Enhanced thermal quenching characteristic via carbon doping in red‐emitting CaAlSiN3:Eu2+ phosphors. Issue 12 (4th June 2019)

• Record Type: Journal Article
• Authors: Tian, Junhang; Zhuang, Weidong; Liu, Ronghui; Wang, Ligen; Liu, Yuanhong; Yan, Chunpei; Chen, Guantong; Xu, Huibing; Chen, Mingyue; Jiang, Ze; Zhang, Xia
• Is Part Of: Journal of the American Ceramic Society. Volume 102:Issue 12(2019)
• Page Start: 7336
• Page End: 7346
• Publication Date: 2019-06-04
• Subjects: blue‐shifted emission -- carbon -- nitride phosphor -- thermal quenching; Ceramics -- Periodicals; 620.1405
• DOI: 10.1111/jace.16601
• Languages: English
• ISSNs: 0002-7820

Abstract

Abstract: Enhancing thermal quenching characteristic of phosphor for use in high power white‐light‐emitting diodes (wLEDs) is a significant materials challenge. To achieve this goal, a series of red‐emitting carbidonitride phosphors Ca0.992 AlSiN3 − 4/3 x C x :0.008Eu 2+ have been synthesized by high‐temperature solid‐state reaction method. Crystal structure, luminescence properties, and thermal quenching process are investigated. The location of carbon in the lattice is proved by the Raman spectra. The preferential crystallographic site of carbon is validated by the first‐principles density functional theory calculations combining the Rietveld refinement. With carbon doping from x = 0 to x = 0.24, the emission spectra are blue‐shifted from 656.8 to 650.2 nm, and the fitted lifetime of Eu 2+ decreases from 775.3 to 721.7 ns. Replacing nitrogen by carbon enhances thermal quenching characteristic by 8.9% at 300°C. Carbon doping enlarges the thermal ionization energy barriers (EdC ) which is calculated at great length, and suppresses thermal ionization process. A wLED fabricated by the combination of a blue chip with the as‐synthesized red phosphor and LuAG: Ce 3+ green phosphor shows a high color rendering indexes (Ra = 95.9 and R9 = 92). The promising application of Ca0.992 AlSiN3 − 4/3 x C x :0.008Eu 2+ phosphor for wLEDs is proved by all results above.