Facile Atmospheric Pressure Synthesis of High Thermal Stability and Narrow-Band Red-Emitting SrLiAl₃N₄:Eu²⁺ Phosphor for High Color Rendering Index White Light-Emitting Diodes

Abstract

Red phosphors (e.g., SrLiAl3N4:Eu(2+)) with high thermal stability and narrow-band properties are urgently explored to meet the next-generation high-power white light-emitting diodes (LEDs). However, to date, synthesis of such phosphors remains an arduous task. Herein, we report, for the first time, a facile method to synthesize SrLiAl3N4:Eu(2+) through Sr3N2, Li3N, Al, and EuN under atmospheric pressure. The as-synthesized narrow-band red-emitting phosphor exhibits excellent thermal stability, including small chromaticity shift and low thermal quenching. Intriguingly, the title phosphor shows an anomalous increase in theoretical lumen equivalent with the increase of temperature as a result of blue shift and band broadening of the emission band, which is crucial for high-power white LEDs. Utilizing the title phosphor, commercial YAG:Ce(3+), and InGaN-based blue LED chip, a proof-of-concept warm white LEDs with a color rendering index (CRI) of 91.1 and R9 = 68 is achieved. Therefore, our results highlight that this method, which is based on atmospheric pressure synthesis, may open a new means to explore narrow-band-emitting nitride phosphor. In addition, the underlying requirements to design Eu(2+)-doped narrow-band-emitting phosphors were also summarized.

Controlling of Structural Ordering and Rigidity of β-SiAlON:Eu through Chemical Cosubstitution to Approach Narrow-Band-Emission for Light-Emitting Diodes Application

“…. 41,42 When Al→Si and O→N substitutions simultaneously occur in β-Si3N4, a structure of β-SiAlON is obtained, similar to that of β-Si3N4. As z increases, such substitution would inevitably cause an increasing degree of structural disorder in the framework of β-Si3N4, and consequently result in a decrease in the force constant of the Si-N bond.…”

The Enhanced Red Emission and Improved Thermal Stability of CaAlSiN3:Eu2+ Phosphors by Using Nano-EuB6 as Raw Material

“…Currently, several red emitting phosphors attract much attention and are pervasively studied due to the property of effectively enhancing the color rendition, such as M 2 Si 5 N 8 :Eu 2+ (M = Ca, Ba, Sr) [8,9,10,11], SrLiAl 3 N 4 :Eu 2+ [12,13,14,15] and CASN:Eu 2+ [16,17,18,19]. Among the above red phosphors, the emission of Eu 2+ in CaAlSiN 3 host locates in deep red region and possesses the advantages of good thermal stability, reliability and high quantum efficiency, which make it superior to others.…”

Tunable photoluminescence of apatite phosphor Ca5.95−xSrxLa4(SiO4)2(PO4)4O2:0.05Eu2+ and its application in light‐emitting diodes

“…The XRD patterns of Ca 5.95− x Sr x La 4 (SiO 4 ) 2 (PO 4 ) 4 O 2 :0.05Eu 2+ ( x = 0, 1, 2, 3, 4, 5, 5.95) and diffraction data of Ca 2 La 8 (SiO 4 ) 6 O 2 (JCPDF 29‐0337) are presented in Figure , respectively. As shown in Figure , the diffraction peaks match the standard peaks well, demonstrating that the series of single‐phase apatite phosphors has been synthesized successfully . Meanwhile, the substitution of the Ca 2+ ion by the Sr 2+ ion and the introduction of the Eu 2+ ion does not cause any phase transition or impurities.…”