Crystal structure and luminescence properties of a novel non-rare-earth activated blue-emitting garnet phosphor Ca4ZrGe3O12: Bi3+ for n-UV pumped light-emitting diodes

Tuning Emission from Greenish to Blue via Chemical Composition Modulation in Solid Solutions (Sr1–yCay)2Sb2O7:Bi3+ under near-UV Light Excitation

“…In the beginning, the intensity grows gradually with increasing x, with a maximum at x = 0.03, and then constantly decays if further increasing x. Undoubtedly, this phenomenon is a result of the concentration quenching effect, and the concrete mechanism might be determined using critical distance R c , which was calculated by Blasse's equation: 26,27…”

“…In the beginning, the intensity grows gradually with increasing x , with a maximum at x = 0.03, and then constantly decays if further increasing x . Undoubtedly, this phenomenon is a result of the concentration quenching effect, and the concrete mechanism might be determined using critical distance R c , which was calculated by Blasse’s equation: , Herein, the formula number N is 4, the volume V is 594.29 Å 3 , and the critical concentration of Bi 3+ ( X c ) is 0.03. The R c in Sr 2 Sb 2 O 7 : x Bi 3+ is 21.15 Å, which is far beyond 5 Å.…”

Giant Photoluminescence Improvement and Controllable Emission Adjustment in Bi3+-Activated Ca4ZrGe3O12 Phosphors for High-Quality White Light-Emitting Diodes

“…The XRD patterns of as-prepared CZGO: x Bi 3+ ( x = 0–3.0%) have been provided in Figure S1a. The diffraction peaks of all samples match well with the standard CZGO . No obvious impurities appear, proving the formation of pure phase.…”

Tunable dual‐mode emission with excellent thermal stability in Ca4ZrGe3O12:Eu phosphors prepared in air for NUV‐LEDs

“…The 24c, 16a, 24d, and 96h Wyckoff sites are occupied by Ca 2+ , Zr 4+ , Ge 4+ , and O, respectively. The [CaO 8 ] dodecahedra are distorted and have two types of Ca–O bond with a length of one bond being 2.4382 Å and that of the other being 2.5649 Å, while [Ca/ZrO 6 ] octahedrons and [GeO 4 ] tetrahedrons are regular, Ca/Zr–O and Ge–O bond lengths are 2.1938 and 1.7632 Å, respectively . Due to the similar effective ionic radius (Ca 2+ , 1.00 Å; Eu 2+ , 1.17 Å; and Eu 3+ , 0.947 Å), the Eu dopants prefer to replace Ca 2+ sites.…”

“…Rare‐earth ions‐doped germanate compounds with garnet structure have been reported as a promising luminescent phosphors with good performance . Ca 4 ZrGe 3 O 12 (CZGO), as a kind of garnet compounds, was selected as the host in this work. The structure and optical properties of CZGO:Eu were discussed systematically via XRD, luminescent spectra, decay curves, and temperature‐dependent emission.…”