Comparison of luminescence between Eu2+-activated Na2CaPO4F and NaCaPO4 green-emitting phosphors for pc-wLEDs. Issue 7 (1st April 2023)

• Record Type: Journal Article
• Authors: Zhao, Shujuan; Liao, Shuzhen; Qiu, Zhongxian; Lian, Shixun; Zhang, Jilin
• Is Part Of: Ceramics international. Volume 49:Issue 7(2023)
• Page Start: 11285
• Page End: 11292
• Publication Date: 2023-04-01
• Subjects: Phosphor -- A. powders: solid state reaction -- C. Optical properties -- D. Phosphate; pc-wLEDs phosphor-converted white light-emitting diodes -- CRI color-rendering index -- QE quantum efficiency -- XRD X-ray powder diffraction -- PLE excitation -- PL emission -- GSAS general structure analysis system -- DR diffuse reflectance -- FWHM full-width at half maximum -- CIE International Commission on Illumination -- IQE internal QE -- EQE external QE -- EL electroluminescence -- LE luminescence efficacy -- SEM Scanning electron microscope -- EDS energy dispersive spectroscopy; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2022.11.327
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Full-spectrum lighting is benefit to human eyes' healthy and attracts increasing attention. Therefore, phosphor-converted white light-emitting diodes (pc-wLEDs) for illumination need phosphors with broadband emission, especially those covering the cyan-emitting region. This work compares the structure and luminescent properties of NaCaPO4 :Eu 2+ and Na2 CaPO4 F:Eu 2+ phosphors. Although both phosphors exhibit a broad emission band peaking at 505 nm, Na2 CaPO4 F:Eu 2+ has a broader band than NaCaPO4 :Eu 2+ . This is because Na2 CaPO4 F has more crystallographic sites for Eu 2+ ion. Furthermore, the phosphors with NaCaPO4 phase have better thermal stability and higher internal quantum efficiency than those with Na2 CaPO4 F phase. A smaller Stokes shift and a larger band gap are responsible for the better thermal stability of NaCaPO4 :Eu 2+ . The performance of the pc-wLEDs based on these two types of phosphors suggests their potential as green-emitting component to achieve full-spectrum illumination.