Composite Detectors Based on Single-Crystalline Films and Single Crystals of Garnet Compounds

Abstract

This manuscript summarizes recent results on the development of composite luminescent materials based on the single-crystalline films and single crystals of simple and mixed garnet compounds obtained by the liquid-phase epitaxy growth method. Such composite materials can be applied as scintillating and thermoluminescent (TL) detectors for radiation monitoring of mixed ionization fluxes, as well as scintillation screens in the microimaging techniques. The film and crystal parts of composite detectors were fabricated from efficient scintillation/TL materials based on Ce3+-, Pr3+-, and Sc3+-doped Lu3Al5O12 garnets, as well as Ce3+-doped Gd3−xAxAl5−yGayO12 mixed garnets, where A = Lu or Tb; x = 0–1; y = 2–3 with significantly different scintillation decay or positions of the main peaks in their TL glow curves. This work also summarizes the results of optical study of films, crystals, and epitaxial structures of these garnet compounds using absorption, cathodoluminescence, and photoluminescence. The scintillation and TL properties of the developed materials under α- and β-particles and γ-quanta excitations were studied as well. The most efficient variants of the composite scintillation and TL detectors for monitoring of composition of mixed beams of ionizing radiation were selected based on the results of this complex study.

Novel composite color converters based on Tb1.5Gd1.5Al5O12:Ce single crystalline films and Y3Al5O12:Ce crystal substrates

“…The garnet-forming components were weighed in an appropriate ratio together with PbO and B 2 O 3 flux. 30,31 Throughout the film growth process, the substrate horizontally attached to a platinum holder was rotating at 60-80 rpm in the forming melt with growth temperature T g in the 950-1025 °C range. Under described conditions, the growth rate was in the f s = 0.35-1.6 μm min −1 range.…”

“…29 The following stage in developing the composite color converters is connected with the application of the SCF converters based on the mixed Tb 3+ and Gd 3+ containing garnet compounds. 30,31 Namely, the combination of the emission coming from Ce 3+ doped Tb 3−x Gd x Al 5 O 12 SCFs and the YAG:Ce crystal part of such a composite color converter under blue or UV LED excitation allows obtaining a wide spectrum of WLEDs similar to the spectrum of natural white light with enhanced luminous efficacy in comparison with standard photoconverters.…”

“…Recently the luminescence and scintillation properties of the Tb 3− x Gd x Al 5 O 12 SCFs, grown via LPE onto undoped YAG substrates, were investigated and published in ref. 30 and 31. However, the possibility of application of such films as WLED phosphor-converters strongly needs experimental confirmation.…”

Development of the Composite Thermoluminescent Detectors Based on the Single Crystalline Films and Crystals of Perovskite Compounds

“…In addition to the so-called composite scintillators of the “phoswich-type” (phosphor sandwich) , for the simultaneous registration of the components of mixed ionization fluxes (for example α-and β- particles and X rays or γ-quanta), the composite TL detectors can be also successfully applied [ 11 , 12 , 13 ]. The development of such detectors of both types is now an actual subject of luminescent material engineering [ 12 , 13 , 14 , 15 ].…”

“…The development of such detectors of both types is now an actual subject of luminescent material engineering [ 12 , 13 , 14 , 15 ]. The basis for such engineering of composite detectors is the latest subject in the development of bulk single crystal (SC) and single crystalline film (SCF) scintillators and TL materials as well as the technologies of their production using the Czochralski and other melt growth methods and the liquid phase epitaxy (LPE) growth techniques, respectively [ 11 , 12 , 13 , 14 , 15 ].…”