Role of Dy³⁺ → Sm³⁺ energy transfer in the tuning of warm to cold white light emission in Dy³⁺/Sm³⁺ co-doped Lu₃Ga₅O₁₂ nano-garnets

Abstract

Nano-crystalline lutetium gallium garnets co-doped with Dy3+ and Sm3+ ions have been synthesized via a sol–gel method and their structural, morphological and luminescence properties have been characterized.

High Thermal Stability Apatite Phosphors Ca2La8(SiO4)6O2:Dy3+/Sm3+ for White Light Emission: Synthesis, Structure, Luminescence Properties and Energy Transfer

“…(6), it is found that the critical distance R C equals 14.809 Å in CLSO:0.20Dy 3+ /0.20Sm 3+ phosphors. And similar values are found in other systems 27,30 . Therefore, when distance between rare earth ions R < 6 Å, there exchange interaction dominants in energy transfer processes 31 while quadrupole-quadrupole interaction contributes to those processes when 6 Å < R < 14.809 Å in CLSO:0.20Dy 3+ /0.20Sm 3+ phosphor.…”

“…5(B). It can be found that when n value takes 10, the value of linear fitting coefficient R 2 is biggest and linear behavior is best, therefore it reveals Dy 3+ → Sm 3+ energy transfer via quadrupole-quadrupole interaction mechanism, which is consistent with others’ previous investigation 27 .…”

“…These CIE chromaticity coordinates were calculated based on their PL spectrum, and the results are shown on Table 2 with CCT. The correlated color temperature can be estimated by following McCamy empirical formula 27,33 :where n equals (x − x e )/(y − y e ), and the chromaticity epicenter (x e , y e ) is (0.3320,0.1858). All of CCT of CLSO apatite phosphors are over 5000 K, which is boundary temperature, CCT of white light emission less than 5000 K named warn white light used for household lighting or appliances and conversely clod white light more suitable for commercial application for lighting purposes.…”

Garnet-Type Nanophosphors for White LED Lighting

“…At the nanoscale, the literature is scarcer and mainly reports nanophosphors doped with trivalent lanthanide ions (Gd 3+ , Eu 3+ , Sm 3+ , Dy 3+ , Tb 3+ ), exhibiting electronic intraconfigurational transitions in the red range. Such ions are incorporated as dopant or co-dopant in the garnet-type nanophosphors and provide red emission components (Figure 2; Potdevin et al, 2005;Li and Shen, 2012;Yan et al, 2012;Haritha et al, 2014;Pamuluri et al, 2018;Ali and Khedr, 2019).…”

Impact of Tb3+ ion concentration on the morphology, structure and photoluminescence of Gd2O2SO4:Tb3+ phosphor obtained using thermal decomposition of sulfate hydrate

“…Rare earth oxides (RE 2 O 3 ), garnets (RE 3 A 2 B 3 O 12 , in which A and B are tetrahedral and octahedral coordinates in metal sites, respectively), oxysulfides (RE 2 O 2 S) and oxysulfates (RE 2 O 2 SO 4 ) are excellent host materials based on their optical properties. [9][10][11][12][13][14][15][16][17][18][19][20] In particular, gadolinium oxysulfate/oxysulfide (Gd 2 O 2 SO 4 /Gd 2 O 2 S) doped with Tb 3+ and Eu 3+ have revealed outstanding optical properties. Ln 2 O 2 S hosts have been used as ligand matrices for ligand to metal charge transfer (LMCT) and 4f states of lanthanides have contributed to optical processes.…”