2. Experimental
The porous layers were prepared on phosphorus doped,
(100) oriented silicon substrates of 4.5 W.cm resistivity
and 350 mm thickness. The growing of the porous layers
was provided by the anodization in the solution of 48
w.%HF: C2H6O (1:2) with two regimes:
at the constant current density of 20 mA/cm2
for 15 min and at discrete subsequence steps of the
current, namely, 40, 32, 24, 16 and 8 mA/cm2
for 3 min of each current value. The selected technological
regimes allow to form the material with the porosity
within 60 - 70 % [16]. The rate of PS layer growth is
about 6-10 nm per second. In this case, the thickness
of each layers formed by the second regime is estimated
to be equal 1.1-1.8 mm. The PL of PS has been excited
by the DRSh-250-2 mercury lamp through the system of
the optical filters with a singular selected emission
at 365, 405, 436, 546 or 578 nm. The PL spectra of the
as-prepared PS films were measured in transient and
steady-state modes in two atmospheres- ambient air and
saturated acetone vapours. The steady state mode is
achieved by the stabilization of the PL intensity when
the patterns are excited by 405 nm for 30 min, then
by 436 nm for 5 min and 546 nm for 5 min. Such a treatment
evokes the 1.8 time reduction of the PL yield for 10
min and then PL exhibits no change during measurement
neither in ambient atmosphere nor in acetone vapours.
abstract
1. Introduction
2. Experimental
3. PL of multilayer PS film:
simulation
4. PL of the inhomogeneous PS
film: Influence of The acetone adsorption
5. Conclusions
Captures for the figures
References
V.A.Skryshevsky
Radiophysics Department, Kiev Shevchenko
University,
64 Vladimirskaya, 01033, Kiev, Ukraine, fax.+380-44-2656744,
e-mail: skrysh@uninet.kiev.ua
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