在我們發表的期刊論文[J. Am. Ceram. Soc., 93, 138 (2010)]中，紅色Ca2.82(VO4)2:0.12Eu3+螢光粉能有效地被波長465 nm的藍光激發，因此可做為應用於結合藍色發光二極體（波長為450～470 nm）的螢光粉轉換白色發光二極體。本博士論文的主要目標在於採用普遍使用之固態反應法開發應用於螢光粉轉換白色發光二極體的下轉換無機螢光粉。我們發現不僅以較大的Ba2+離子[參考J. Am. Ceram. Soc., 93, 138 (2010)]，以較小的Mg2+離子[本論文]取代不高於14.9%的Ca2+離子，亦能夠提昇紅色Ca2.82(VO4)2:0.12Eu3+螢光粉的積分下轉換發光強度，可知晶格擴張與縮減均能降低Ca2.82(VO4)2:0.12Eu3+螢光粉中Eu3+離子的對稱性；此發現預期可用於提昇其它摻雜Eu3+離子的螢光粉之Eu3+發光強度。為了進一步探討Eu3+離子的上轉換行為，我們添加Yb3+離子作為增感劑。有趣的是，上轉換激發機制提升了下轉換激發下從5D1,2,3能階釋放的Eu3+發光強度，此現象導致最佳化(Ca0.742Mg0.067)2.82(VO4)2:0.36Yb3+,0.12Eu3+螢光粉隨著激發機制由下轉換變為上轉換，其發光顏色從紅色轉變為近暖白色。此外，我們發現以Sr2+離子取代3%的Ca2+離子能夠在波長465 nm激發下提昇Ca2.82(VO4)2:0.12Eu3+螢光粉的紅色發光強度達14%。傳統用於得知不同離子間(I0/I － C作圖)與相同離子間(log(C/I) － logC作圖)能量轉移機制的擬合方法須分別假設I0/I ≫ 1 與βCθ/3 ≫ 1（I0 與 I 分別為能量接受者不存在與存在下能量供給者的發光強度；C為能量供給者與能量接受者的濃度總合；θ表示多極反應的形式；β為對應各反應的常數）。相較於傳統用於探討多極能量轉移的擬合方法，本論文提出的改良方法呈現更精確且可信的結果。在屏除I0/I ≫ 1的前提下，根據(I0/I － 1) － C圖形的擬合結果，Sm3+離子轉移能量給Eu3+離子的二極－二極反應之濃度相依性首度被證實，此外，我們發現Harris模型為一可選擇的方式，讓我們在擬合I/C － C圖形時跳脫βCθ/3 ≫ 1的必要條件，藉由此模型，可知(Ca0.97Sr0.03)3(VO4)2主體中Sm3+離子波長為951 nm之發光強度的濃度淬滅來自於三體的二極－二極反應。

Our previous work [J. Am. Ceram. Soc., 93, 138 (2010)] reported a red phosphor Ca2.82(VO4)2:0.12Eu3+ which was well-excited by 465-nm blue light and was therefore a candidate for application to the phosphor-converted WLED (pc-WLED) with a blue chip (450-470 nm). On the basis of Ca2.82(VO4)2:0.12Eu3+, we sought to develop down-shifting (DS) inorganic phosphors for use in pc-WLEDs by the commonly-used solid-state reaction method, which was the main purpose of the present research. We found that substitution of not only a larger ion like Ba2+ [J. Am. Ceram. Soc., 93, 138 (2010)] but also a smaller one like Mg2+ (this research) replacing no ＞ 14.9% Ca2+ ions could enhance the integrated DS emission intensity of red phosphor Ca3(VO4)2:0.12Eu3+, indicating that both lattice expansion and contraction could decrease the site symmetry of Eu3+ in Ca3(VO4)2:0.12Eu3+ phosphor. This finding is anticipated to improve the Eu3+ emission intensity of other Eu3+-doped phosphors. To further investigate Eu3+ up-conversion (UC) behaviors, Yb3+ ion was used as a sensitizer. Interestingly, the enhanced Eu3+ emission from 5D1,2,3 states under UC excitation was observed as compared to that under DC excitation. This phenomenon led to the variation in the emission color of the optimized (Ca0.742Mg0.067)2.82(VO4)2:0.36Yb3+,0.12Eu3+ phosphor from red to near warm white as the excitation mechanism changed from DS to UC. Additionally, it was found that substitution of 3% Sr2+ replacing Ca2+ enhanced the red emission intensity of Ca2.82(VO4)2:0.12Eu3+ by 14% under 465-nm excitation. The conventional methods to determine multipolar mechanisms responsible for the energy transfer between different ions (I0/I － C plot) and alike ions (log(C/I) － logC plot) supposed hypotheses of I0/I ≫ 1 and βCθ/3 ≫ 1, respectively, where I0 and I are the emission intensity of the energy donor in the absence and presence of the acceptor; C is the sum of both energy donor and acceptor contents; θ represents the type of multipolar interactions, and β is a constant for each interaction. Compared with the conventional methods, the modified methods for investigation of the multipolar energy transfer proposed in this research demonstrated more precise and valid results. Excluding the prerequisite of I0/I ≫ 1, the concentration-dependent dipole-dipole multipolar interactions for the Sm3+ → Eu3+ energy transfer were observed for the first time based on the fitting results of (I0/I － 1) － C plots. Additionally, the Harris model was found to be an alternative way to release us from the prerequisite of βCθ/3 ≫ 1 when fitting the I/C － C plot. And a dipole-dipole multipolar interaction of 3-body type was found to be responsible for the concentration quenching of Sm3+ emission around 951 nm in the (Ca0.97Sr0.03)3(VO4)2 host.

[1] A. K. Levine and F. C. Palilla, “A new, highly efficient red-emitting cathodoluminescent phosphor (YVO4:Eu) for color television,” Appl. Phys. Lett., 5, 118–120 (1964).
[2] G. Blasse and B. C. Grabmaier, Luminescent Materials, Springer-Verlag, Berlin, Germany (1994).
[3] M. Yu, J. Lin, and S. B. Wang, “Effects of x and R3+ on the luminescent properties of Eu3+ in nanocrystalline YVxP1-xO4:Eu3+ and RVO4:Eu3+ thin-film phosphors,” Appl. Phys. A: Mater. Sci. Process., 80, 353–360 (2005).
[4] W. J. Park, M. K. Jung, and D. H. Yoon, “Influence of Eu3+, Bi3+ co-doping content on photoluminescence of YVO4 red phosphors induced by ultraviolet excitation,” Sensor. Actuat. B: Chem., 126, 324–327 (2007).
[5] K. S. Sohn, I. W. Zeon, H. Chang, S. K. Lee, and H. D. Park, “Combinatorial search for new red phosphors of high efficiency at VUV excitation based on the YRO4 (R = As, Nb, P, V) system,” Chem. Mater., 14, 2140–2148 (2002).
[6] C. C. Wu, K. B. Chen, C. S. Lee, T. M. Chen, and B. M. Cheng, “Synthesis and VUV photoluminescence characterization of (Y,Gd)(V,P)O4:Eu3+ as a potential red-emitting PDP phosphor,” Chem. Mater., 19, 3278–3285 (2007).
[7] H. Lai, B. Chen, W. Xu, Y. Xie, X. Wang, and W. Di, “Fine particles (Y,Gd)PxV1-xO4:Eu3+ phosphor for PDP prepared by coprecipitation reaction,” Mater. Lett., 60, 1341–1343 (2006).
[8] C. H. Kim, I. E. Kwon, C. H. Park, Y. J. Hwang, H. S. Bae, B. Y. Yu, C. H. Pyun, and G. Y. Hong, “Phosphors for plasma display panels,” J. Alloys Compd., 311, 33–39 (2000).
[9] C. K. Jörgensen and B. R. Judd, “Hypersensitive pseudoquadrupole transitions in lanthanides,” Mol. Phys., 8, 281–290 (1964).
[10] F. C. Palilla, A. K. Levine, and M. Rinkevics, “Rare earth activated phosphors based on yttrium orthovanadate and related compounds,” J. Electrochem. Soc., 112, 776–779 (1965).
[11] M. A. Aia, “Structure and luminescence of the phosphate-vanadates of yttrium, gadolinium, lutetium, and lanthanum,” J. Electrochem. Soc., 114, 367–370 (1967).
[12] G. Blasse and A. Bril, “Luminescence of phosphors based on host lattices ABO4 (A is Sc, In; B is P, V, Nb),” J. Chem. Phys., 50, 2974–2980 (1969).
[13] S. Neeraj, N. Kijima, and A. K. Cheetham, “Novel red phosphors for solid state lighting; the system BixLn1-xVO4; Eu3+/Sm3+ (Ln = Y, Gd),” Solid State Commun., 131, 65–69 (2004).
[14] M. Nazarov, J. H. Kang, D. Y. Jeon, S. Bukesov, and T. Akmaeva, “Synthesis and luminescent performances of some europium activated yttrium oxide based systems,” Opt. Mater., 27, 1587–1592 (2005).
[15] J. H. Kang, W. B. Im, D. C. Lee, J. Y. Kim, D. Y. Jeon, Y. C. Kang, and K. Y. Jung, “Correlation of photoluminescence of (Y, Ln)VO4:Eu3+ (Ln = Gd and La) phosphors with their crystal structures,” Solid State Commun., 133, 651–656 (2005).
[16] X. Q. Su and B. Yan, “Matrix-induced synthesis and photoluminescence of M3Ln(VO4)3:RE (M = Ca, Sr, Ba; Ln = Y, Gd; RE = Eu3+, Dy3+, Er3+) phosphors by hybrid precursors,” J. Alloys Compd., 421, 273–278 (2006).
[17] X. Xiao and B. Yan, “Chemical co-precipitation of hybrid precursors to synthesize Eu3+/Dy3+ activated YNbxP1-xO4 and YNbxV1-xO4 microcrystalline phosphors,” J. Non. Cryst. Solids, 352, 3047–3051 (2006).
[18] H. Zhang, M. Lü, Z. Xiu, G. Zhou, S. Wang, Y. Zhou, and S. Wang, “Influence of processing conditions on the luminescence of YVO4:Eu3+ nanoparticles,” Mater. Sci. Eng. B, 130, 151–157 (2006).
[19] L. Tian and S. I. Mho, “Enhanced photoluminescence of YVO4:Eu3+ by codoping the Sr2+, Ba2+ or Pb2+ ion,” J. Lumin., 122-123, 99–103 (2007).
[20] W. J. Park, M. K. Jung, S. J. Im, and D. H. Yoon, “Photoluminescence characteristics of energy transfer between Bi3+ and Eu3+ in LnVO4: Eu, Bi (Ln = Y, La, Gd),” Colloids Surf. A: Physicochem. Eng. Aspects, 313-314, 373–377 (2008).
[21] Y. Wang, Y. Sun, J. Zhang, Z. Ci, Z. Zhang, and L. Wang, “New red Y0.85Bi0.1Eu0.05V1-yMyO4 (M = Nb, P) phosphors for light-emitting diodes,” Physica B, 403, 2071–2075 (2008).
[22] W. J. Park, M. K. Jung, T. Masaki, S. J. Im, and D. H. Yoon, “Characterization of YVO4:Eu3+, Sm3+ red phosphor quick synthesized by microwave rapid heating method,” Mater. Sci. Eng. B, 146, 95–98 (2008).
[23] X. Fu, S. Niu, H. Zhang, and Q. Xin, “Photoluminescence properties of nanocrystalline A3(VO4)2:Eu (A = Mg, Ca, Sr and Ba),” Spectroscopy and Spectral Analysis, 26, 27–29 (2006).
[24] H. Zhang, M. Lü, Z. Xiu, S. Wang, G. Zhou, Y. Zhou, S. Wang, Z. Qiu, and A. Zhang, “Synthesis and photoluminescence properties of a new red emitting phosphor: Ca3(VO4)2:Eu3+;Mn2+,” Mater. Res. Bull., 42, 1145–1152 (2007).
[25] T. Nakajima, M. Isobe, T. Tsuchiya, Y. Ueda, and T. Manabe, “Correlation between luminescence quantum efficiency and structural properties of vanadate phosphors with chained, dimerized, and isolated VO4 tetrahedra,” J. Phys. Chem. C, 114, 5160–5167 (2010).
[26] K. H. Qiu, J. F. Li, J. F. Li, X. G. Lu, Y. C. Gong, and J. H. Li, “Luminescence property of Ca3(VO4)2:Eu3+ dependence on molar ratio of Ca/V and solution combustion synthesis temperature,” J. Mater. Sci., 45, 5456–5462 (2010).
[27] V. D. Zhuravlev, A. A. Fotiev, and B. V. Shulgin, “Thermal and luminescent properties of samples of the systems Ca3(VO4)2 - M3(VO4)2, where M equals Sr, Ba.,” Izv. Akad. Nauk SSSR Neorg. Mater., 15, 2003–2006 (1979).
[28] H. Y. Lin, Y. C. Fang, X. R. Huang, and S. Y. Chu, “Luminescence and site symmetry studies of new red phosphors (Ca, Ba)3(VO4)2: Eu3+ under blue excitation,” J. Am. Ceram. Soc., 93, 138–141 (2010).
[29] B. Valeur, Molecular Fluorescence: Principles and Applications, Wiley-VCH Verlag GmbH, Weinheim, Germany (2002).
[30] J. García Solé, L. E. Bausá, and D. Jaque, An Introduction to the Optical Spectroscopy of Inorganic Solids, John Wiley & Sons Ltd, Spain (2005).
[31] H. Y. Lin and S. Y. Chu, “Concentration dependence of multipolar mechanisms responsible for Sm3+ → Eu3+ energy transfer in (Ca0.97-3x/5.64Sr0.03)2.82(VO4)2:0.12Eu3+,xSm3+ phosphors,” ECS J. Solid State Sci. Technol., 2, R121–R125 (2013).
[32] H. Y. Lin, W. F. Chang, and S. Y. Chu, “Potential phosphors for organic solar cells utilizing Sm3+ as sensitizer: cross-relaxation effect and concentration quenching mechanism,” Optics & Photonics Taiwan, International Conference 2012, OI-SA-MD2-(6)-1, National Taiwan University, Taipei, Taiwan, Dec. 6-8 (2012).
[33] T. W. Kuo, C. H. Huang, and T. M. Chen, “Novel yellowish-orange Sr8Al12O24S2:Eu2+ phosphor for application in blue light-emitting diode based white LED,” Opt. Express, 18, A231–A236 (2010).
[34] H. Y. D. Ke and E. R. Birnbaum, “Many-body nonradiative energy transfer in a crystalline europium (III) EDTA complex,” J. Lumin., 63, 9–17 (1995).
[35] D. L. Dexter, “A theory of sensitized luminescence in solids,” J. Chem. Phys., 21, 836–850 (1953).
[36] F. K. Fong and D. J. Diestler, “Many-body processes in nonradiative energy transfer between ions in crystals,” J. Chem. Phys., 56, 2875–2880 (1972).
[37] H. Y. Lin, Y. C. Fang, and S. Y. Chu, “Energy transfer Sm3+→Eu3+ in potential red phosphor (Ca, Ba)3(VO4)2:Sm3+, Eu3+ for use in organic solar cells and white light-emitting diodes,” J. Am. Ceram. Soc., 93, 3850–3856 (2010).
[38] H. Jiao, F. H. Liao, S. J. Tian, and X. P. Jing, “Luminescent properties of Eu3+ and Tb3+ activated Zn3Ta2O8,” J. Electrochem. Soc., 150, H220–H224 (2003).
[39] G. Tripathi, V. K. Rai, and S. B. Rai, “Spectroscopic studies of Eu3+ doped calibo glass: effect of the addition of barium carbonate, energy transfer in the presence of Sm3+,” Opt. Commun., 264, 116–122 (2006).
[40] L. Wu, Y. Zhang, M. Y. Gui, P. Z. Lu, L. X. Zhao, S. Tian, Y. F. Kong, and J. J. Xu, “Luminescence and energy transfer of a color tunable phosphor: Dy3+-, Tm3+-, and Eu3+-coactivated KSr4(BO3)3 for warm white UV LEDs,” J. Mater. Chem., 22, 6463–6470 (2012).
[41] Y. C. Chiu, W. R. Liu, Y. T. Yeh, S. M. Jang, and T. M. Chen, “Luminescent properties and energy transfer of green-emitting Ca3Y2(Si3O9)2:Ce3+,Tb3+ phosphor,” J. Electrochem. Soc., 156, J221–J225 (2009).
[42] W. J. Yang and T. M. Chen, “White-light generation and energy transfer in SrZn2(PO4)2:Eu,Mn phosphor for ultraviolet light-emitting diodes,” Appl. Phys. Lett., 88, 101903, 3pp (2006).
[43] W. Xu, Q. W. Peng, J. H. Dong, Y. Gao, X. L. Liang, S. F. Wang, and G. R. Chen, “Photoluminescence properties and energy transfer of Dy3+-Eu3+ codoped phosphate glasses,” J. Am. Ceram. Soc., 93, 3064–3067 (2010).
[44] X. Y. Bao, S. P. Zhou, J. G. Wang, L. J. Zhang, S. M. Huang, and Y. X. Pan, “Color tunable phosphor CaMoO4:Eu3+,Li+ via energy transfer of MoO42−-Eu3+ dependent on morphology and doping concentration,” Mater. Res. Bull., 48, 1034–1039 (2013).
[45] H. Y. Chung, C. H. Lu, and C. H. Hsu, “Preparation and photoluminescence properties of novel color-tunable MgY4Si3O13:Ce3+, Tb3+ phosphors for ultraviolet light-emitting diodes,” J. Am. Ceram. Soc., 93, 1838–1841 (2010).
[46] T. W. Kuo and T. M. Chen, “A green-emitting phosphor Sr3La(PO4)3: Ce3+,Tb3+  with efficient energy transfer for fluorescent lamp,” J. Electrochem. Soc., 157, J216–J220 (2010).
[47] W. J. Yang and T. M. Chen, “Ce3+/Eu2+ codoped Ba2ZnS3: a blue radiation-converting phosphor for white light-emitting diodes,” Appl. Phys. Lett., 90, 171908, 3pp (2007).
[48] H. Y. Lin and S. Y. Chu, “Down-shifting and up-conversion spectroscopic properties of (Ca,Mg)3(VO4)2:Yb3+,Eu3+ phosphors,” J. Am. Ceram. Soc., 95, 3538–3546 (2012).
[49] J. Y. Sun, J. H. Zeng, Y. I. Sun, and H. Y. Du, “Photoluminescence properties and energy transfer of Ce3+, Eu2+ co-doped Sr3Gd(PO4)3 phosphor,” J. Alloys Compd., 540, 81–84 (2012).
[50] L. G. Van Uitert, “Characterization of energy transfer interactions between rare earth ions,” J. Electrochem. Soc., 114, 1048–1053 (1967).
[51] X. H. Dou, W. R. Zhao, E. H. Song, G. X. Zhou, C. Y. Yi, and M. K. Zhou, “Photoluminescence characterization of Ca10Na(PO4)7:Eu3+ red-emitting phosphor,” Spectroc. Acta Pt. A: Molec. Biomolec. Spectr., 78, 821–825 (2011).
[52] A. Beiser, Concepts of Modern Physics, McGraw-Hill, New York, America (2003).
[53] H. Y. Lin, “The syntheses and optical investigations of new phosphors: calcium vanadates codoped with alkaline earth and rare earth ions,” Thesis for Master of Science, National Cheng Kung University, Tainan, Taiwan (2009).
[54] A. Shalav, B. S. Richards, and M. A. Green, “Luminescent layers for enhanced silicon solar cell performance: up-conversion,” Sol. Energy Mater. Sol. Cells, 91, 829–842 (2007).
[55] Y. C. Fang, X. R. Huang, H. Y. Lin, and S. Y. Chu, “Energy transfer mechanism and luminescence of Ce0.67Tb0.33Mg1-xMnxAl11O19 wide-color-gamut CCFL green phosphor,” J. Am. Ceram. Soc., 94, 2735–2738 (2011).
[56] Z. G. Chen, L. S. Zhang, Y. G. Sun, J. Q. Hu, and D. Y. Wang, “980-nm laser-driven photovoltaic cells based on rare-earth up-converting phosphors for biomedical applications,” Adv. Funct. Mater., 19, 3815–3820 (2009).
[57] S. Sivakumar and F. C. J. M. van Veggel, “Red, green, and blue light through cooperative up-conversion in sol-gel thin films made with Yb0.80La0.15Tb0.05F3 and Yb0.80La0.15Eu0.05F3 nanoparticles,” IEEE J. Disp. Technol., 3, 176–183 (2007).
[58] R. Martín-Rodríguez, R. Valiente, S. Polizzi, M. Bettinelli, A. Speghini, and F. Piccinelli, “Upconversion luminescence in nanocrystals of Gd3Ga5O12 and Y3Al5O12 doped with Tb3+-Yb3+and Eu3+-Yb3+,” J. Phys. Chem. C, 113, 12195–12200 (2009).
[59] L. L. Wang, X. J. Xue, F. Shi, D. Zhao, D. S. Zhang, K. Z. Zheng, G. F. Wang, C. F. He, R. J. Kim, and W. P. Qin, “Ultraviolet and violet upconversion fluorescence of europium (III) doped in YF3 nanocrystals,” Opt. Lett., 34, 2781–2783 (2009).
[60] P. de Sousa Filho and O. Serra, “Reverse microemulsion synthesis, structure, and luminescence of nanosized REPO4:Ln3+ (RE = La, Y, Gd, or Yb, and Ln = Eu, Tm, or Er),” J. Phys. Chem. C, 115, 636–646 (2011).
[61] G. Mialon, S. Türkcan, G. Dantelle, D. P. Collins, M. Hadjipanayi, R. A. Taylor, T. Gacoin, A. Alexandrou, and J. P. Boilot, “High up-conversion efficiency of YVO4:Yb,Er nanoparticles in water down to the single-particle level,” J. Phys. Chem. C, 114, 22449–22454 (2010).
[62] W. Xiong, P. Z. Yang, J. Y. Liao, and S. K. Lin, “Growth and spectral properties of Yb3+ /Ho3+ co-doped Gd0.9La0.1VO4 crystal,” J. Cryst. Growth, 280, 212–216 (2005).
[63] W. Ryba-Romanowski, P. Solarz, G. Dominiak-Dzik, R. Lisiecki, and T. Łukasiewicz, “Relaxation of excited states and up-conversion phenomena in rare earth-doped YVO4 crystals grown by the cznchralski method,” Laser Phys.,14, 250–257 (2004).
[64] W. Liu, Y. G. Wang, and L. F. Cheng, “Eu3+-doped YPO4 self-monitoring environmental barrier coating,” J. Am. Ceram. Soc., 94, 3449–3454 (2011).
[65] C. H. Hsu, B. M. Cheng, and C. H. Lu, “Photoluminescent properties and energy transfer mechanism of color-tunable CaSi2O2N2:Ce3+, Eu2+ phosphors,” J. Am. Ceram. Soc., 94, 2878–2883 (2011).
[66] M. D. Chambers and D. R. Clarke, “Doped oxides for high-temperature luminescence and lifetime thermometry,” Annu. Rev. Mater. Res., 39, 325–359 (2009).
[67] M. Leroux, N. Grandjean, B. Beaumont, G. Nataf, F. Semond, J. Massies, and P. Gibart, “Temperature quenching of photoluminescence intensities in undoped and doped GaN,” J. Appl. Phys., 86, 3721–3728 (1999).
[68] H. S. Wang, C. K. Duan, and P. A. Tanner, “Visible upconversion luminescence from Y2O3:Eu3+,Yb3+,” J. Phys. Chem. C, 112, 16651–16654 (2008).
[69] E. Nakazawa and S. Shionoya, “Cooperative luminescence in YbVO4,” Phys. Rev. Lett., 25, 1710–1712 (1970).
[70] M. Pollnau, D. R. Gamelin, S. R. Lüthi, H. U. Güdel, and M. P. Hehlen, “Power dependence of upconversion luminescence in lanthanide and transition-metal-ion systems,” Phys. Rev. B, 61, 3337–3346 (2000).
[71] G. S. Maciel, A. Biswas, and P. N. Prasad, “Infrared-to-visible Eu3+ energy upconversion due to cooperative energy transfer from an Yb3+ ion pair in a sol-gel processed multi-component silica glass,” Opt. Commun., 178, 65–69 (2000).
[72] A. Wasiela, D. Block, and Y. Merle d’Aubigné, “Chromium-gallium complexes in Al2O3 II. energy transfer *,” J. Lumin., 36, 23–37 (1986).
[73] O. Barbosa-García, L. A. Díaz-Torres, M. A. Meneses-Nava, J. F. Mosiño, and J. T. Vega-Durán, “Energy back-transfer and other nonradiative energy-transfer processes in Yb3+, Er3+: Y3Al5O12,” J. Electrochem. Soc., 149, J31–J34 (2002).
[74] G. Blasse, “Energy transfer in oxidic phosphors,” Philips Res. Rep., 24, 131–144 (1969).
[75] K. Mori, H. Nishimura, M. Nakayama, H. Ishibashi, “Dynamical aspects of the core excitons formed by the 4f–4f transitions of Gd3+ in Gd2SiO5,” J. Lumin., 87-89, 266–268 (2000).
[76] X. L. Liang, Z. Y. Lin, Y. X. Yang, Z. W. Xing, and G. R. Chen, “Luminescence properties of Tb–Eu co-doped aluminosilicate and zinc silicate glasses,” J. Am. Ceram. Soc., 95, 275–279 (2012).
[77] P. Solarz, “Pr3+ as a sensitiser of red Eu3+ luminescence in K5Li2GdF10:Pr3+, Eu3+ upon VUV–UV excitation,” Opt. Mater., 31, 114–116 (2008).
[78] G. A. Kumar, R. E. Riman, L. A. Diaz Torres, S. Banerjee, M. D. Romanelli, T. J. Emge, and J. G. Brennan, “Near-infrared optical characteristics of chalcogenide-bound Nd3+ molecules and clusters,” Chem. Mater., 19, 2937–2946 (2007).
[79] K. K. Mahato, D. K. Rai, and S. B. Rai, “Optical studies of Sm3+ doped oxyfluoroborate glass, ” Solid State Commun., 108, 671–676 (1998).
[80] X. M. Zhang, J. H. Zhang, J. Xu, and Q. Su, “Luminescent properties of Eu2+-activated SrLaGa3S6O phosphor,” J. Alloys Compd., 389, 247–251 (2005).
[81] R. Faoro, F. Moglia, M. Tonelli, N. Magnani, and E. Cavalli, “Energy levels and emission parameters of the Dy3+ ion doped into the YPO4 host lattice,” J. Phys.: Condens. Matter, 21, 275501, 7pp (2009).
[82] E. Cavalli, E. Bovero, and A. Belletti, “Optical spectroscopy of CaMoO4:Dy3+ single crystals,” J. Phys.: Condens. Matter, 14, 5221–5228 (2002).
[83] K. K. Mahato, A. Rai, and S. B. Rai, “Optical properties of Dy3+ doped in oxyfluoroborate glass,” Spectroc. Acta Pt. A: Molec. Biomolec. Spectr., 61, 431–436 (2005).
[84] I. R. Martín, J. Méndez-Ramos, F. Delgado, V. Lavín, U. R. Rodríguez-Mendoza, V. D. Rodríguez, and A. C. Yanes, “Energy transfer between Eu3+ ions in sol–gel derived silica glasses,” J. Alloys Compd., 323-324, 773–777 (2001).
[85] V. Lavín, I. R. Martín, U. R. Rodríguez-Mendoza, and V. D. Rodríguez, “Energy transfer between Eu3+ ions in calcium diborate glasses,” J. Phys.: Condens. Matter, 11, 8739–8747 (1999).
[86] K. K. Mahato and S. B. Rai, “Laser spectroscopic studies of Tb3+-doped oxyfluoroborate glass,” Spectroc. Acta Pt. A: Molec. Biomolec. Spectr., 56, 2333–2340 (2000).
[87] X. X. Ju, X. M. Li, W. L. Li, W. J. Yang, and C. Y. Tao, “Luminescence properties of ZnMoO4:Tb3+ green phosphor prepared via co-precipitation,” Mater. Lett., 65, 2642–2644 (2011).
[88] R. Wang, J. Xu, and C. Chen, “Luminescent characteristics of Sr2B2O5: Tb3+, Li+ green phosphor,” Mater. Lett., 68, 307–309 (2012).
[89] H. Y. Lin, W. F. Chang, and S. Y. Chu, “Luminescence of (Ca,Sr)3(VO4)2:Pr3+,Eu3+ phosphor for use in CuPc-based solar cells and white light-emitting diodes,” J. Lumin., 133, 194–199 (2013).
[90] Y. J. Huang, H. P. You, G. Jia, Y. H. Zheng, Y. H. Song, M. Yang, K. Liu, and L. H. Zhang, “Hydrothermal synthesis and luminescence of Eu-doped Ba0.92Y2.15F8.29 submicrospheres,” J. Phys. Chem. C, 113, 16962–16968 (2009).
[91] X. S. Qu, H. K. Yang, B. K. Moon, B. C. Choi, J. H. Jeong, and K. H. Kim, “Preparation and photoluminescence properties of Gd2O3:Eu3+ inverse opal photonic crystals,” J. Phys. Chem. C, 114, 19891–19894 (2010).
[92] Y. C. Chang, C. H. Liang, S. A. Yan, and Y. S. Chang, “Synthesis and photoluminescence characteristics of high color purity and brightness Li3Ba2Gd3(MoO4)8:Eu3+ red phosphors,” J. Phys. Chem. C, 114, 3645–3652 (2010).
[93] S. Cotton, Lanthanide and Actinide Chemistry, John Wiley & Sons Ltd, Chichester, UK (2006).
[94] X. Y. Yang, J. Liu, H. Yang, X. B. Yu, Y. Z. Guo, Y. Q. Zhou, and J. Y. Liu, “Synthesis and characterization of new red phosphors for white LED applications,” J. Mater. Chem., 19, 3771–3774 (2009).
[95] Y. Q. Zhou, J. Liu, X. Y. Yang, X. B. Yu, and J. Zhuang, “A promising deep red phosphor AgLaMo2O8 : Pr3+ with blue excitation for white LED application,” J. Electrochem. Soc., 157, H278–H280 (2010).
[96] D. Logvinovich, A. Arakcheeva, P. Pattison, S. Eliseeva, P. Tomeš, I. Marozau, and G. Chapuis, “Crystal structure and optical and magnetic properties of Pr2(MoO4)3,” Inorg. Chem., 49, 1587–1594 (2010).
[97] X. K. Wu, W. M. Dennis, and W. M. Yen, “Temperature dependence of cross-relaxation processes in Pr3+-doped yttrium aluminum garnet,” Phys. Rev. B, 50, 6589–6595 (1994).
[98] M. Inokuti and F. Hirayama, “Influence of energy transfer by the exchange mechanism on donor luminescence,” J. Chem. Phys., 43, 1978–1989 (1965).
[99] A. Belarouci, F. Menchini, B. Jacquier, P. Moretti, H. Rigneault, and S. Robert, “Luminescence properties of Pr3+-doped optical microcavities,” J. Lumin., 83-84, 275–282 (1999).
[100] Y. C. Fang, S. Y. Chu, P. C. Kao, Y. M. Chuang, and Z. L. Zeng, “Energy transfer and thermal quenching behaviors of CaLa2(MoO4)4:Sm3+,Eu3+ red phosphors,” J. Electrochem. Soc., 158, J1–J5 (2011).
[101] S. Okamoto and H. Yamamoto, “Photoluminescent properties of (La,Eu,Sm)2W3O12 red phosphor for near-UV-LED-based solid-state lighting,” Electrochem. Solid-State Lett., 10, J139–J142 (2007).
[102] Y. H. Won, H. S. Jang, W. B. Im, and D. Y. Jeon, “Red-emitting LiLa2O2BO3:Sm3+,Eu3+ phosphor for near-ultraviolet light-emitting diodes-based solid-state lighting,” J. Electrochem. Soc., 155, J226–J229 (2008).
[103] G. H. Lee, T. H. Kim, C. Yoon, and S. Kang, “Effect of local environment and Sm3+-codoping on the luminescence properties in the Eu3+-doped potassium tungstate phosphor for white LEDS,” J. Lumin., 128, 1922–1926 (2008).
[104] H. Lin, D. Yang, G. Liu, T. Ma, B. Zhai, Q. An, J. Yu, X. Wang, X. Liu, and E. Y. B. Pun, “Optical absorption and photoluminescence in Sm3+- and Eu3+-doped rare-earth borate glasses,” J. Lumin., 113, 121–128 (2005).
[105] H. Lin, E. Y. B. Pun, X. Wang, and X. Liu, “Intense visible fluorescence and energy transfer in Dy3+, Tb3+, Sm3+ and Eu3+ doped rare-earth borate glasses,” J. Alloys Compd., 390, 197–201 (2005).
[106] Y. Yu, Y. Liu, and M. Song, “Luminescence and energy transfer in GdP5O14:Eu3+,Sm3+ single crystals,” J. Alloys Compd., 202, 47–50 (1993).
[107] R. Reisfeld and L. Boehm, “Energy transfer between samarium and europium in phosphate glasses,” J. Solid State Chem., 4, 417–424 (1972).
[108] P. R. Biju, G. Jose, V. Thomas, V. P. N. Nampoori, and N. V. Unnikrishnan, “Energy transfer in Sm3+:Eu3+ system in zinc sodium phosphate glasses,” Opt. Mater., 24, 671–677 (2004).
[109] Y. Jin, Z. D. Hao, X. Zhang, Y. S. Luo, X. J. Wang, and J. H. Zhang, “Dynamical processes of energy transfer in red emitting phosphor CaMoO4:Sm3+, Eu3+,” Opt. Mater., 33, 1591–1594 (2011).
[110] J. H. Zhang, L. Wang, Y. Jin, X. Zhang, Z. D. Hao, and X. J. Wang, “Energy transfer in Y3Al5O12:Ce3+, Pr3+ and CaMoO4:Sm3+, Eu3+ phosphors,” J. Lumin., 131, 429–432 (2011).
[111] D. Kouyate, J. C. Ronfard-Haret, and J. Kossanyi, “Electroluminescence of rare earths-doped semiconducting zinc oxide electrodes: kinetic aspects of the energy transfer between Sm3+ and Eu3+,” J. Lumin., 55, 209–216 (1993).
[112] G. Ajithkumar, P. K. Gupta, G. Jose, and N. V. Unnikrishnan, “Judd-Ofelt intensity parameters and laser analysis of Pr3+ doped phosphate glasses sensitized by Mn2+ ions,” J. Non-Cryst. Solids, 275, 93–106 (2000).
[113] H. Y. Lin, H. N. Chen, T. H. Wu, C. S. Wu, Y. K. Su, and S. Y. Chu, “Investigation of green up-conversion behavior in Y6W2O15:Yb3+,Er3+ phosphor and its verification in 973-nm laser-driven GaAs solar cell,” J. Am. Ceram. Soc., 95, 3172–3179 (2012).
[114] A. P. Vink, M. A. Reijme, and A. Meijerink, “Line broadening studies for isoelectronic divalent and trivalent lanthanides,” J. Lumin., 92, 189–197 (2001).
[115] M. Tanaka and T. Kushida, “Optical transition mechanisms of Sm2+ and Eu3+ in solids,” J. Lumin., 72-74, 141–143 (1997).
[116] C. Kulshreshtha, S. H. Cho, Y. S. Jung, and K. S. Sohn, “Deep red color emission in an Sm2+-doped SrB4O7 phosphor,” J. Electrochem. Soc., 154, J86–J90 (2007).
[117] D. K. G. de Boer, D. J. Broer, M. G. Debije, W. Keur, A. Meijerink, C. R. Ronda, and P. P. C. Verbunt, “Progress in phosphors and filters for luminescent solar concentrators,” Opt. Express, 20, A395–A405 (2012).
[118] Z. W. Pei, Q. Su, and J. Y. Zhang, “The valence change from RE3+ to RE2+ (RE≡Eu, Sm, Yb) in SrB4O7: RE prepared in air and the spectral properties of RE2+,” J. Alloys Compd., 198, 51–53 (1993).
[119] Q. H. Zeng, Z. W. Pei, S. B. Wang, Q. Su, and S. Z. Lu, “The luminescent properties of Sm2+ in strontium tetraborates (SrB4O7 : Sm2+),” J. Phys. Chem. Solids, 60, 515–520 (1999).
[120] H. B. Liang, Q. H. Zeng, T. D. Hu, S. B. Wang, and Q. Su, “Local structure and valences of samarium in SrB4O7:Sm and SrB6O10:Sm prepared in air,” Solid State Sci., 5, 465–467 (2003).
[121] K. W. Jang, I. G. Kim, S. T. Park, Y. L. Huang, H. J. Seo, and C. D. Kim, “Reduction effect on the optical properties of Sm2+ doped in SrB4O7 and SrB6O10 crystals,” J. Phys. Chem. Solids, 67, 2316–2321 (2006).
[122] Q. H. Zeng, Z. W. Pei, Q. Su, and S. Z. Lu, “Luminescence properties of Sm2+ in barium octaborates (BaB8O13 : Sm2+),” J. Lumin., 82, 241–249 (1999).
[123] Q. H. Zeng, N. T. Kilah, and M. Riley, “The luminescence of Sm2+ in alkaline earth borophosphates,” J. Lumin., 101, 167–174 (2003).
[124] J. Y. Wang, Y. L. Huang, Y. D. Li, and H. J. Seo, “The reduction and luminescence characteristics of Sm2+ doped in Ba3BP3O12 crystal,” J. Am. Ceram. Soc., 94, 1454–1459 (2011).
[125] M. Y. Peng, Z. W. Pei, G. Y. Hong, and Q. Su, “Study on the reduction of Eu3+ → Eu2+ in Sr4Al14O25:Eu prepared in air atmosphere,” Chem. Phys. Lett., 371, 1–6 (2003).
[126] S. Takeshita, K. Nakayama, T. Isobe, T. Sawayama, and S. Niikura, “Optical properties of transparent wavelength-conversion film prepared from YVO4:Bi3+,Eu3+ nanophosphors,” J. Electrochem. Soc., 156, J273–J277 (2009).
[127] H. Y. Lin and S. Y. Chu, “Hydrothermal syntheses and luminescence of nano-sized YVO4:Eu3+ phosphor gel,” Nanometer-Scale Technology and Materials Symposium 2011, p7-3, Da-Yeh University, Changhua, Taiwan, Dec. 16 (2011).