PDP Application Research Articles

Quantum efficiency of europium doped LaPO4 phosphors for UV sensing applications

The radiation conversion phenomenon is used for UV sensing applications with rare earth doped phosphors. This paper presents the results of structural and optical measurements of undoped and europium doped LaPO4 phosphors. LaPO4 phosphors with 1% mol, 2% mol, and 5% mol of europium were fabricated by the co-precipitation method. The effect of Eu3+ concentrations on the luminescence characteristics under UV LED excitation was investigated. The maximum quantum efficiency of luminescence (c.a. 82%) was obtained in sampled doped with 5% of europium. Full Text: PDF ReferencesM. Runowski, "Nanotechnologia – nanomateriały, nanocząstki i wielofunkcyjne nanostruktury typu rdzeń/powłoka", Chemik 68, 9, 766-775 (2014). DirectLink J. Zhou, J.L. Leano Jr., Z. Liu, D. Jin, K.-L. Wong, R.S. Liu, et al., "Impact of Lanthanide Nanomaterials on Photonic Devices and Smart Applications", Small 14, 1801882 (2018). CrossRef Z. Li, Y. Zhang, G. Han, "Lanthanide-Doped Upconversion Nanoparticles for Imaging-Guided Drug Delivery and Therapy", Springer Series in Biomater. Sci. Eng. 6, 139-164, (2016). CrossRef M. Lin, Y. Zhao, S. Wang, M. Liu, Z. Duan, Y. Chen, et al., "Recent advances in synthesis and surface modification of lanthanide-doped upconversion nanoparticles for biomedical applications", Biotechnol. Adv. 30, 1551-1561 (2012). CrossRef H. Su, Y. Nie, H. Yang, D. Tang, K. Chen, T. Zhang, "Improving the thermal stability of phosphor in a white light-emitting diode (LED) by glass-ceramics: Effect of Al2O3 dopant", J. Eur. Ceram. Soc. 38, 2005-2009 (2018). CrossRef J. Huang, X. Hu, J. Shen, D. Wu, C. Yin, R. Xiang, et al., "Facile synthesis of a thermally stable Ce3+:Y3Al5O12 phosphor-in-glass for white LEDs", Cryst. Eng. Comm 17, 7079-7085 (2015). CrossRef R. Zhang, H. Lin, Y. Yu, D. Chen, J. Xu, Y. Wang, "A new-generation color converter for high-power white LED: transparent Ce3+:YAG phosphor-in-glass", Laser Photon. Rev. 8, 158-164 (2014). CrossRef B. Zheng, Y. Bai, H. Chen, H. Pan, W. Ji, X. Gong, et al., "Near-Infrared Light-Excited Upconverting Persistent Nanophosphors in Vivo for Imaging-Guided Cell Therapy", ACS Appl. Mater. Interfaces 10, 19514 (2018). CrossRef J. Qiao, G. Zhou, Y. Zhou, Q. Zhang, Z. Xia, "Divalent europium-doped near-infrared-emitting phosphor for light-emitting diodes", Nature Communications 10 (1), 5267 (2019). CrossRef V. Singh, A. Kumar, C. Mehare, H. Jeong, S. Dhoble, "UV/VUV excited photoluminescence of Tb3+ doped LaPO4 green emitting phosphors for PDP applications", Optik 206, 163733 (2020). CrossRef G. Han, Y. Wang, C. Wu, J. Zhang, "Hydrothermal synthesis and vacuum ultraviolet-excited luminescence properties of novel Dy3+-doped LaPO4 white light phosphors", Mat. Res. Bull. 44 (12), 2255-2257 (2009). CrossRef K. S. Gupta, P. S. Ghosh, M. Sahu, K. Bhattacharyya, R. Tewari, V. Natarajan, "Intense red emitting monoclinic LaPO4:Eu3+ nanoparticles: host–dopant energy transfer dynamics and photoluminescence properties", RSC Adv. 5, 58832-58842 (2015). CrossRef

Investigation of UV and VUV excited photoluminescence features of green-emitting YPO4 doped with Tb3+ phosphors

In this study, Tb3+-activated YPO4 phosphor powders were prepared via co-precipitation method. Samples were identified by powder X-ray diffraction (PXRD), which revealed the structural and crystalline features. Fourier transform-infrared spectroscopy (FT-IR) was used to determine the presence of IR-active functional groups in the prepared samples. Prepared phosphor showed sharp green emission under UV and VUV excitation having excitation wavelengths of 147 nm, 172 nm, and 224 nm. The color-correlated temperature of the phosphor suggested a cool greenish light. Therefore, the prepared luminescent powder has potential applications in white light-emitting diodes converted from green phosphors, optical display setups and PDP applications.

Photoluminescence features of green-emitting sol-gel synthesized La2W3O12 doped with Tb3+ phosphor for PDP applications

The La2-xW3O12:xTb (0.005 ≤ x ≤ 0.10) phosphors were synthesized by a sol-gel process. The structural characterization was carried out using powder X-ray diffraction (PXRD) and Fourier transform infrared spectra (FTIR) techniques. The crystallite size was estimated by Scherrer formula and it is found to be in the range of 45−56 nm. The excitation spectra for all the prepared phosphors were recorded under monitoring at 544 nm. The emission spectra recorded for different excitation wavelengths (274, 147 and 172 nm) show all the characteristic emissions of Tb3+ ions. Thus, the prepared phosphors are suitable for application in plasma display panels.

UV/VUV excited photoluminescence of Tb3+ doped LaPO4 green emitting phosphors for PDP applications

La1-xPO4:xTb (x = 0.01 ≤ x ≤ 0.11) phosphors were synthesized using conventional co-precipitation method. The powder X-ray diffraction confirmed the pure phase formation of LaPO4 host material. Upon ultra-violet (UV) excitation and vacuum ultra-violet (VUV), the phosphor showed a dominant green emission band centered at 544 and 545 nm, respectively due to the 5D4→7F5 transition of Tb3+. The concentration quenching phenomena occurred when Tb3+ concentration was beyond 0.09 mol and this quenching mechanism could be explained by the dipole-dipole interaction. The optimal concentration was found to be 0.09 mol of Tb3+ ion. The CIE chromaticity coordinates of the optimized (La0.91PO4:0.09Tb) phosphor was determined to be (0.265, 0.567). All the analyzed results confirms that the La1-xPO4:xTb (x = 0.01 ≤ x ≤ 0.11) phosphors can find possible applications as promising green-emitting phosphor in near UV and VUV used in plasma display panels.

Discharge Simulation and Fabrication Process of an Aluminum Electrode and an Alumina Layer in AC-PDP

A larger space PDP cell with patterned aluminum as the addressing electrode and alumina as the dielectric layer was proposed. The aluminum electrode and the alumina dielectric layer formed on the aluminum electrode were prepared separately by magnetron sputtering and anodic oxidation for plasma display panel. The properties of the aluminum electrode and the alumina dielectric layer were tested and can meet the demand of PDP application. The resistivity of the aluminum electrode is about 5 × 10−8 Ω·m, the voltage withstanding of the alumina dielectric layer exceeds 100 V/μm and the relative permittivity is about 3.5 at 1 MHz. With this structure, the manufacturing cost of PDP could be cut and the addressing discharge formative delay is reduced by 0.67%, which is proved by PIC-MCC simulation.

The <i>h</i>-BN Protective Method Used for the Synthesis of Highly Uniform Spherical Si-Based Oxynitride Phosphors

The highly uniform spherical Si-based oxynitride core-shell structured phosphors with narrow size distribution and non-aggregation were successfully fabricated by the h-BN protective method for the first time. Firstly, the raw metallic ions (rare earth and alkaline earth ions) were coated on the surface of SiO2 templates via the urea homogeneous precipitation method. Then the core-shell precursor particles were coated with a H3BO3 layer, which was transformed to a h-BN protective film in the reduction condition. At last, the spherical core-shell structured oxynitride phosphors were synthesized through a gas reduction and nitridation method. The as-received phosphors show excellent luminescence properties due to the 4f65d-4f7 transition of Eu2+ under the excitation of UV and blue lights. The homogeneous spherical phosphors are expected to have excellent dispersing and coating properties, which are very important for LED and PDP applications.

PDP用发光材料的研究进展

At present,the commercial tri-color phosphors for PDP application are(Y,Gd)BO3∶ Eu3+(red phosphor),Zn2SiO4∶Mn2+,BaAl12O19∶Mn2+ or(Gd,Y)BO3∶Tb3+(green phosphors) and BaMgAl10O17∶Eu2+(blue phosphor).However,there exists a common problem in the above tri-color phosphors,that is,their luminescence efficiency is low.Moreover,they also present the disadvantages as follows which restrict their luminescence properties: the color purity of(Y,Gd)BO3∶Eu3+ is poor;the decay lifetimes of Zn2SiO4∶Mn2+ and BaAl12O19∶Mn2+ are long;the luminescence intensity of(Gd,Y)BO3∶Tb3+ is insufficiency,while BaMgAl10O17∶Eu2+ presents poor stability when treated by heating or VUV irradiation.Aiming at these problems,this paper summarizes the recent research progresses on the VUV luminescence mechanism and the improvement of luminescence properties for the tri-color phosphors.Meanwhile,the research progress on the exploring of novel VUV phosphors is also involved.

Photoluminescence of Tb 3+ and Mn 2+ activated Ca 8MgGd(PO 4) 7 under vacuum ultraviolet excitation

Novel Tb 3+ and Mn 2+ activated Ca 8MgGd(PO 4) 7 phosphors were synthesized by solid-state reaction and their photoluminescence properties in vacuum ultraviolet region were investigated for the first time. It can be observed from the excitation spectra that the host-related absorption band is located around 170 nm, and it overlaps the O 2− → Tb 3+ charge transfer band of Ca 8MgGd(PO 4) 7:Tb 3+ around 161 nm and the 3d 5 → 3d 44s transition band of Ca 8MgGd(PO 4) 7:Mn 2+ near 200 nm. The 4f–4f 5d spin-allowed and spin-forbidden transitions of Tb 3+ are verified to be located at 170–250 and 257–271 nm, respectively. Upon 147 nm excitation, the dominant emission peak intensity of the Ca 8MgGd 0.1(PO 4) 7:0.9Tb 3+ phosphor is about 2.7 times stronger than that of the commercial Zn 2SiO 4:Mn 2+ green phosphor, and the brightness of the former with a short decay time of 2.5 ms is about 98% of the latter’s. The Ca 8MgGd(PO 4):Mn 2+ phosphor excited at 147 nm exhibits a deep red emission around 650 nm, which could be attributed to the 4T 1 → 6A 1 transition of Mn 2+, with the CIE index (0.679, 0.321). In a word, the results above indicate that both Tb 3+ and Mn 2+ activated Ca 8MgGd(PO 4) 7 phosphors could be promising for PDP or Hg-free lamp applications.

Hydrothermal Synthesis and Optical Properties of Eu3+-Doped CaSnO3 Nanocrystals

In this paper, CaSnO3:Eu3+ nanocrystals were prepared by hydrothermal synthesis method. The influence of different molar ratio of Ca:Sn on structure of CaSnO3:Eu3+ was investigated by using X-ray powder diffraction (XRD). Well-crystallized and phase-pure CaSnO3:Eu3+ particles of approximately 90 nm in size can be readily obtained at 900 degrees C. Furthermore, photoluminescence characterization of the Eu(3+)-doped CaSnO3 nanocrystals was performed and discussed. The emission peak situated at 618 nm showing prominent and bright red light is due to the 5D0-7F2 electric dipole transition. The excellent luminescence properties make it possible as a good candidate for PDP application.

Enhanced photoluminescence of BaMgAl 10O 17:Eu 2+ nanophosphor for PDP application

BaMgAl 10O 17:Eu 2+ nanorods were synthesized by sol–gel technique, and their luminescent properties were investigated upon the irradiation of vacuum ultraviolet (VUV) light. By introducing surfactant cetyl-tri-methyl-ammonium bromide (CTAB) in sol–gel process and additional Mg 2+ in the raw materials, the emission intensity and thermal stability of the nanophosphor were both enhanced. The above improvements made it possible that the nanosized BAM phosphor could be a good alternative for PDP application.

Enhanced photoluminescence of spray pyrolysis processed YBO 3:Eu 3+ for PDP application

The Y 0.94Eu 0.06BO 3 phosphor powders, which were annealed after synthesizing under three-heating zones, showed more spherical morphology and uniform size in comparison with the phosphors under single-heating zones. The annealed Y 0.94Eu 0.06BO 3 phosphors were single phase with the hexagonal vaterite structure ( a = 3.776 Å and c = 8.806 Å) and the space group P6 3 /m (176). The emission spectra consisted of three strong peaks at 593, 610, and 627 nm. These peaks were caused by transitions from the excited 5D 0 to 7F j ( j = 1 and 2) levels of the Eu 3+ activator. The emission intensity of the Y 0.94Eu 0.06BO 3 phosphors synthesized under a three-heating zone (800, 1000, and 800 °C) was higher than that of the commercial YBO 3:Eu 3+ phosphor. This demonstrates that the three-zone heating in the spray pyrolysis yielded a higher emission intensity.

Red-emitting (Y 0.5Gd 0.5) 0.94−xAl xEu 0.06VO 4 (0 ⩽ x ⩽ 0.04) phosphors for plasma display panel applications

We synthesized high-quality (Y 0.5Gd 0.5) 0.94− x Al x Eu 0.06VO 4 (0 ⩽ x ⩽ 0.04) red phosphors by ultrasonic spray pyrolysis. The annealed (Y 0.5Gd 0.5) 0.94− x Al x Eu 0.06VO 4 (0 ⩽ x ⩽ 0.04) was solid solutions of the constituent oxides, which had a tetragonal zircon type structure. The incorporation of a small amount of Al to (Y 0.5Gd 0.5) 0.94− x Al x Eu 0.06VO 4 up to x = 0.02 significantly enhanced the emission intensity. The (Y 0.5Gd 0.5) 0.92Al 0.02Eu 0.06VO 4 phosphor annealed at 1150 °C emitted the strongest and purest red color. In addition, enhanced photoluminescence properties of (Y 0.5Gd 0.5) 0.94− x Al x Eu 0.06VO 4 red phosphors were obtained over a wide range of annealing temperature (1100–1150 °C), thereby allowing greater flexibility for the choice of their annealing temperature. We demonstrate that the (Y 0.5Gd 0.5) 0.94− x Al x Eu 0.06VO 4 could be a novel red phosphor for PDP applications.

Synthesis of Green Emitting (Mg,Zn)Al2O4:Mn2+ Phosphor and Its VUV Characteristics for PDP Applications

not Available.

New red phosphor (Y, Gd, Lu)BO 3: Eu 3+ for PDP applications

Highly efficient phosphors under vacuum ultraviolet excitation are still demanded for the development of plasma display panels and Hg-free fluorescent lamps. The phosphors of Eu 3+ doped (Y, Gd, Lu)BO 3 were synthesized with solid state reaction method and the contents of Y 3+, Gd 3+, and Lu 3+ for plasma display panel red phosphor were optimized under vacuum ultraviolet excitation. Two new potential candidates, which were (Y 1– S– T Gd S Lu T )BO 3: Eu 3+ (0< S<0.2, 0< T≤0.1) and (Gd I Y J Lu K )BO 3: Eu 3+ (0.5< I<0.7, 0.2< J<0.4, 0< K≤0.1), were obtained. The mechanism of luminescence improvement was discussed upon the analysis of crystal microstructure and excitation spectra.

Photoluminescence of YVO4:Eu3+Prepared by Li2CO3Addition

Deep red color emitting YVO₄:Eu 3+ phosphors were investigated in an attempt to achieve promising performances in cold cathode fluorescent lamp (CCFL) applications. For this purpose, several additives such as LiF, LiCO₃ and HBO₃ were introduced in the processing. While two of the additives were ineffective, the inclusion of LiCO₃ during the solid state synthesis of YVO₄:Eu 3+ phosphors was proven to enhance photoluminescent intensity and the color chromaticity. Unlike the commercially available Y(V,P)O₄:Eu 3+ red phosphor for use in PDP applications, pure YVO₄:Eu 3+ excluding phosphorous was shown to be favorable for CCFL applications, improving color chromaticity at 254 nm excitations.

Synthesis and luminescent properties of GdSrAl3O7:Tb3+ phosphor under VUV/UV excitation

Abstract Superfine powder of Tb3+ ion-doped aluminates phosphors, GdSrAl3O7:Tb3+ was synthesized with a precursor prepared by an EDTA-sol–gel method at 900 °C. Field-emission scanning electron-microscopy (FE-SEM) observation indicated a narrow size-distribution of about 150–300 nm for the particles with elliptical shape. Upon excitation with vacuum ultraviolet (VUV) and near UV light excitation, the phosphors show a strong emission line at around 542 nm corresponding to the 5D4 → 7F5 transition of Tb3+, and the highest PL intensity at 542 nm was found at a content of about 12 mol% Tb3+. As the Tb3+ concentration increases, Tb ions strongly cross-relaxation interact resulting in a decrease of the lifetime. The results reveal that GdSrAl3O7:Tb3+ would be a promising green phosphor for PDP application.

Combustion Synthesis and Luminescent Properties of blue-emitting Nanocrystalline Phosphor for PDP Application

Combustion Synthesis and Luminescent Properties of blue-emitting Nanocrystalline Phosphor for PDP Application

18.2: Investigation of Micro-Scale Capillary Plasmas for a PDP Application

The properties and characteristics of micro-scale Capillary Plasma Electrode Discharges (CPEDs) were investigated. We examined the basic discharge characteristics of AC-type micro-scale CPEDs as a function of the L/D ratio. Using the basis of the previous findings, we applied the CPED concept to the design of a commercial plasma display panel and compared the discharge characteristics with those of a conventional DBD-based PDP. The optimum parameters for micro-scale CPED are L/D ratio = ∼0.5, diameter (D) = 125 μm, length (L) = 70 μm, total dielectric thickness (T) = 90 μm. The luminous efficiency of the optimized CPED structure is higher than that of DBD structure with same dielectric thickness. However, by comparison with DBD structure with T= 45 μm which is somewhat higher dielectric thickness than current conventional PDP (T= ∼30 μm) but has almost similar discharge characteristic, there is no noticeable difference in the luminous efficiency.

Effect of SiO2 Addition to BaO-ZnO-B2O3 Glass on Dielectric and Thermal Properties for Application to Barrier Ribs of Plasma Display Panels

The effect of SiO2 addition to barium zinc borate (BaO-ZnO-B2O3, BZB) glass on dielectric and thermal expansion properties was investigated. When SiO2 was added to the glass batch to form a SiO2-BaO-ZnO-B2O3 (SBZB) glass, the dielectric constant decreased significantly from 15.5 to 9.9. When SiO2 (quartz) was further added to the SBZB in the form of filler particles to yield ceramic filler-reinforced SBZB microcomposites, the dielectric constant was further decreased. The coefficient of thermal expansion (CTE) of SBZB was slightly lower than the allowable range, while the filler addition to SBZB correspondingly increased CTE to the allowable range. Thus, the addition of SiO2 to BZB glass to form SBZB glass and further addition to SBZB in the form of ceramic filler were shown to be amenable ways to tailor the dielectric constant as well as CTE of the barrier rib glass for the PDP application.

Enhanced PL and VUV absorption of BaZr(BO3)2:Eu3+ by Al3+ incorporation

Abstract— The photoluminescence (PL) and vacuum‐ultraviolet excitation (VUV) properties of BaZr(BO3)2 doped with the Eu3+ activator ion were studied as a new red phosphor for PDP applications. The excitation spectrum shows strong absorption in the VUV region with an absorption band edge at 200 nm. The charge‐transfer excitation band of Eu3+ was enhanced by co‐doping with an Al3+ ion into the BaZr(BO3)2 lattices. The PL spectrum shows the strongest emission at 615 nm, corresponding to the electric dipole 5D0 → 7F2 transition of Eu3+ in BaZr(BO3)2, which results in good red‐color purity.