Y 2 O 2 S:Eu 3+ PDP YBO 3 :Tb 3+ (Y,Gd)

Transcription

1 44 Panasonic Technical Journal Vol. 62 No. 1 May 2016 Line-emitting Phosphors for High-Performance LED Lighting Systems Shozo Oshio Natsuki Sato Takeshi Abe Keiichi Yamazaki LEDLight Emitting Diode % LED 555 nm620 nm A feasibility study on phosphors that produce line emissions has been carried in an attempt to improve their efficiency by up to several ten percent in theory. The aim is to use them in high-performance Light Emitting Diode (LED) lighting systems. This study is a pioneering work to create novel phosphor materials that can convert the blue light of an LED to green- or red line-emissions. It focuses on physical phenomena called energy transfer which luminescent ions have. This study has demonstrated the presence of phosphor materials which convert violet or blue light to green- or red line-emissions having an emission peak at around 555 nm or 620 nm. This paper describes the luminescence properties that novel phosphors which emit green- or red line-emissions have, and mentions the possibility of putting these phosphors to practical use. LEDLight Emitting Diode LED LED Y 3 Al 5 O 12 :Ce 3+ YAG (Sr,Ca)AlSiN 3 :Eu 2+ SCASN [1] LED3 3 3 [2] LED3LED [3] 3 PDP Tb 3+ Eu 3+ (La,Ce)PO 4 :Tb 3+ Y 2 O 3 :Eu 3+ Y 3 (Al,Ga) 5 O 12 :Tb 3+ Y 2 O 2 S:Eu 3+ PDPYBO 3 :Tb 3+ (Y,Gd) BO 3 :Eu 3+ [4][5] 4f n 4f n -4f n* [6][7] Mn 4+ K 2 SiF 6 :Mn 4+ KSF [8]-[11]KSF KSF [8]-[11] LED LED 3LED

2 45 10 % 3000 KLED LEDYAGSCASN (La,Ce)PO 4 :Tb 3+ Y 2 O 3 :Eu nm555 nm 610 nm3 Simulated spectral distribution of the illumination light Simulation results of the efficiency and quality of the illumination light PS FCI[12][13] Ra80PS90FCI % 5000 K LED LED[3] [14] Ce 3+ Tb 3+ Eu 3+ Ce 3+ LED Tb3 + Eu 3+ Ra Principle of obtaining line emissions

3 46 Panasonic Technical Journal Vol. 62 No. 1 May 2016 Ce 3+ Tb 3+ Ce nm [4][7] Ce 3+ Tb 3+ [15][16]Eu 3+ Tb nm630 nm Eu 3+ Ce 3+ Eu 3+ [15][16] 4f5d [7] A' 3 B' 2 (C'D' 4 ) 3 A' B'MgZnAl GaC'LiVFeAlGaSiGe D'OF [17][18] Crystal structure of garnet Ce 3+ Tb 3+ Eu 3+ Diagram that illustrates Ce 3+ Tb 3+ Eu 3+ energy transfer Ce 3+ Ca 2 LnZr 2 (AlO 4 ) 3 :LnY, Tb, Eu etc. [19][20]Ce 3+ [21][22] Ca 2 TbZr 2 (AlO 4 ) 3 :Ce nm450 nm 546 nm Ca 2 TbZr 2 (AlO 4 ) 3 :Ce nm480 nm 546 nm

4 47 Excitation and emission spectra of a green line-emitting phosphor 380 nm780 nm 420 nm Ce 3+ Tb 3+ [4][7]Ce 3+ Tb 3+ Ce 3+ Tb 3+ Ca 2 (Tb 0.98 Ce 0.02 )Zr 2 (AlO 4 ) 3 IQE max 35 % IQE max 60 % vol.%4 vol.%2 Ca 2 TbZr 2 (AlO 4 ) 3 :Ce 3+,Eu nm Ca 2 TbZr 2 (AlO 4 ) 3 :Ce 3+,Eu 3+ Ce 3+ Eu 3+ [4][7] Ce 3+ Eu 3+ Ce 3+ Eu 3+ Tb 3+ Ca 2 (Tb 0.86 Ce 0.06 Eu 0.08 )Zr 2 (AlO 4 ) 3 IQE max 30 % Excitation and emission spectra of a red line-emitting phosphor Ca 2 TbZr 2 (AlO 4 ) 3 :Ce 3+,Eu 3+ Eu 3+ Excitation and emission spectra of a yellow line-emitting phosphor

5 48 Panasonic Technical Journal Vol. 62 No. 1 May nm611 nm Ca 2 TbZr 2 (AlO4) 3 :Ce 3+,Eu 3+ Ca 2 TbZr 2 (AlO 4 ) 3 :Ce 3+,Eu 3+ Eu 3+ Tb 3+ :546 nmeu 3+ :611 nmce 3+ Tb 3+ Eu 3+ Eu 3+ Eu 3+ Tb 3+ Tb 3+ Ca 2 (Tb 0.93 Ce 0.06 Eu 0.01 )Zr 2 (AlO 4 ) 3 IQE max 15 % LED Ce 3+ Tb 3+ Eu 3+ LED [1] R.J. Xie et al., Nitride Phosphors and Solid-State Lighting, CRC Press, Boca Raton, 2011, Chapter 1, Chapter 3, Chapter 5. [2] , pp [3] A.A. Setlur, Sensitizing Eu 3+ with Ce 3+ and Tb 3+ to Make Narrow-Line Red Phosphors for Light Emitting Diodes, Electrochemical and Solid-State Letters, vol. 15 no. 6, pp. J25-J27, [4] , 237. [5],496 pp , [6] [7],, 2000, pp [8] A. G. Paulusz, Efficient Mn() Emission in Fluorine Coordination, J. Electrochem. Soc., vol. 120, no. 7, pp , [9] T. Takahashi et al., Mn 4+ -Activated Red Photoluminescence in K 2 SiF 6 Phosphor, J. Electrochem. Soc., vol. 155, no. 12, pp. E183-E188, [10] J.E. Murphy et al., PFS, K 2 SiF 6 :Mn 4+ : the Red-line Emitting LED Phosphor behind GE s TriGain Technology TM Platform, SID Symposium Digest of Technical Papers, vol. 46, no. 1, pp , [11], LED 358, pp.23-26, [12], 8211, pp , [13] K. Hashimoto et al., New Method for Specifying Color-Rendering Properties of Light Sources Based on Feeling of Contrast, COLOR research and application, vol. 32, no. 5, pp , [14] G. Blasse et al., Luminescent Materials, Springer-Verlag, Berlin, 1994, Chapter 5, Chapter 6. [15] Y. Jia, et al., Spectral tuning of the n-uv convertible oxynitride phosphor: orange color emitting realization via an energy transfer mechanism, Phys. Chem. Chem. Phys., vol. 15, no. 33, pp , [16] D. Wen et al., A novel narrow-line red emitting Na 2 Y 2 B 2 O 7 :Ce 3+,Tb 3+,Eu 3+ phosphor with high efficiency activated by terbium chain for near-uv white LEDs, Dalton Trans., vol. 42, no. 47, pp , [17] F.S pp [18] E.S. Grew et al., Nomenclature of the garnet supergroup, American Mineralogist, vol. 98, no. 4, pp , [19] Ca 2 TbZr 2 (AlO 4 ) 3 :Ce p , [20], Ca 2 TbZr 2 (AlO 4 ) 3 :Ce 3+,Eu p , [21] X. Gong et al., Novel Garnet-Structure Ca 2 GdZr 2 (AlO 4 ) 3 : Ce 3+ Phosphor and Its Structural Tuning of Optical Properties, Inorg. Chem., vol. 53, no. 13, pp , [22] X. Wang et al., Synthesis, Structure, and Photoluminescence Properties of Ce 3+ -Doped Ca 2 YZr 2 Al 3 O 12 : A Novel Garnet Phosphor for White LEDs, J. Phys. Chem. C vol. 119, no. 28, pp , 2015.

6 49 Engineering Div., Eco Solutions Company Engineering Div., Eco Solutions Company Engineering Div., Eco Solutions Company Engineering Div., Eco Solutions Company