Laser excitation of red, green, blue and trichromatic white rare-earth phosphors for solid-state lighting applications

Abstract Phosphors for solid-state lighting, based on a number of different compositional schemes and driven by light from blue light-emitting diodes (LEDs) are widely used for lighting applications. The low efficiency of pump LEDs at high drive currents (droop effect) limits the amount of light produced by conventional LED and phosphor combination. Pumping with laser diodes (LDs) can circumvent this limitation. In this paper we report on the characterisation of individual and a mixture of KEu(WO 4 ) 2 (red), BaMg 2 Al 16 O 27 :Eu, Mn (green) and (Sr,Mg) 2 SiO 4 :Eu (blue) phosphors, excited by a CW-driven LD operating at 404 nm. The activator ion in each of these phosphors is, respectively, Eu 3+ , Mn 2+ and Eu 2+ . Characteristics of light produced with each phosphor, variations with incident light power and phosphor temperature as well as effects from phosphor ageing are described. Results of comparison between pumping with coherent and incoherent light at the same wavelength are also described.

[1]  Jun Zhou,et al.  Energy transfer between Eu–Mn and photoluminescence properties of Ba0.75Al11O17.25–BaMgAl10O17:Eu2+,Mn2+ solid solution , 2010 .

[2]  Soo-Yeon Seo,et al.  Y 3Al5 O 12 : Ce0.05 Phosphor Coatings on Gallium Nitride for White Light Emitting Diodes , 2003 .

[3]  J. Hofkens,et al.  Oxyfluoride glass (SiO 2 -PbF 2 ) co-doped with Ag nanoclusters and Tm 3+ ions for UV-driven, Hg-free, white light generation with a tuneable tint , 2014 .

[4]  Han-Youl Ryu,et al.  Effect of current spreading on the efficiency droop of InGaN light-emitting diodes. , 2011, Optics express.

[5]  M. Hon,et al.  Luminescent Properties of Cerium-Activated Garnet Series Phosphor: Structure and Temperature Effects , 2008 .

[6]  Young Jin Kim,et al.  Crystal structure and variation of luminescence properties of (Ba,Ca)Si 7 N 10 :Eu 2+ as a function of the Eu and Ca concentration , 2014 .

[7]  M. Craford,et al.  Status and Future of High-Power Light-Emitting Diodes for Solid-State Lighting , 2007, Journal of Display Technology.

[8]  C. Yeh,et al.  Light Converting Inorganic Phosphors for White Light-Emitting Diodes , 2010, Materials.

[9]  Shen Guang-di,et al.  Color rendering and luminous efficacy of trichromatic and tetrachromatic LED-based white LEDs , 2007 .

[10]  C. Summers,et al.  Controlling energy transfer processes and engineering luminescence efficiencies with low dimensional doping , 2012 .

[11]  Chengzheng Jia,et al.  A Eu(2+) and Mn(2+)-coactivated fluoro-apatite-structure Ca6Y2Na2(PO4)6F2 as a standard white-emitting phosphor via energy transfer. , 2014, Dalton transactions.

[12]  Jorg Hader,et al.  On the origin of IQE‐‘droop’ in InGaN LEDs , 2009 .

[13]  M. Shur,et al.  Introduction to Solid-State Lighting , 2002 .

[14]  Jun Lin,et al.  Color-Tunable Luminescence and Energy Transfer Properties of Ca9Mg(PO4)6F2:Eu2+, Mn2+ Phosphors for UV-LEDs , 2014 .

[15]  E. Schubert,et al.  Efficiency droop in light‐emitting diodes: Challenges and countermeasures , 2013 .

[16]  S. A. Stockman,et al.  Performance of high-power AlInGaN light emitting diodes , 2001 .

[17]  P. Smet,et al.  Selecting Conversion Phosphors for White Light-Emitting Diodes , 2011 .

[18]  Baojiu Chen,et al.  SiO2 effect on spectral and colorimetric properties of europium doped SrO2–MgO–xSiO2 (0.8 ⩽ x ⩽ 1.6) phosphor for white LEDs , 2009 .

[19]  B. Smets,et al.  The luminescence properties of Eu2+- and Mn2+-doped barium hexaaluminates , 1986 .

[20]  Shuji Nakamura,et al.  Efficient and stable laser-driven white lighting , 2013 .

[21]  Sun-il Mho,et al.  Warm-white-light emitting diode utilizing a single-phase full-color Ba3MgSi2O8:Eu2+,Mn2+ phosphor , 2004 .