Red-emitting YAG: Ce, Mn transparent ceramics for warm WLEDs application

Abstract

A series of YAG:Ce,Mn transparent ceramics were prepared via a solid-state reaction-vacuum sintering method. The effects of various Mn 2+-Si 4+ pair doping levels on the structure, transmittance, and luminescence properties were systematically investigated. These transparent ceramics have average grain sizes of 10-16 μm, clean grain boundaries, and excellent transmittance up to 83.4% at 800 nm. Under the excitation of 460 nm, three obvious emission peaks appear at 533, 590, and 745 nm, which can be assigned to the transition 5d→4f of Ce 3+ and 4 T 1 → 6 A 1 of Mn 2+. Thus, the Mn 2+-Si 4+ pairs can effectively modulate the emission spectrum by compensating broad orange-red and red spectrum component to yield high quality warm white light. After the optimized YAG:Ce,Mn transparent ceramic packaged with blue light-emitting diode (LED) chips, correlated color temperature (CCT) as low as 3723 K and luminous efficiency (LE) as high as 96.54 lm/W were achieved, implying a very promising candidate for application in white light-emitting diodes (WLEDs) industry.

Crystal structure, luminescence properties and application performance of color tuning Y2Mg2Al2Si2O12:Ce3+,Mn2+ phosphors for warm white light-emitting diodes

“…Then, the 4 T 1 -6 A 1 transition of Mn 2+ results in an orange-red emission. 38,39 3.5 CIE of YMAS:Ce 3+ and YMAS:Ce 3+ ,Mn 2+…”

Composition and structure design of three-layered composite phosphors for high color rendering chip-on-board light-emitting diode devices

“…or partial substitute of Y 3+ by different ions (Gd 3+ , etc.) in YAG:Ce to add red spectral components in its spectrum, but usually with a sacrifice in luminous efficacy [15][16][17][18][19]. Alternatively, composite phosphor ceramics consisting of both red-and yellow-emitting phosphors are expected to realize high color rendering lighting.…”

Crystallization kinetics of Al2O3-26mol%Y2O3 glass and full crystallized transparent Y3Al5O12-based nanoceramic

“…Yttrium aluminum garnet Y 3 Al 5 O 12 (YAG) transparent ceramics have become a competitive substitute of YAG single crystals as host materials for solid state lasers, phosphors, and scintillators due to the advantages of the elaboration process (time-saving production period, low cost) and product characteristics (geometric versatility, relatively swift scalable manufacturing, and doping flexibility) [1][2][3][4][5][6]. In the last decades, various sintering synthetic approaches have been employed to synthesize the YAG transparent ceramics, such as spark plasma sintering [7,8], vacuum sintering [9], and hot isostatic pressing sintering [10].…”