A high efficiency rare earth-free orange emitting phosphor

Polikarpov, Evgueni; Catalini, David; Padmaperuma, Asanga B.; Das, P.K.; Lemmon, Teresa; Arey, Bruce W.; Fernández, Carlos A.

doi:10.1016/j.optmat.2015.04.013

Cited by 28 publications

(11 citation statements)

References 47 publications

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“…Due to this, the design of rare-earth free materials is majorly needed. The rare-earth free phosphors can be understood with three main strategies: (i) use of transition metals for luminescent centers171819202122, (ii) use of defects such as oxygen vacancies23242526 and (iii) use of materials such as tungstates and vanadates27282930.…”

mentioning

confidence: 99%

Rare-earth free self-luminescent Ca2KZn2(VO4)3 phosphors for intense white light-emitting diodes

Bharat

Jeon²,

Krishna

et al. 2017

Sci Rep

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The commercially available white-light-emitting diodes (WLEDs) are made with a combination of blue LEDs and yellow phosphors. These types of WLEDs lack certain properties which make them meagerly applicable for general illumination and flat panel displays. The solution for such problem is to use near-ultraviolet (NUV) chips as an excitation source because of their high excitation efficiency and good spectral distribution. Therefore, there is an active search for new phosphor materials which can be effectively excited within the NUV wavelength range (350–420 nm). In this work, novel rare-earth free self-luminescent Ca2KZn2(VO4)3 phosphors were synthesized by a citrate assisted sol-gel method at low calcination temperatures. Optical properties, internal quantum efficiency and thermal stability as well as morphology and crystal structure of Ca2KZn2(VO4)3 phosphors for their application to NUV-based WLEDs were studied. The crystal structure and phase formation were confirmed with XRD patterns and Rietveld refinement. The optical properties of these phosphor materials which can change the NUV excitation into visible yellow-green emissions were studied. The synthesized phosphors were then coated onto the surface of a NUV chip along with a blue phosphor (LiCaPO4:Eu2+) to get brighter WLEDs with a color rendering index of 94.8 and a correlated color temperature of 8549 K.

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mentioning

confidence: 99%

Rare-earth free self-luminescent Ca2KZn2(VO4)3 phosphors for intense white light-emitting diodes

Bharat

Jeon²,

Krishna

et al. 2017

Sci Rep

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“…Generally, these properties could be improved by better crystallization and purifying materials. Current challenges on phosphors research to obtain desired phosphors for lighting application is briefly reviewed in Table 1 respectively on luminescent features and high quantum efficiency [2][3][4][5][6][7], reduced of RE usage for host phosphor [8][9][10][11][12][13][14][15][16][17], morphology and size [18][19][20][21][22][23][24][25][26][27][28][29][30], preparation/synthesis methods [9,[31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48], and new phosphors …”

Section: Phosphor For Lighting Applicationsmentioning

confidence: 99%

“…Since several raw material of phosphors are highly demanding material, in turn the price increases. Therefore effort on replacing rare earth materials as host phosphors currently intense research was conducted to gain a non RE-based host phosphor [8][9][10][11][12][13][14][15][16][17]. However, some of them still use RE as doping element.…”

Section: Phosphor For Lighting Applicationsmentioning

confidence: 99%

Challenging and development of phosphors for lighting applications

Panatarani¹,

Joni²

2016

AIP Conference Proceedings

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Abstract. Phosphors (inorganics luminescent material) have been extensively investigated due to their potential application especially for lighting. This article briefly reviews the developments of the phosphors for lighting application. Research and development of phosphors for the application of energy-saving lamps have been developed in the Laboratory of Instrumentation System and Functional Materials Processing, Department of Physics, Universitas Padjadjaran. To fulfill the desired feature for lighting application, we developed host-center type phosphor with compositional modifications prepared by spray pyrolysis and simple solution routes. In order to meet the industry requirement with high production rate, currently we scaled up the spray pyrolysis utilized with a pulse combustion reactor.

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“…The strong afterglow reported previously for both undoped [18] and doped AlN phosphors [17] is consistent with the UV absorption populating the conduction band of AlN, and the subsequent delayed luminescence resulting from the presence of shallow traps (likely nitrogen vacancies). Other recent studies have found that AlN:Mn is an excellent cathodoluminescent phosphor [9], and reported emission efficiency of ~80% with 320 nm excitation [21]. There are no prior published studies of the use of AlN phosphors in a mercury discharge lamp, which is the focus of this paper.…”

Section: Introductionmentioning

confidence: 95%

Red-emitting manganese-doped aluminum nitride phosphor

et al. 2016

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We report high efficiency luminescence with a manganese-doped aluminum nitride redemitting phosphor under 254 nm excitation, as well as its excellent lumen maintenance in fluorescent lamp conditions, making it a candidate replacement for the widely deployed europium-doped yttria red phosphor. Solid-state reaction of aluminum nitride powders with manganese metal at 1900 °C, 10 atm N 2 in a reducing environment results in nitrogen deficiency, as revealed diffuse reflectance spectra. When these powders are subsequently annealed in flowing nitrogen at 1650 °C, higher nitrogen content is recovered, resulting in white powders. Silicon was added to samples as an oxygen getter to improve emission efficiency. NEXAFS spectra and DFT calculations indicate that the Mn dopant is divalent. From DFT calculations, the UV absorption band is proposed to be due to an aluminum vacancy coupled with oxygen impurity dopants, and Mn 2+ is assumed to be closely associated with this site. In contrast with some previous reports, we find that the highest quantum efficiency with 254 nm excitation (Q.E. = 0.86±0.14) is obtained in aluminum nitride with a low manganese doping level of 0.06 mol%. The principal Mn 2+ decay of 1.25 ms is assigned to non-interacting Mn sites, while additional components in the microsecond range appear with higher Mn doping, consistent with Mn clustering and resultant exchange coupling. Slower components are present in samples with low Mn doping, as well as strong afterglow, assigned to trapping on shallow traps followed by detrapping and subsequent trapping on Mn.

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A high efficiency rare earth-free orange emitting phosphor

Cited by 28 publications

References 47 publications

Rare-earth free self-luminescent Ca2KZn2(VO4)3 phosphors for intense white light-emitting diodes

Rare-earth free self-luminescent Ca2KZn2(VO4)3 phosphors for intense white light-emitting diodes

Challenging and development of phosphors for lighting applications

Red-emitting manganese-doped aluminum nitride phosphor

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