Time-resolved spectroscopy of intrinsic luminescence of Y3Ga5O12 and (LaLu)3Lu2Ga3O12 single crystals

Abstract

a b s t r a c tThe nature of intrinsic luminescence of Y 3 Ga 5 O 12 (YGG) and (LaLu) 3 Lu 2 Ga 3 O 12 (LLGG) single crystals grown from a melt was determined. In the case of a YGG single crystal containing Y Ga antisite defects with a concentration of 0.25-0.275 at.% the intrinsic luminescence was considered as a superposition of luminescence of self-trapped excitons (STE), luminescence of excitons localized near antisite defects (LE(AD) centers) and luminescence caused by a recombination of an electron with a hole captured at Y Ga antisite defects. Due to a large (2-3%) concentration of Lu La antisite defects in LLGG single crystals the intrinsic luminescence was a superposition mainly of the LE(AD) center emission and the recombination luminescence of Lu La antisite defects. The energy structure of the mentioned centers in YGG and LGGG hosts was determined from the excitation spectra of their luminescence under excitation by synchrotron radiation in the range of the fundamental absorption edge of these garnets.

Band Gap Modeling of Different Ternary and Quaternary Alumina Garnet Phases Y3(AlxGa1–x)5O12 (YAGG) and Lu3(AlxGa1–x)5O12 (LuAGG). A Semiempirical Approach

“…As for YGG a value of E exc = 5.93 eV, at 8 K, has been reported from which value a band gap of 6.21 eV is obtained, according to eq , in quite good agreement with band gap value reported in the literature for YGG . According to this, by assuming, for YGG, E fa = E g,opt = 5.50 ± 0.05 eV, it is possible to write which can be rearranged as …”

Bandgap Engineering in Yttrium–Aluminum Garnet with Ga Doping

“…The values of the bandgap E g (eV) for the YAGG family were determined using variety of experimental techniques (absorption spectra, optical spectroscopy at LHe, etc. ). ,, We selected one data set and compared it with our results obtained by DFT modeling (Figure ). Several different distributions of Ga over sites were used in calculations: (i) black squares, uniform Ga distribution; (ii) magenta and green, octahedral and tetrahedral Ga occupation, respectively; (iii) blue triangles, Ga distribution from experimental work .…”

Sol–gel synthesis, characterization and study of substitution effects in different gallium-containing garnets

“…Improved physical properties were also observed for differently doped gadolinium scandium gallium garnets (Gd 3 Sc 2 Ga 3 O 12 , GSGG) [41][42][43]. The results reported in several studies [44][45][46][47] indicated that transition metal-or lanthanide-doped lutetium gallium garnets (Lu 3 Ga 5 O 12 , LuGG) are promising new laser materials, and they are expected to be comparable to the most widely used compound, YAG. In addition, these mixed-metal garnets are potential candidates for deep red light-emitting diodes application, which could be used even for plants and vegetables cultivation [48,49].…”