence (PL) were elaborated by anodical etching from p-type doped ep itaxial layers with Ge contents from 5 to 30%. The luminescence is characte rised by a broad PL band centred at 1.8 eV. Time resolved photoluminescence decay is studied in porous silicon germanium as a function of germanium co ntent, temperature, emission energies and surface passivation. The PL decay line shape is well described by a stretched exponential in all cases. The effective lifetime at low temperature in as prepared porous Si1-xGex is 400 mu s, i.e. an order of magnitude less than in porous silicon. After the fo rmation of a 20 Angstrom thick oxide surface layer we observe a decrease of the effective lifetime to 20 mu s at T = 4 K. (C) 1999 Published by Elsevi er Science B.V. All rights reserved.