Evolution of photoluminescence of porous silicon under light exposure
Journal
Journal of Applied Physics
Journal Volume
77
Journal Issue
10
Pages
5365-5368
Date Issued
1995
Author(s)
Abstract
Time evolution of the photoluminescence spectra of low current density electrochemically etched porous silicon are studied. When the sample is exposed to light illumination in atmosphere, the luminescence intensity decays initially. However, after a short period of degradation, it starts to enhance gradually. The profiles of the photoluminescence spectra including peak position and line width are very different for the decay and enhancement processes. When the sample is illuminated in vacuum, only a decay process is observed. Infrared spectrum shows that the hydrogen related bonding in the as-anodized sample is replaced by the oxygen related termination. A quantum confinement model together with the activity of nonradiative recombination centers is proposed to explain our observations. After oxidation under light exposure, the intensity of the photoluminescence is strong and stable. Thus, our study also provides a room temperature oxidation method for producing strong and stable luminescent porous silicon.
Type
journal article