Three types of luminescence centers are observed in phosphorus
containing oxides: phosphosilicate glasses and α-quartz
silicon dioxide crystal doped with phosphorus. Corresponding
bands are situated in UV, visible and yellow–red ranges of spectra.
UV luminescence is provided by center existing in as received
materials and ascribed to the states related to PO4
3− ion based on
similarity of UV luminescence with STE luminescence in ScPO4
crystal. Yellow luminescence belongs to radiation induced transient
centers connected with presence of phosphorus, but structure
of this center is not yet clear. The same unknown structure is
for red luminescence center, also belonging to presence of phosphorus.
These centers participate in electron hole recombination
process in different ways. The band at 600 nm could be excited in
over barrier recombination whereas 740 in tunneling recombination.
Annealing of crystal sample at 550 °C reconstructs phosphorus
position. It diminishes UV luminescence, however yellow
luminescence completely disappeared. ArF irradiation induces
non-bridging oxygen luminescence center in crystalline lattice
after treatment to 550 °C. This center corresponds to phosphorus
which position could be diminished in quantity by heat treatment
to 660 °C. NBO could not be created by irradiation after treatment
to 660 °C. Heating at 450–500 °C of treated samples partly recover
ability to create yellow luminescence centers. Evidently, water,
existing in the sample, changes it position and restoring in some
way initial defect's precursors.