Luminescence of Ce3+ at two different sites in α-Sr2P2O7 under vacuum ultraviolet-UV and x-ray excitation

Abstract

A series of Ce 3+ doped ␣-Sr 2−2x Ce x Na x P 2 O 7 phosphor compounds has been prepared using a high-temperature solid-state reaction technique. The luminescence properties under vacuum ultraviolet-UV and x-ray excitation were studied. Luminescence spectra reveal three UV-emitting peaks at about 310, 330, and 350 nm from which we conclude that Ce 3+ occupies two distinct sites in ␣-Sr 2 P 2 O 7 . The influences of the doping concentration, the temperature, and the excitation wavelength on the luminescence of Ce 3+ at the Ce͑I͒ and Ce͑II͒ sites together with the decay characteristics are discussed. The light yield under x-ray excitation is found to be around 10 000 photons/MeV.

Luminescence of Li6Gd(BO3)3 crystals upon ultraviolet and inner-shell excitations

“…The splitting depends on many factors, and within a small range the splitting width varies depending on the temperature and excitation conditions. Table 1 shows that the values of splitting obtained in our measurements are quite close to the expected value of 0.25 eV [42].…”

Cathodoluminescence kinetics of Li6GdB3O9 crystals

“…The splitting depends on many factors and varies from crystal to crystal. Its mean value is about 0.25 eV [45]. This is quit consistent with the observed luminescence spectra within the energy range of 2.5-3.4 eV, Fig.…”

“…It is known [45] that the radiative 5d-4f transitions in the luminescence spectra of Ce 3 þ ions are usually manifested in the form of doublet of broad, partially overlapped emission bands. These emission bands are due to radiative transitions from the lowest relaxed 5d-excited state to the ground 4f state, split by the spin-orbit interaction on the two levels of 2 F 5=2 and 2 F 7=2 .…”

Luminescence and energy transfer of emission tunable phosphors YBa3B9O18:Ce3+, Tb3+

“…As a sensitizer, Ce 3+ often shows intense 4f5d absorption band in ultraviolet (UV) region in many oxide hosts and enhance the light yield of the activator through the energy transfer (ET) process from Ce 3+ to activator under UV excitation, which is of great value to improve the luminescence efficiency of phosphors for white light-emitting diodes w-LEDs application. Furthermore, the 5d-4f transitions of Ce 3+ ion can show visible light emission in a suitable host lattice [5,6]. So, the emission color of phosphor doped with Ce 3+ ions can also be tuned in certain range by co-doping with activator ion in term of different emission intensity ratio of Ce 3+ to activator.…”