Luminescence properties of NaGd(PO3)4:Eu3+ and energy transfer from Gd3+ to Eu3+

The luminescence properties of polyphosphates NaEuxGd(1−x)(PO3)4 (x = 0–1.00) and the energy transfer from Gd3+ to Eu3+ were studied. In undoped NaGd(PO3)4 sample, the photon cascade emission of Gd3+ was observed under 8S7/2 → 6GJ excitation (201 nm) in which the emission of a red photon due to 6GJ → 6PJ transition is followed by an ultraviolet photon emission due to 6PJ → 8S7/2 transition. When part of Gd3+ ions in the host NaGd(PO3)4 were substituted by Eu3+ ions, the NaGd(PO3)4:Eu3+ sample showed intensive red emission under 172-nm vacuum-ultraviolet (VUV) excitation which is suitable for mercury-free fluorescent lamps and plasma display panel applications. Based on the VUV–visible spectroscopic characteristics and the luminescence decay properties of NaGd(PO3)4:Eu3+, it was found that the quantum cutting by a two-step energy transfer from Gd3+ to Eu3+ can improve the red emission of Eu3+ ions under VUV excitation but only a part of the excitation energy in the excited 6PJ states within Gd3+ ions can be transferred to Eu3+ ions for its red emission, and the nonradiative energy transfer efficiencies from the excited 6PJ states within Gd3+ to Eu3+ were calculated.

[1]  J. G. Solé,et al.  An Introduction to the Optical Spectroscopy of Inorganic Solids , 2005 .

[2]  N. Zouari,et al.  Synthesis and crystal structure of sodium–bismuth polyphosphate NaBi(PO3)4 , 2005 .

[3]  W. Ryba-Romanowski,et al.  Conversion of infrared radiation into red emission in YVO4:Yb,Ho , 2001 .

[4]  A. Meijerink,et al.  Visible quantum cutting in LiGdF4:Eu3+ through downconversion , 1999, Science.

[5]  H. Seo,et al.  Host sensitization ofGd3+ions in yttrium and scandium borates and phosphates: Application to quantum cutting , 2006 .

[6]  Andries Meijerink,et al.  Vacuum-ultraviolet spectroscopy and quantum cutting for Gd 3 + in LiYF 4 , 1997 .

[7]  G. Blasse.  On the Eu3+ Fluorescence of Mixed Metal Oxides. IV. The Photoluminescent Efficiency of Eu3+‐Activated Oxides , 1966 .

[8]  M. Ferid,et al.  Crystal structure and spectroscopic studies of NaGd(PO3)4 , 2005 .

[9]  Stanley S. Ballard,et al.  Techniques of Vacuum Ultraviolet Spectroscopy , 1967 .

[10]  K. Toda.  Recent research and development of VUV phosphors for a mercury-free lamp , 2006 .

[11]  H. Hong.  Crystal structure of NdLiP4O12 , 1975 .

[12]  V. Petrov,et al.  Growth, spectroscopy and laser operation of Yb:KGd(PO(3))(4) single crystals. , 2007, Optics Express.

[13]  J. Gavaldà,et al.  Crystal Growth, Structural Characterization, and Linear Thermal Evolution of KGd(PO3)4 , 2005 .

[14]  Bing Han,et al.  Intensive emission of Dy3+ in NaGd(PO3)4 for Hg-free lamps application. , 2008, Optics express.

[15]  S. Jang,et al.  Luminescent properties of (Y,Gd)BO3:Bi3+,RE3+ (RE=Eu, Tb) phosphor under VUV/UV excitation , 2006 .

[16]  N. Zouari,et al.  Synthesis and crystal structure of a new form of potassium–bismuth polyphosphate KBi(PO3)4 , 2003 .

[17]  D. Wiechert,et al.  Quantum efficiency of down-conversion phosphor LiGdF4 : Eu , 2001 .

[18]  Q. Su,et al.  NaGd(PO3)4:Tb3+ – A new promising green phosphor for PDPs application , 2008 .

[19]  C. Ronda,et al.  Luminescence : from theory to applications , 2008 .

[20]  R. D. Shannon.  Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides , 1976 .

[21]  Houcine Naïli,et al.  Synthesis and Crystal Structure of a New Potassium−Gadolinium Cyclotetraphosphate, KGdP4O12 , 2003 .