Cyan Phosphor Research Articles

An excellent cyan-emitting orthosilicate phosphor for NUV-pumped white LED application

The Ba9Lu2Si6O24:Ce3+cyan phosphor has excellent luminescence properties and displays promising application in NUV-based white LEDs with high performance.

Enhance Color Rendering Index via Full Spectrum Employing the Important Key of Cyan Phosphor.

A new concept called "full-spectrum lighting" has attracted considerable attention in recent years. Traditional devices are usually combined with ultraviolet-light-emitting diode (LED), red, green, and blue phosphors. However, a cyan cavity exists in the 480-520 nm region. Hence, cyan phosphors are needed to compensate for the cavity. (Sr,Ba)5(PO4)3Cl:Eu2+ phosphors feature an extremely unique and tunable photoluminescence spectrum. Nevertheless, the tuning mechanisms of these phosphors remain unclear. In this study, we elucidate the mechanism of the cation size-controlled activator uneven-occupation and reoxidation in (Sr,Ba)5(PO4)3Cl:Eu2+ phosphors. This mechanism could help tune the optical properties of related apatite families and structures with multiple cation sites and strongly uneven occupation of activators and cations. Finally, the package of the LED device is constructed to show that both color rendering index Ra and R9 are higher than 95. Thus, the device could be a potential candidate for full-spectrum lighting.

Excellent color rendering indexes of multi-package white LEDs

This study introduces multi-package white light-emitting diodes (LEDs) system with the ability to realize high luminous efficacy and an excellent color rendering index (CRI, R a) using the R B,M A B,M G B,M C B (R B,M A B,M G B,M denoted as a long-pass dichroic filter (LPDF)-capped, monochromatic red, amber and green phosphor converted-LED (pc-LED) pumped by a blue LED chip, and C B denoted as a cyan and blue mixed pc-LED pumped by a blue LED) system. The luminous efficacy and color rendering index (CRI) of multi-package white LED systems are compared while changing the concentration of the cyan phosphor used in the paste of a cyan-blue LED package and the driving current of individual LEDs in multi-package white LEDs at correlated color temperatures (CCTs) ranging from 6,500 K (cold white) to 2,700 K (warm white) using a set of eight CCTs as specified by the American National Standards Institute (ANSI) standard number C78.377-2008. A R B,M A B,M G B,M C B white LED system provides high luminous efficacy (≥ 96 lm/W) and a color rendering index (≥ 91) encompassing the complete CCT range. We also compare the optical properties of the R B,M A B,M G B,M C B system with those of the R B,M A B,M G B,M B and RAGB (red, amber, green, and blue semiconductor-type narrow-spectrum-band LEDs) systems. It can be expected that the cyan color added to a blue LED in multi-package white LEDs based on LPDF-capped, phosphor-converted monochromatic LEDs will meet the needs of the high-quality, highly efficient, full-color white LED lighting market in the near future.

High luminescent Li_2CaSiO_4:Eu^2+ cyan phosphor film for wide color gamut field emission display

Li(2)CaSiO(4):Eu(2+) cyan phosphor screen for enlarging the color gamut of field emission display has been prepared and characterized. The luminance of Li(2)CaSiO(4):Eu(2+) phosphor film can reach as high as about 12000 cd/m(2) under the conditions of V(a) = 7 kV and J(a) = 2.8 mA/cm(2). The cathodoluminescent spectrum, luminance, saturation current density and degradation property are compared with another cyan phosphor Mg(2)SnO(4):Ti(4+),Mn(2+). It is found that Li(2)CaSiO(4):Eu(2+) phosphor exhibits narrower emission band, higher luminance, higher saturation current density, higher resistance to electron bombardment, higher thermal stability and conductivity as well as purer color. Thus, Li(2)CaSiO(4):Eu(2+) has great potential in application in field emission display as well as light emitting diode.

A Cyan-Emitting BaSi7N10 : Eu2 + Phosphor Prepared by Gas Reduction and Nitridation for UV-Pumping White LEDs

An -activated cyan phosphor for UV-pumping white light-emitting diodes (LEDs) was successfully synthesized by direct gas reduction and nitridation of the homogeneous oxide precursor of a system in flowing and mixture gas. The phase purity, morphology, chemical composition, and luminescence properties were investigated. The effect of activator concentration on the optical properties of in was discussed. The synthesized powders have a nearly pure phase and consist of microsized particles. -doped phosphors absorb strongly in the UV part of the electromagnetic spectrum and exhibit an intense cyan emission band centered at 482–500 nm, which agrees with earlier papers. The optical properties depend greatly on the concentration. Under an UV excitation, phosphors doped with a 20 atom % activator give the best luminescent properties, such as high emission intensity, high quantum efficiency, and very low thermal quenching, which suggests that -doped can be a good green-blue phosphor for UV-pumping white LEDs.

Voltage‐Controlled Multicolor CRT Phosphors: Preparation and Characteristics

Since the range of electrons in a solid is a function of their initial energy it is possible to construct high‐resolution multicolor cathode‐ray phosphor screens in which the color is determined by the accelerating potential. A nonluminescent layer of controlled thickness is formed upon the surface of each grain of a green or cyan phosphor. This coating is prepared either by the diffusion of a killer impurity such as cobalt from the surface into the bulk or by the homogeneous precipitation of undoped upon each phosphor grain. The coated phosphor is then intimately mixed with any efficient standard red emitting phosphor such as or . A screen consisting of an intimate mixture of two component phosphors is then deposited by the same method used to prepare monochrome screens. Four distinct colors, useful for information display, can be observed in the red‐green system. Quite acceptable two‐primary‐color television pictures have been demonstrated in the red‐ cyan phosphor system.