Abstract
The coating of phosphor-in-glass with high refractive index was successfully fabricated for enhanced light extraction efficiency of white LEDs through a multilayer screen-printing and low-temperature sintering procedure. The effects of sintering temperature on the B2O3–SiO2–ZnO glass coating and YAG:Ce phosphor concentration on the phosphor-in-glass coating were investigated. The B2O3–SiO2–ZnO glass matrix possesses low glass transition temperature and appropriate thermal expansion coefficient. With the addition of La2O3 and WO3, high refractive index of 1.82 at 460 nm is acquired. The amorphous glass coating, sintered at 600 °C, yields an optimized transmittance of 50%. Furthermore, negligible thermal degradation is observed in the phosphor-in-glass coating, and the emission peak under the 460-nm excitation is at ~540 nm. When increasing the concentration of phosphor, luminous efficacy and correlated color temperature are both improved, but color rendering index is deteriorated. As the refractive index increases, the light extraction efficiency of white LEDs is enhanced due to the reason that the match of refractive index between the glass matrix and the phosphor decreases the total internal reflection at the interface.
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References
Kim C, Park H-A, Jang HW, Chung WJ, Kim SY (2014) All-in-one-type organic light-emitting diodes for color tuning using phosphor in glasses with Pb-free silicate powders. Curr Appl Phys 14(12):1677–1681
Huang B, Ma Y, Qian S, Zou D, Zheng G, Dai Z (2014) Luminescent properties of low-temperature-hydrothermally-synthesized and post-treated YAG:Ce (5%) phosphors. Opt Mater 36(9):1561–1565
Lin H, Wang B, Xu J, Zhang R, Chen H, Yu Y, Wang Y (2014) Phosphor-in-glass for high-powered remote-type white AC-LED. ACS Appl Mater Interfaces 6(23):21264–21269
Fujita S, Tanabe S (2015) Glass–ceramics and solid-state lighting. Int J Appl Glass Sci 6(4):356–363
Liu G, Tian Z, Chen Z, Wang H, Zhang Q, Li Y (2015) CaAlSiN3: Eu2+ phosphors bonding with bismuth borate glass for high power light excitation. Opt Mater 40:63–67
Chen L-Y, Chang J-K, Cheng W-C, Huang J-C, Huang Y-C, Cheng W-H (2015) Chromaticity tailorable glass-based phosphor-converted white light-emitting diodes with high color rendering index. Opt Express 23(15):A1024–A1029
Tsai C-C (2015) Process dependent luminescence characteristics of low-temperature Ce3+: YAG doped glass for phosphor-converted white-light-emitting diodes. Optik 126(6):655–658
Peng Y, Li R, Cheng H, Chen Z, Li H, Chen M (2017) Facile preparation of patterned phosphor-in-glass with excellent luminous properties through screen-printing for high-power white light-emitting diodes. J Alloy Compd 693:279–284
Zou J, Yang B, Li J, Zhu S, Qian X, Wang F (2016) Effect of Sr/Ca substitution on phase structure and photoluminescence properties of micro-SrxCa1−xAlSiN3: Eu2+ phosphor for high CRI white LEDs. Ceram Int 42(13):14956–14962
Segawa H, Hirosaki N, Ohki S, Deguchi K, Shimizu T (2015) Exploration of metaphosphate glasses dispersed with Eu-doped SiAlON for white LED applications. Opt Mater 42:399–405
Ma M, Mont FW, Yan X, Cho J, Schubert EF, Kim GB, Sone C (2011) Effects of the refractive index of the encapsulant on the light-extraction efficiency of light-emitting diodes. Opt Express 19(19):A1135–A1140
Unithrattil S, Lee KH, Im WB (2014) Enhanced luminescence of Ca14Mg2Si8O28+dN4−d: Eu2+ phosphors by codoping Ce3+, Mn2+ for white LEDs and their energy-transfer mechanism. J Am Ceram Soc 97(3):874–879
Zhong J, Chen D, Zhou Y, Wan Z, Ding M, Ji Z (2016) Stable and chromaticity-tunable phosphor-in-glass inorganic color converter for high-power warm white light-emitting diode. J Eur Ceram Soc 36(7):1705–1713
Wang S, Chen X, Chen M, Zheng H, Yang H, Liu S (2014) Improvement in angular color uniformity of white light-emitting diodes using screen-printed multilayer phosphor-in-glass. Appl Opt 53(36):8492–8498
Chen D, Xiang W, Liang X, Zhong J, Yu H, Ding M, Lu H, Ji Z (2015) Advances in transparent glass–ceramic phosphors for white light-emitting diodes-a review. J Eur Ceram Soc 35(3):859–869
Zhuo Y, Li H, Xu X, Chen M, Xiong D, Long Y, Chen S, Li R, Liu Z (2017) Enhanced luminous efficiency of multilayer gradient refractive index phosphor in P2O5–ZnO–B2O3–BaO glass for white light-emitting diode packages. J Non Cryst Solids 471:215–221
Xu X, Li H, Zhuo Y, Li R, Tian P, Xiong D, Chen M (2017) Tunable chromaticity and enhanced luminous efficacy of white LEDs with phosphor-in-glass coating via multilayer screen-printing. Ceram Int 43(16):13569–13575
Krishnapuram P, Jakka SK, Thummala C, Lalapeta RM (2012) Photoluminescence characteristics of Eu2O3 doped calcium fluoroborate glasses. J Mol Struct 1028:170–175
Kaewkhao J, Boonin K, Yasaka P, Kim HJ (2015) Optical and luminescence characteristics of Eu3+ doped zinc bismuth borate (ZBB) glasses for red emitting device. Mater Res Bull 71:37–41
Mandal AK, Balaji S, Sen R (2014) Microwave and conventional preparation of Zinc borate glass: Eu3+ ion as luminescent probe. J Alloy Compd 615:283–289
Lin Z, Lin H, Xu J, Huang F, Chen H, Wang B, Wang Y (2015) Highly thermal-stable warm w-LED based on Ce: YAG PiG stacked with a red phosphor layer. J Alloy Compd 649:661–665
Park H-A, Lee YK, Im WB, Heo J, Chung WJ (2015) Phosphor in glass with Eu3+ and Pr3+-doped silicate glasses for LED color conversion. Opt Mater 41:67–70
Chen H, Lin H, Xu J, Wang B, Lin Z, Zhou J, Wang Y (2015) Chromaticity-tunable phosphor-in-glass for long-lifetime high-power warm w-LEDs. J Mater Chem C 3(31):8080–8089
Burgin J, Jubera V, Debeda H, Glorieux B, Garcia A, Lucat C (2011) Screen-printed phosphor coatings for white LED emission. J Mater Sci 46(7):2235–2241. doi:10.1007/s10853-010-5062-7
Peng Y, Li R, Guo X, Zheng H, Chen M (2016) Optical performance improvement of phosphor-in-glass based white light-emitting diodes through optimized packaging structure. Appl Opt 55(29):8189–8195
Xiang R, Liang X, Xi Q, Yuan Z, Chen C, Xiang W (2016) A chromaticity-tunable white LED by screen-printing red phosphor coating on PiG plates. Ceram Int 42(16):19276–19282
Zhang B, Chen Q, Song L, Li H, Hou F, Zhang J (2008) Fabrication and properties of novel low-melting glasses in the ternary system ZnO–Sb2O3–P2O5. J Non Cryst Solids 354(18):1948–1954
Pahari B, Iftekhar S, Jaworski A, Okhotnikov K, Jansson K, Stevensson B, Grins J, Eden M (2012) Composition-property-structure correlations of scandium aluminosilicate glasses revealed by multinuclear 45Sc, 27Al, and 29Si solid-state NMR. J Am Ceram Soc 95(8):2545–2553
Koudelka L, Roesslerova I, Kalenda P, Mosner P, Montagne L, Revel B (2016) Characterization and structural investigation of lead borophosphate glasses modified by tungsten oxide. J Alloy Compd 658:377–384
Zhang L, Lu Z, Zhu J, Yang H, Han P, Chen Y, Zhang Q (2012) Citrate sol–gel combustion preparation and photoluminescence properties of YAG:Ce phosphors. J Rare Earths 30(4):289–296
Jain D, Sudarsan V, Vatsa RK, Pillai CGS (2009) Luminescence studies on ZnO–P2O5 glasses doped with Gd2O3: Eu nanoparticles and Eu2O3. J Lumin 129(5):439–443
Kirsch R (2001) Titanium metals, their behaviour and basic corrosion tests in the glass melt and atmosphere. Glass Sci Technol Glastechnische Berichte 74(6):166–176
Wang L, Jin S, Yang X, Gu L, Zhang Q (2016) Composition-induced tunable white emission in Ce/Tb/Eu co-doped lithium–barium borophosphate glasses. J Mater Sci Mater Electron 27(2):1473–1478
Zhang R, Lin H, Yu Y, Chen D, Xu J, Wang Y (2014) A new-generation color converter for high-power white LED: transparent Ce3+: YAG phosphor-in-glass. Laser Photonics Rev 8(1):158–164
Yi S, Chung WJ, Heo J (2014) Stable and color-tailorable white light from blue LEDs using color-converting phosphor–glass composites. J Am Ceram Soc 97(2):342–345
Seo J, Kim S, Kim Y, Iqbal F, Kim H (2014) Effect of glass refractive index on light extraction efficiency of light-emitting diodes. J Am Ceram Soc 97(9):2789–2793
Zhao X, Wang X, Lin H, Wang Z (2008) A new approach to estimate refractive index, electronic polarizability, and optical basicity of binary oxide glasses. Phys B Condens Matter 403(13–16):2450–2460
Zhang S, Xu M, Chen X, Zhang Y, Calvez L, Zhang X, Xu Y, Huai Y, Jin Y (2013) Enhanced thermostability, thermo-optics, and thermomechanical properties of barium gallo–germanium oxyfluoride glasses and glass–ceramics. J Am Ceram Soc 96(8):2461–2466
Wang GN, Xu SQ, Dai SX, Zhang JJ, Jiang ZH (2004) Thermal stability and spectroscopic properties of Yb3+-doped zinc–tungsten–tellurite glasses. J Alloy Compd 373(1–2):246–251
Chimalawong P, Kaewkhao J, Kedkaew C, Limsuwan P (2010) Optical and electronic polarizability investigation of Nd3+ -doped soda-lime silicate glasses. J Phys Chem Solids 71(7):965–970
Kim B-N, Hiraga K, Morita K, Yoshida H, Miyazaki T, Kagawa Y (2009) Microstructure and optical properties of transparent alumina. Acta Mater 57(5):1319–1326
Boulesteix R, Maitre A, Baumard JF, Rabinovitch Y, Reynaud F (2010) Light scattering by pores in transparent Nd: YAG ceramics for lasers: correlations between microstructure and optical properties. Opt Express 18(14):14992–15002
Kim Y, Kim S, Iqbal F, Yie H, Kim H (2015) Effect of transmittance on luminescence properties of phosphor-in-glass for LED packaging. Opt Express 23(3):A43–A50
Lu C, Jin H, Liang X, Xiang W, Zhong J, Dong Y (2012) A novel green–yellow emitting phosphor Ca1.5Y1.5Al3.5Si1.5O12:Ce3+ and its luminescence properties. J Rare Earths 30(7):647–650
Yang C, Liang X, Di X, Li P, Hu G, Cao R, Xiang W (2016) Facile fabrication and luminescence characteristics of Ce:YAG phosphor glass thick films coated on a glass substrate for white LEDs. Ceram Int 42(13):14526–14532
Gong X, Huang J, Chen Y, Lin Y, Luo Z, Huang Y (2014) Novel garnet-structure Ca2GdZr2(AlO4)(3):Ce3+ phosphor and its structural tuning of optical properties. Inorg Chem 53(13):6607–6614
Gupta KVK, Muley A, Yadav P, Joshi CP, Moharil SV (2011) Combustion synthesis of YAG:Ce and related phosphors. Appl Phys B Lasers Opt 105(2):479–484
Dorenbos P (2002) 5d-level energies of Ce3+ and the crystalline environment. IV. Aluminates and “simple” oxides. J Lumin 99(3):283–299
Liu GH, Zhou ZZ, Shi Y, Liu Q, Wan JQ, Pan YB (2015) Ce: YAG transparent ceramics for applications of high power LEDs: thickness effects and high temperature performance. Mater Lett 139:480–482
Pradal N, Chadeyron G, Potdevin A, Deschamps J, Mahiou R (2013) Elaboration and optimization of Ce-doped Y3Al5O12 nanopowder dispersions. J Eur Ceram Soc 33(10):1935–1945
Zhang Q, Ni H, Wang L, Xiao F (2016) Luminescence properties and energy transfer of GdAl3(BO3)(4):Ce3+, Tb3+ phosphor. Ceram Int 42(5):6115–6120
Li H, Xu XJ, Li Y, Wu S, Tian PJ, Tian Y (2016) Preparation and luminescent properties of the coating of phosphor in lead-free glass by multilayer screen-printing. J Alloy Compd 684:372–378
Li R, Y-z Wang, Z-y Mao, Wang D-J (2015) Relation of thickness and luminescence in F-modified silicate based remote phosphor coating for white light emitting diodes. J Mater Sci Mater Electron 26(2):884–890
Mont FW, Schubert EF (2010) High-refractive-index TiO2-nanoparticle-loaded encapsulants for light-emitting diodes (vol 103, 083120, 2008). J Appl Phys 107(10):109901
Segawa H, Yoshimizu H, Hirosaki N, Inoue S (2011) Fabrication of silica glass containing yellow oxynitride phosphor by the sol–gel process. Sci Technol Adv Mater 12(3):034407
Zhou Y, Chen D, Tian W, Ji Z (2015) Impact of Eu3+ dopants on optical spectroscopy of Ce3+: Y3Al5O12-embedded transparent glass–ceramics. J Am Ceram Soc 98(8):2445–2450
Lin Z, Lin H, Xu J, Huang F, Chen H, Wang B, Wang Y (2016) A chromaticity-tunable garnet-based phosphor-in-glass color converter applicable in w-LED. J Eur Ceram Soc 36(7):1723–1729
Acknowledgements
This work was supported by the National Natural Science Foundation of China (51372179), the Hubei Province Foreign Science and Technology Project (2016AHB027), and the Science and Technology Planning Project of Hubei Province (2014BAA136).
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Xu, X., Li, H., Zhuo, Y. et al. High refractive index coating of phosphor-in-glass for enhanced light extraction efficiency of white LEDs. J Mater Sci 53, 1335–1345 (2018). https://doi.org/10.1007/s10853-017-1571-y
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DOI: https://doi.org/10.1007/s10853-017-1571-y