1. Introduction
2. Experimental
3. PL of multilayer
PS film: simulation
4. PL of the inhomogeneous
PS film: Influence of The acetone adsorption
5. Conclusionc
Captures for
the figures
References
Abstract
An impact of inhomogeneities on photoluminescence
of porous silicon is analysed using the numerical simulation
and supported experiment under gas adsorption. Depending
on the excitation wavelength and the condition of measurement
(steady-state or transient mode) the gas adsorption
can result in the quenching or increasing of photoluminescence.
The emission efficiency of the as-prepared porous layers
is shown to decrease at the adsorption of acetone molecules
for each excitation wavelength in 405-546 nm range.
However, if the 546 nm excitation causes small change
of the photoluminescence spectrum during exposition,
the 405 nm excitation quenches the photoluminescence
in the ambient air and increases emission efficiency
in acetone vapours. Effects are discussed with the model
approach of different recombination properties and the
contribution to the photoluminescence incoming of the
upper photooxidised and bottom nanocrystalline layers.
We describe the method of the photoluminescence spectra
fitting in order to determine the gradient profile of
porous layers having depth irregularity of photoluminescence.
Keywords: Porous silicon, Photoluminescence,
Inhomogeneity, Gas adsorption
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