VUV-vis photoluminescence, X-ray radioluminescence and energy transfer dynamics of Ce³⁺ and Pr³⁺ doped LiCaBO₃

Abstract

A series of LiCaBO 3 :Ce 3+ /Pr 3+ phosphors were prepared by a high-temperature solid state reaction method. A structure refinement for the LiCaBO 3 compound was performed based on powder X-ray diffraction (XRD) data. The energies of the crystal field split excited 5d states of Ce 3+ and Pr 3+ in LiCaBO 3 were determined from synchrotron radiation VUV-UV excitation spectra. Furthermore, the influence of the doping concentration and temperature on the emission properties of Ce 3+ was investigated, and the vacuum referred binding energy (VRBE) scheme for all lanthanide 4f and 5d states in LiCaBO 3 was constructed to estimate the thermal activation energy of Ce 3+ luminescence quenching. The Pr 3+ to Ce 3+ energy transfer (ET) and its influence on luminescence decays of Pr 3+ and Ce 3+ were studied in detail. Finally, the X-ray excited luminescence spectra were measured to evaluate the possible X-ray detection applications.a The refinement reliability can also be judged by the bond valence sum (BVS) calculation. 20,21 The less difference between the BVS value for certain atoms and their oxidation numbers implies the reliability of the refined crystal structure.

Insight into Eu redox and Pr3+ 5d emission in KSrPO4 by VRBE scheme construction

“…In the same site of the same host compound, fluorescence decay of Pr 3+ is usually faster than that of Ce 3+ or Eu 2+ due to its shorter emission wavelength. 11 Therefore Pr 3+ is an important activator in fast decay scintillators. Because the binding energy of outer 5d electrons is highly sensitive to the local coordination environment of the host lattice, it is essential to fully understand the energy and thermal stability of d-f emission of Pr 3+ in various host compounds to find novel Pr 3+ doped scintillation materials.…”

“…This effect also shifts the emission band to the lower energy side in some extent, and meanwhile gives rise to the decrease of relative intensity of 5d 1 -2 F 5/2 emission. 11,29 Therefore, the relative intensity of 5d 1 -2 F 7/2 emission looks like stronger in height-normalized spectra. The ESI Fig.…”

Excitation Wavelength Dependent Luminescence of LuNbO4:Pr3+—Influences of Intervalence Charge Transfer and Host Sensitization

“…We first discuss the possibility of de-excitation pathway through the CR channel. The absence of 3 H 6 ] channel, due to a smaller energy mismatch in the former case. Therefore, CR process is also inefficient for 3 P 0 level in Lu 0.995 Pr 0.005 NbO 4 at RT.…”

VUV/Vis Photoluminescence, Site Occupancy, and Thermal‐Resistance Properties of K4SrSi3O9:Ce3+

“…These phenomena indicate that the thermal quenching of Ce 3+ luminescence occurs at higher temperature. Generally, this thermal quenching process is caused by the increasing nonradiative transition probability at higher temperature, and thermal ionization to the conduction band of electron in 5d states is the predominant quenching pathway . Here, the energy barrier between the bottom of the conduction band and the Ce 3+ 5d 1 state can be simulated by adopting the Mott equation [Eq.…”