Luminescence of Phosphorus Containing Oxide Materials: Crystalline SiO2-P and 3P2O5·7SiO2; CaO·P2O5; SrO·P2O5 glasses

A. N.Trukhin, K. Smits, J. Jansons, D. Berzins, G. Chikvaidze,

ABSTRACT. Luminescence of phosphate glasses such as CaO·P2O5 and SrO·P2O5 is compared with that of phosphorus doped
crystalline -quartz and phosphosilicate glass with content 3P2O5·7SiO2. Water & OH groups are found by IR spectra in these
materials. The spectrum of luminescence contains many bands in the range 1.5 – 5.5 eV. The luminescence bands in UV range at
4.5- 5 eV are similar in those materials. Decay duration in exponential approximation manifests a time constant about 37 ns. Also
a component in μs range was detected. PL band of μs component is shifted to low energy with respect to that of ~37 ns
component. This shift is about 0.6 eV. It is explained as singlet-triplet splitting of excited state. Below 14 K increase of
luminescence kinetics duration in μs range was observed and it was ascribed to zero magnetic field splitting of triplet excited
state of the center. Yellow-red luminescence was induced by irradiation in phosphorus doped crystalline -quartz,
phosphosilicate glasses. The yellowl uminescence contains two bands at 600 and 740 nm. Their decay is similar under 193 nm
laser and may be fitted with the first order fractal kinetics or stretched exponent. Thermally stimulated luminescence contains
only band at 600 nm. The 248 nm laser excites luminescence at 740 nm according to intra center process with decay time
constant about 4 ms at 9 K. Both type of luminescence UV and yellow were ascribed to different defects containing phosphorus.
P-doped α-quartz sample heated to 550 co become opalescent. Ir spectra related to water & OH groups are changed.
Photoluminescence intensity of all three bands, UV (250 nm), yellow (600 nm) and red (740 nm) strongly diminished and
disappeared after heating to 660 Co. Radiation induced red luminescence of non-bridging oxygen luminescence center (NBO)
appeared in crystal after heat treatment. We had observed a crystalline version of this center (l. Skuja et al, Nuclear Instruments
and Methods in Physics Research B 286,159–168 (2012)). Effect of heat treatment explained as sedimentation of phosphorus in
some state. Keeping of treated sample at 450-500 Co leads to partial revival of ability to create yellow luminescence center
under irradiation.

AIP Conf. Proc. 1624, 154-166 (2014);

doi: 10.1063/1.4900472

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