Photoluminescence properties of novel Ba2Lu5B5O17:Eu3+ red emitting phosphors with high color purity for near-UV excited white light emitting diodes. Issue 53 (28th August 2018)

• Record Type: Journal Article
• Authors: Annadurai, G.; Devakumar, Balaji; Guo, Heng; Li, Bin; Sun, Liangling; Huang, Xiaoyong
• Is Part Of: RSC advances. Volume 8:Issue 53(2018)
• Page Start: 30396
• Page End: 30403
• Publication Date: 2018-08-28
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c8ra06457a
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Novel Ba2 Lu5 B5 O17 :Eu 3+ red emitting phosphors with high color purity were prepared for near-UV excited white light emitting diodes. Abstract : A series of new red-emitting Ba2 Lu4.98− x Eu x La0.02 B5 O17 (0.1 ≤ x ≤ 1.0) phosphors were synthesized via the high-temperature solid-state reaction method. The phase formation of the as-synthesized Ba2 Lu4.48 Eu0.5 La0.02 B5 O17 phosphor was confirmed by powder X-ray diffraction analysis. It was found that La 3+ doping resulted in the reduction of LuBO3 impurities and thus pure phase Ba2 Lu5 B5 O17 was realised. The morphology of Ba2 Lu4.48 Eu0.5 La0.02 B5 O17 phosphors was studied by field emission scanning electron microscopy (FE-SEM). As a function of Eu 3+ concentration the photoluminescence spectra and decay lifetimes were investigated in detail. Under excitation at 396 nm, a dominant red emission peak located at 616 nm ( 5 D0 → 7 F2 ) indicated that Eu 3+ ions mainly occupied low symmetry sites with a non-inversion center in Ba2 Lu4.48 Eu0.5 La0.02 B5 O17 . The optimal Eu 3+ ion concentration was found to be x = 0.5 and the critical distance of Eu 3+ was determined to be 6.55 Å. In addition, the concentration quenching takes place via dipole–dipole interactions. The phosphors exhibited good CIE (Commission International de I'Eclairage) color coordinates ( x = 0.643, y = 0.356) situated in the red region and a high color purity of 97.8%. Furthermore, the internal quantum efficiency and the thermal stability of Ba2 Lu4.48 Eu0.5 La0.02 B5 O17 phosphors were also investigated systematically. The results suggest that Ba2 Lu4.48 Eu0.5 La0.02 B5 O17 may be a potential red phosphor for white light-emitting diodes.