Disorder response of 3d3 ions zero-phonon lines in the luminescence spectra of Yttrium-Aluminum-Gallium garnet solid solution ceramics

Broadband near-infrared (NIR) emission realized by the crystal-field engineering of Y3−xCaxAl5−xSixO12:Cr3+(x= 0–2.0) garnet phosphors

“…26 Y 3 Al 5Àx Ga x O 12 :Cr has a broadband emission covering the spectral range of 620-800 nm. 24 These investigations demonstrate the feasibility of the substitution strategy to realize broadband NIR emissions of Cr 3+ in garnets. On the other hand, in this work, direct regulation is performed only in the dodecahedron and/or octahedron sites (i.e., the B sites in A 3 B 2 C 3 O 12 that Cr 3+ prefers to occupy); 27 the resulting structural distortion thus has a very limited effect on the broadening of the emission band.…”

“…Single-or double-substitution of cations in the garnet structure would cause structural distortion and decrease the crystal symmetry, which changes the crystal field strength and finally regulates the luminescence of Cr 3+ . 23,24 Accordingly, many efforts have been made to search for NIR phosphors in the garnet system. For example, Ca 2 LuZr 2 Al 3 O 12 :Cr exhibits a broad emission band with FWHM of 117 nm (from 650 to 870 nm) and has an internal quantum efficiency (IQE) of 69.1%.…”