Luminescence Spectra of β-SiAlON/Pr3+ Under High Hydrostatic Pressure

In this contribution, steady-state and time-resolved photoluminescence spectra of beta-Si5.9Al0.1O0.1N7.9/Pr-0.016(3+) obtained at high hydrostatic pressures up to 260 kbar are presented. At ambient pressure, excitation spectra of the beta-SiAlON/Pr3+ luminescence consist of sharp lines in the spectral region of 20000-22200 cm(-1) related to the H-3(4) -> P-3(0,1,2) transitions and a broad band with two maxima peaking at 30300 and 35700 cm(,)(-1) which are related to the ionization of Pr3+ ions occupying two different crystallographic sites in the beta-SiAlON lattice. In both sites, the luminescence spectra consist of the dominant D-1(2) red emission and P-3(0) blue emission of Pr3+ ions. The intensity of luminescence related to transitions from the P-3(0) state and the respective decay time gradually decreases when the pressure increases. The intensity of emission from the D-1(2) state is independent of the pressure and remains strong over the entire pressure range. Weak dependence of the Pr3+ emission on applied pressure can be related to the covalent and strong Pr-N bonds and specific location of Pr3+ ions occupying empty lattice points in beta-SiAlON.