Color-Tunable and Highly Luminous N(3-)-Doped Ba2-xCaxSiO4-δN2/3δ:Eu(2+) (0.0 ≤ x ≤ 1.0) Phosphors for White NUV-LED.
In the search for well-defined phosphor materials for white NUV-LEDs, the highly enhanced luminous efficacy by N(3-) doping as well as color tunability via Ca substitution has been successfully obtained in Ba2-xCaxSiO4-δN2/3δ:Eu(2+) (x = 0.0, 0.5, 0.8, 1.0) phosphors. With increasing Ca-substitution rate, the crystal structures of the phosphor materials are changed from the primitive orthorhombic structure to the hexagonal one, so that the CIE coordinates move from bluish-green (at Ca = 0.0), to blue (at Ca = 0.5), and finally to near white region (at Ca = 0.8 and 1.0) in these materials. In combination with the results from X-ray photoelectron spectroscopy (XPS) and infrared (IR) spectroscopy, the elemental distribution of the phosphor materials found from secondary-ion mass spectrometry (SIMS) directly indicates that the N(3-) ions are partially substituted for O(2-) ions into the crystal lattice of alkaline-earth orthosilicates and thus critically improves the color-tunable photoluminescence (PL) and electroluminescence (EL) efficiency of the phosphor materials for white NUV-LEDs. The newly found "the N(3-) doping and color-tunable effect" on large PL and EL enhancement may provide a platform in the discovery of new efficient phosphors for solid state lighting.
Donghyeon
D
Kim
Busan Center, Korea Basic Science Institute , Busan 46742, Republic of Korea.
Jong-Seong
JS
Bae
Busan Center, Korea Basic Science Institute , Busan 46742, Republic of Korea.
Tae Eun
TE
Hong
Institute of Applied Physics and Materials Engineering, University of Macau , Avenida da Universidade, Taipa, Macau, China.
Kwun Nam
KN
Hui
Institute of NT.IT Fusion Technology, Ajou University , Suwon 16499, Republic of Korea.
Sungyun
S
Kim
Advanced Materials Division, Korea Research Institute of Chemical Technology (KRICT) , 141, Gajeong-ro, Yuseong-gu, Daejeon 34114, Republic of Korea.
Chang Hae
CH
Kim
Jung-Chul
JC
Park
Ba2SiO4:Eu2+; Ca substitution; N3−-ion doping; color-tunable; highly luminous PL and EL