Combinatorial approach to the development of a single mass YVO(4):Bi(3+),Eu(3+) phosphor with red and green dual colors for high color rendering white light-emitting diodes.
Instead of developing a novel red phosphor individually, this work proposes the production of white light by combining a near-ultraviolet/ultraviolet diode chip with blue and special yellow phosphors: the yellow phosphor includes the red and green components with high color saturation. The availability of this scheme is demonstrated by preparing a white light-emitting diode (WLED) with color rendering index (Ra) up to 90.3. The desired single-mass yellow phosphor is successfully screened out from the YVO(4):Bi(3+),Eu(3+) system by using a combinatorial chemistry approach. When the emission color and luminous efficiency are both considered, the best composition for producing white light is (Y(1-s-t)Bi(s)Eu(t))VO(4) with 0.040 < or = s < or = 0.050 and 0 < t < or = 0.015. The red component that is required for a high-Ra WLED is obtained through sensitizing luminescence of Eu(3+) by Bi(3+) in a YVO(4) host; meanwhile, both Bi(3+) and Eu(3+) emission are improved by keeping the Bi(3+) and Eu(3+) contents close to the critical concentration.
Chen
Lei
L
Department of Chemistry, National Taiwan University, Taipei, Taiwan.
Chen
Kuo-Ju
KJ
Lin
Chun-Che
CC
Chu
Cheng-I
CI
Hu
Shu-Fen
SF
Lee
Min-Hung
MH
Liu
Ru-Shi
RS
D001729:Bismuth / Q000737:chemistry*; D020650:Combinatorial Chemistry Techniques; D005063:Europium / Q000737:chemistry*; D008027:Light; D010758:Phosphorus / Q000737:chemistry*; D054852:Small Molecule Libraries; D017968:Vanadium Compounds / Q000737:chemistry*; D015019:Yttrium / Q000737:chemistry*
D054852:Small Molecule Libraries; D017968:Vanadium Compounds; D010758:Phosphorus; D005063:Europium; D015019:Yttrium; D001729:Bismuth