Preparation, electronic structure, and photoluminescent properties of Eu 2+ activated BaSi 2 O 5 powder phosphors for solid-state lighting

The green-emitting phosphor BaSi2O5:Eu2+ was synthesized by the conventional solid state reaction. Using the CASTEP code, BaSi2O5 is calculated to be an intermediate band gap semiconductor with an indirect energy gap of about 3. 2 eV. As expected, the calculated optical band gap of BaSi2O5 is lower compared to the experimentally determined values. Eu2+-activated BaSi2O5 phosphor can be excited efficiently over a broad spectral range between 200 and 400 nm, and has an emission peak at 500 nm with a full width at half maximum of 95 nm. The study of concentration-dependent emission intensity shows the optimal concentration of the Eu2+ is 0.05 mol, and that concentration quenching occurs when the Eu2+ content is beyond the critical value. The external quantum efficiency of the optimized BaSi2O5:Eu2+ is 96. 1%, 70. 2% and 62. 1% under excitation at 315, 350 and 365 nm, respectively. The superior optical properties of the sample show the potential as an ultraviolet converting green-emitting phosphor for white light emitting diodes.

[1]  Yebin Xu,et al.  Preparation of nanocrystalline Sr3Al2O6 powders via citric acid precursor , 2007 .

[2]  Q. Yan,et al.  Enhanced light extraction of InGaN LEDs with photonic crystals grown on p-GaN using selective-area epitaxy and nanospherical-lens photolithography , 2013 .

[3]  J. Soubeyroux,et al.  Tristrontium dialuminum hexaoxide: an intricate superstructure of perovskite , 1990 .

[4]  Jie Liu,et al.  A new luminescent material: Li2CaSiO4 : Eu2+ , 2006 .

[5]  J. Koningstein,et al.  The effect of strong crystal fields on the selection rules of electronic raman transitions , 1970 .

[6]  F. Glasser,et al.  Crystal Chemistry of Some AB2O4 Compounds , 1963 .

[7]  H. Sung,et al.  Hydrothermally-mediated preparation and photoluminescent properties of Sr3Al2O6:Eu3+ phosphor , 2006 .

[8]  B. Chiou,et al.  Synthesis of Eu3+-activated yttrium oxysulfide red phosphor by flux fusion method , 2001 .

[9]  Jun Lin,et al.  Synthesis-dependent luminescence properties of Y3Al5O12:Re3+ (Re=Ce, Sm, Tb) phosphors , 2002 .

[10]  Liping Huang,et al.  Low-temperature synthesis of single-phase nanocrystalline YAG:Eu phosphor , 2003 .

[11]  Jie Liu,et al.  Improved optical photoluminescence by charge compensation in the phosphor system CaMoO4: Eu3+ , 2007 .

[12]  Lan Liu,et al.  The new red luminescent Sr3Al2O6:Eu2+ phosphor powders synthesized via sol-gel route by microwave-assisted , 2008 .

[13]  U. V. Varadaraju,et al.  Photoluminescence Studies on Eu2+-Activated Li2SrSiO4a Potential Orange-Yellow Phosphor for Solid-State Lighting , 2006 .

[14]  B. Smets,et al.  2SrO · 3Al2 O 3 : Eu2 + and 1.29 ( Ba , Ca ) O , 6Al2 O 3 : Eu2 + Two New Blue‐Emitting Phosphors , 1989 .

[15]  S. Mho,et al.  Phase studies of SrOAl2O3 by emission signatures of Eu2+ and Eu3+ , 1997 .

[16]  D. Irvine-Halliday.  Solid-state lighting: the only solution for the developing world , 2006 .

[17]  Ha-Kyun Jung,et al.  Luminescent Properties of (Sr, Zn)Al2O4:Eu2+,B3+ Particles as a Potential Green Phosphor for UV LEDs , 2006 .

[18]  U. V. Varadaraju,et al.  Photoluminescence Studies of Eu2+‐Activated Li2SrSiO4 — A Potential Orange‐Yellow Phosphor for Solid‐State Lighting. , 2007 .

[19]  J. R. Jurado,et al.  Combustion Synthesis of Nanometric Powders of LaPO4 and Sr-Substituted LaPO4 , 2005 .

[20]  Yuanhua Lin,et al.  Preparation of the ultrafine SrAl2O4:Eu,Dy needle-like phosphor and its optical properties , 2000 .

[21]  K. Murthy,et al.  Synthesis, characterization and luminescence of Sr3Al2O6 phosphor with trivalent rare earth dopant , 2006 .

[22]  Hee Dong Park,et al.  White light-emitting diodes of GaN-based Sr2SiO4:Eu and the luminescent properties , 2003 .

[23]  S. Enzo,et al.  Structural investigations and luminescence properties of nanocrystalline europium-doped yttrium silicates prepared by a sol–gel technique , 2007 .

[24]  K. Su,et al.  Molecular and polymer precursor routes to manganese-doped zinc orthosilicate phosphors , 1996 .

[25]  Q. Su,et al.  The valence change from RE3+ to RE2+ (REEu, Sm, Yb) in SrB4O7: RE prepared in air and the spectral properties of RE2+ , 1993 .

[26]  A. Cheetham,et al.  Preparation and characterization of Pd2Sn nanoparticles , 2007 .

[27]  H. Ling,et al.  Preparation of Y 3Al5 O 12 ‐ Based Phosphor Powders , 1987 .

[28]  K. Nonaka,et al.  Intense visible light emission from Sr3Al2O6:Eu,Dy , 1998 .

[29]  Shougang Wang,et al.  Preparation of Y3Al5O12:Eu phosphors by citric–gel method and their luminescent properties , 2002 .

[30]  Bo Sun,et al.  Rapid formation of red long afterglow phosphor Sr3Al2O6:Eu2+, Dy3+ by microwave irradiation , 2007 .