Abstract:
We report the effect of high-temperature treatment on the structure and photoluminescence
of zinc selenite nanocrystals (ZnSeO3
) deposited into SiO2/Si track templates. The templates were
formed via irradiation with Xe ions (200 MeV, 108
ions/cm2
) followed by etching in HF solution.
ZnSeO3 nanocrystals were obtained via chemical deposition from the aqueous solution of ZnCl2 and
SeO2 as Zn-, Se- and O-precursors. To estimate the thermal stability of the deposited precipitates, heat
treatment was carried out at 800 and 1000 ◦C for 60 min in a vacuum environment. Scanning electron
microscopy (SEM), X-ray diffractometry (XRD), photoluminescence (PL) spectroscopy, and electrical
measurements were used for the characterization of ZnSeO3/SiO2nanoporous/Si nanocomposites.
Thermal treatment of the synthesized nanocomposites resulted in structural transformations with
the formation of ZnSe and ZnO phases while the content of the ZnSeO3 phase decreased. For the
as-deposited and annealed precipitates, an emission in the range of (400 to 600) nm was observed.
PL spectra were approximated by four Gaussian curves with maxima at ~550 nm (2.2 eV), 488 nm
(2.54 eV), ~440 nm (2.82 eV), and 410 nm (3.03 eV). Annealing resulted in a decrease in PL intensity that
was possibly due to the weight loss of the deposited substance during high-temperature treatment.
The redistribution of maxima intensities after annealing was also observed with an increase in blue
and violet emissions. The origin of the observed PL is discussed. The I–V curve analysis revealed an
electronic type of conductivity for the ZnSeO3
(NCs)/SiO2nanoporous/Si structure. The values of the
specific conductivity were calculated within the percolation model. The sample annealed at 800 ◦C
showed the highest specific conductivity of 8.5 × 10−6 Ohm−1
·cm−1.
