Ba₃Y₂B₆O₁₅:Ce³⁺—A High Symmetry, Narrow-Emitting Blue Phosphor for Wide-Gamut White Lighting

Abstract

The production of white light based on a near-UV LED chip requires incorporating three inorganic phosphors that emit in the blue, green, and red portions of the visible spectrum. Using a near-UV LED has the advantage of generating a light with excellent color quality, but due to the large Stokes' shift between the LED excitation and the multiple phosphor emissions, these devices can suffer from a low overall efficiency. To minimize this inherent energy loss, the three phosphors employed to convert the LED emission must be very efficient, as measured by the internal photoluminescent quantum yield (Φ). In this work, we report the synthesis of a cubic borate, Ba 3 Y 2 B 6 O 15 , which when substituted with Ce 3+ becomes an efficient blue phosphor. This compound can be prepared using a multistep high temperature solid state synthesis with the ensuing photoluminescent measurements revealing a broad excitation band (300−415 nm) making this phosphor compatible with a 365 or 400 nm LED chip. Ba 3 Y 2 B 6 O 15 :Ce 3+ luminesces bright blue (λ em = 446 nm) and is the narrowest Ce 3+ based phosphor reported thus far with a full width at half the maximum of only 70 nm due to its highly symmetric, nearly perfect octahedral rare-earth coordination environment. Moreover, exciting Ba 3 Y 2 B 6 O 15 :Ce 3+ at 365 nm results in a Φ of 84% owing to the dense connectivity of the crystal structure. This combination of a broad excitation spectrum, narrow emission, and high Φ suggest that Ba 3 Y 2 B 6 O 15 :Ce 3+ is an excellent phosphor for incorporation in a three-phosphor, near-UV LED system. Furthermore, these results demonstrate that a highly symmetric and ordered rare-earth environment in combination with a highly connected polyhedral network is a universal design criterion to generate narrow-emitting phosphors.

Strong f‐f Excitation and Bright Red Emission in Cd4Gd1‐xEuxO(BO3)3 (0≤x≤1): Near‐UV LED Pumped Red Phosphor with Low Thermal Quenching

“…Ta bles for cell parameters, agreement factors, atomic coordinates, and selected bond distances for Cd 4…”

“…The new generationo fs olid state lighting is white light emitting diodes( WLEDs), which possesses the apparent advantages of high brightness, low power consumption, long duration, low fabrication cost and environmental friendliness. [1][2][3][4][5][6] The white light can be generated through the combination of the blue emission from an InGaN chip and the yellow emission from the Y 3 Al 5 O 12 :Ce 3 + phosphor,w hich is so-called phosphorconverted (PC) WLEDs. However,i ts uffers from the high correlated colour temperature (CCT % 7750 K) and low colourr endering index (CRI < 80) due to the insufficient red component (> 600 nm), which may limit its performance in,s uch as, general illumination and medical lighting.…”

“…The new generation of solid state lighting is white light emitting diodes (WLEDs), which possesses the apparent advantages of high brightness, low power consumption, long duration, low fabrication cost and environmental friendliness . The white light can be generated through the combination of the blue emission from an InGaN chip and the yellow emission from the Y 3 Al 5 O 12 :Ce 3+ phosphor, which is so‐called phosphor‐converted (PC) WLEDs.…”

The novel borate Lu5Ba6B9O27with a new structure type: synthesis, disordered crystal structure and negative linear thermal expansion

“…The search for novel optical materials, in particular for new red, green and blue (RGB) phosphors suitable for white lightemitting diodes (wLEDs), and their development are of significant interest, because these devices are replacing traditional incandescent and fluorescent light sources and lamps due to their high efficiencies, long operating lifetimes, etc. (Hö ppe, 2009;Pimputkar et al, 2009;Mikami et al, 2011;Hermus et al, 2017;Duke et al, 2018). In the Lu 2 O 3 -BaO-B 2 O 3 phase system, there are four lutetium barium borates known to date: LuBa 3 B 3 O 9 (Ilyukhin & Dzhurinskii, 1994), LuBa 3 B 9 O 18 (Duan et al, 2008), Lu 5 Ba 2 B 5 O 17 (Hermus et al, 2017) and Lu 2 Ba 3 B 6 O 15 (Biryukov et al, 2019).…”

Visualization of UV by Nanopatterned Down‐Shifting Materials Mimicking Human Retinal Cone Cells

“…This relaxation corresponds to the DS process and is followed by the emission of light with a longer wavelength, which is often visible. Owing to this optical characteristic, DS materials have been studied and used in various research and industrial fields, such as UV light‐emitting diodes (LEDs), photovoltaics, photocatalysis, imaging and sensing devices, and anticounterfeit devices …”