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Carrier density and confined polaron effects in the photoluminescence of fresh and oxidized porous silicon
Author(s) -
Zou Bingsuo,
Dai Jiahua,
Xie Sishen
Publication year - 2004
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.1667
Subject(s) - porous silicon , photoluminescence , silicon , wafer , materials science , fourier transform infrared spectroscopy , analytical chemistry (journal) , polaron , chemical engineering , chemistry , nanotechnology , optoelectronics , organic chemistry , physics , quantum mechanics , engineering , electron
In this report the temperature‐dependent photoluminescence spectra, Fourier transform infrared (FTIR) spectra and time‐resolved FTIR spectra of freshly prepared porous silicon and oxidized porous silicon are examined. The experimental results indicate that there is a gradual transformation of electronic states with ageing in air, because ageing led to the surface oxidation and size reduction of Si nanostructures. This surface variation from hydrogen to oxygen during ageing leads to a red shift of the emissions. A clear quantum‐confinement effect exists for both H‐ and O‐capped porous silicon but the emissions in O‐capped porous silicon show clear polaronic nature. The photoinduced polaron is evidenced by the time‐resolved FTIR results. A reversible H‐detrapping process in silicon wafer occurs with temperature, which influences the conduction of silicon wafer and the photoluminescence of as‐prepared porous silicon due to the carrier density changes. Copyright © 2004 John Wiley & Sons, Ltd.