Color Tunable Emission of Y₃Al₅O₁₂:Ce³⁺and Sm³⁺‐Doped Zinc–Germanate–Tellurite Glass Nanocomposite Powders and Coatings for Light‐Emitting Diodes Applications

Abstract

A series of nanocomposite (NC) powders and coatings of ZnO–GeO2–TeO2:xSm3+ glass and Y3Al5O12:Ce3+ nanoparticles (YAG:Ce) are fabricated. Samarium ions concentration of the glass phosphor is varied with x values of 0.3, 1.0, 3.0, and 5.0 mol%. The powder batches are prepared with a 95/5 mass ratio of glass/YAG:Ce and uniaxially pressed to obtain powder pellets that are heat‐treated at 350 °C. Morphology and structural characterization are conducted through X‐ray diffraction analysis, scanning electron microscopy, and Raman spectroscopy. The photoluminescence properties of NCs are investigated under different wavelengths of 340, 403, and 460 nm, showing a global emission tonality in the reddish‐orange and yellowish‐green region according to the estimated CIE 1931 chromaticity coordinates. Also, NC coatings soda–lime glass slides are fabricated, and their photoluminescence is characterized using an UV light‐emitting chip (≈365 nm) and a blue light‐emitting chip (≈460 nm). The global emission under UV and blue light from the light‐emitting diode (LED) chips of the NC coatings shows a color tunability in the warm white light and yellowish‐green region.

Microstructures and Luminescent Properties of Sm3+‐Doped KSr2Nb5O15 Prepared by Molten Salt Synthesis Method

“…The correlated color temperatures (CCT) can be calculated based on the CIE chromaticity coordinates using McCamy's approximate. [44] Figure 8b shows the partial energy-level schematic diagram of Sm 3þ in KSr 2-3x/2 Sm x Nb 5 O 15 phosphors. Possible transition processes of electrons could be described as: the electrons of Sm 3þ ions were initially excited to higher excited state 6 P 3/2 .…”

First-Principles Analysis of the Effects of Covalency and Ionicity on the 4f–5d Transition Energy of Ce3+ in Garnet-Type Oxides

“…The common phosphor materials used are oxides, 5 garnets, 6 silicates, 7 sulfides, 8 and nitrides 9 doped with various transition metals [10][11][12][13] or rare-earth elements. [14][15][16][17] The general chemical formula of the garnet-type crystal host is denoted as (A) 3 [B] 2 <C 3 >O 12 , where the (A) 24c site bonds to oxygen to form [AO 8 ] dodecahedrons. A large lanthanide ion (Ln 3+ ) often occupies this site.…”