•Influence of Ga and La doping on the luminescence of LuAG:Sc and YAG:Sc single crystalline films.•Optical depth and the Stokes shift of ScAl centers luminescence in the LuAG, YAG and ...(Y,Lu)3(Al,Ga)5O12 garnet host.•Comparison of the scintillation properties of Sc doped LuAG, YAG and (Y,Lu)3(Al,Ga)5O12 films.
The paper is dedicated to studying the luminescent and scintillation properties of the single crystalline films of Sc doped multi-component (Y,Lu,La)3(Al,Ga)5O12 garnets grown by the liquid phase epitaxy method.
This work presents the results on creation of novel types of composite scintillators based on Ce3+ doped Gd3Al5-xGaxO12 single crystalline films grown by the LPE method using PbO–B2O3 flux onto ...substrate-scintillators prepared from commercial Gd3Al2.3Ga2.7O12:Ce and Gd3Al2Ga3O12:Ce single crystals. The sets of films with different Ga contents x = 1.75–2.25 and various thicknesses in the 13–150 μm range were grown onto the mentioned substrates. The scintillation properties of the respective epitaxial structures (pulse height spectra, light yield and scintillation decay kinetics) were investigated under excitation by α– (239Pu) particles, β- (90Sr+90Y) particles and γ–quanta (137Cs). The best scintillation properties for simultaneous registration of the mentioned particles and quanta in the mixed radiation fluxes are demonstrated with Gd3Al2.75Ga2.25O12 film/Gd3Al2Ga3O12:Ce substrate epitaxial structure.
•Creation of novel types of composite scintillators based on the Ce3+ doped Gd3Al5-xGaxO12 single crystalline films grown by the LPE method.•Simultaneous registration of ionizing flux (including α-, β-particles and γ-quanta) using composite scintillator.•Determination of the component's separation efficiency of ionized radiation for a composite scintillator using scintillation decay kinetics.
•Comparison of the luminescent properties of the crystals and films of Ce-doped A2SiO5 (A=Lu, Y) orthosilicates.•Formation of Ce3+–Pb2+ pair centers in LSO:Ce and YSO:Ce films grown by LPE method ...from PbO based flux.•High intensity of thermoluminescence of LSO:Ce and YSO:Ce films.
The work is devoted to the comparative analysis of the scintillation and thermoluminescent properties of the undoped and Ce-doped A2SiO5 (A=Lu, Y) orthosilicates, prepared in single crystal form by the Czochralski method and in the form of single crystalline film using the liquid phase epitaxy method. We have found that differences in the methods of material preparation resulted in the significant differences in the scintillation and thermoluminescent properties of undoped and Ce doped YSO and LSO crystals and films. Such differences are caused by the presence or absence of main host defects (first of all, oxygen vacancies and flux related impurities) as emission and trapping centers in YSO and LSO crystals and films.
Single-crystalline films of Lu3Al5O12:Bi, prepared by the liquid phase epitaxy method from the melt-solution based on Bi2O3 flux, have been studied at 4.2-400 K by time-resolved luminescence ...spectroscopy methods. Their emission spectra consist of two types of bands with strongly different characteristics. The ultraviolet emission band consists of two components, arising from the electronic transitions which correspond to the and transitions in a free Bi3+ ion. At low temperatures, mainly the lower-energy component of this emission is observed, having the decay time~10-3 s at T < 100 K and arising from the metastable 3P0 level. At T > 100 K, the higher-energy emission component appears, arising from the thermally populated emitting 3P1 level. The visible emission spectrum consists of two dominant strongly overlapped broad bands with large Stokes shifts. At 4.2 K, their decay times are ~10-5 s and decrease with increasing temperature. Both of the visible emission bands are assumed to have an exciton origin. The lower-energy band is ascribed to an exciton, localized near a single Bi3+ ion. The higher-energy band shows a stronger intensity dependence on the Bi3+ content and is assumed to arise from an exciton localized near a dimer Bi3+ center. The origin and structure of the corresponding excited states is considered and the processes, taking place in the excited states, are discussed.
In this paper we report our follow-up research on the Bi3+ luminescence in orthosilicate compounds, focusing on absorption, luminescent and scintillation properties of YSO:Bi and LSO:Bi SCFs with the ...Bi concentration ranging from 0.05 to 0.18at%. For purpose of this research, single crystalline films (SCF) of Y2SiO5:Bi and Lu2SiO5:Bi have been grown by the LPE method onto YSO and LSO substrates from the melt-solution based on Bi2O3 flux.
•YSO:Bi and LSO:Bi films have been grown by liquid phase epitaxy.•Bi3+ absorption and luminescence depends on Bi concentration.•Scintillation properties of YSO:Bi and LSO:Bi films have been studied.
The absorption, cathodoluminescence, excitation spectra of photoluminescence (PL) and PL decay kinetics were studied at 300K for the double Bi3+–Ce3+-doped and separately Bi3+- and Ce3+-doped ...Y3Al5O12 (YAG) and Lu3Al5O12 (LuAG) single crystalline film phosphors grown by liquid phase epitaxy method. Emission bands in the UV range arising from the intrinsic radiative transitions of Bi3+-based centers, and emission bands in the visible range related to the luminescence of excitons localized around Bi-based centers, were identified in both Bi–Ce and Bi-doped YAG and LuAG SCF. Energy transfers from the host lattice to Bi3+ and Ce3+ ions and from Bi3+ to Ce3+ ions were investigated. Competition between Bi3+ and Ce3+ ions in the energy transfer from the YAG and LuAG hosts was evidenced. A strong decrease of intensity of the Ce3+ luminescence both in YAG:Ce and LuAG:Ce SCF phosphors, grown from a Bi2O3 flux, is observed due to the quenching influence of Bi3+ flux related impurity. Due to overlap of the visible emission band of Bi3+ centers with the absorption band of Ce3+ ions peaking at around 450–460nm, an effective energy transfer from Bi3+ ions to Ce3+ ions takes place, resulting in the appearance of a slower component in the Ce3+ luminescence decay kinetics.
► Bi- and Ce-doped single crystalline film phosphor grown by liquid phase epitaxy method from Bi2O3 flux. ► Energy transfer from Bi3+ to Ce3+ ions. ► Strong quenching of the Ce3+ luminescence by the Bi3+ co-dopant.
Absorption, cathodoluminescence, excitation spectra of photoluminescence (PL) and PL decay kinetics were studied at 300K for the double doped with Bi3+–Pr3+ and separately doped with Bi3+ and Pr3+ ...Lu3Al5O12 (LuAG) and Y3Al5O12 (YAG) single crystalline film (SCF) phosphors grown by the liquid phase epitaxy method. The emission bands in the UV range arising from the intrinsic radiative transitions of Bi3+ based centers, and emission bands in the visible range, related to the luminescence of excitons localized around Bi3+ based centers, were identified both in Bi–Pr and Bi-doped LuAG and YAG SCFs. The energy transfer processes from the host lattice simultaneously to Bi3+ and Pr3+ ions and from Bi3+ to Pr3+ ions were investigated. Competition between Pr3+ and Bi3+ ions in the energy transfer processes from the LuAG and YAG hosts was evidenced. The strong decrease of the intensity of Pr3+ luminescence both in LuAG:Pr and YAG:Pr SCFs phosphors, grown from Bi2O3 flux, is observed due to the quenching influence of Bi3+ flux related impurity. Due to overlap of the UV emission band of Bi3+ centers with the f–d absorption bands of Pr3+ ions in the UV range and the luminescence of excitons localized around Bi ions with the f–f absorption bands of Pr3+ ions in the visible range, an effective energy transfer from Bi3+ ions to Pr3+ ions takes place in LuAG:Bi,Pr and YAG:Bi,Pr SCFs, resulting in the appearance of slower component in the decay kinetics of the Pr3+ d–f luminescence.
•Bi and Pr doped film phosphor grown by liquid phase epitaxy method.•Energy transfer from Bi3+ to Pr3+ ions.•Strong quenching of the Pr3+ luminescence by Bi3+ co-dopant.
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