Flexible fabrication of a patterned red phosphor layer on a YAG:Ce³⁺ phosphor-in-glass for high-power WLEDs

Abstract

We proposed a flexible and mask-less approach to directly fabricate a patterned red phosphor layer on a Y 3 Al 5 O 12 :Ce 3+ (YAG:Ce 3+) phosphor-in-glass (PiG) for high-power white light-emitting diodes (WLEDs). This approach was realized by ultraviolet (UV) assisted and initiative cooling based water condensing. A low-temperature precursor glass matrix with a high refractive index was synthesized for the YAG:Ce 3+ PiG. By controlling the UV pre-curing time, the micro-concaves with adjustable sizes were fabricated on the red phosphor layer embedded with UV-curable polymer. With the pre-curing time of 20 s, 30 s, and 40 s, the average aspect ratio of the micro-concave is 1.03, 0.76, and 0.41, respectively. Consequently, the patterned sample achieves a highest luminous efficacy (LE) of 108.5 lm/W at the current of 350 mA, which is 16.2% higher than the unpatterned sample. The corresponding correlated color temperature (CCT) and color rendering index (CRI) are 4831 K and 80.5, respectively. The results demonstrate that the YAG:Ce 3+ PiG coated with the water condensing patterned red phosphor layer is a feasible and effective method to enhance the light extraction and color quality of high-power WLEDs.

Recycled Glass and Ce‐Doped‐Y3Al5O12 Nanoparticles Phosphor‐in‐Glass for White Light‐Emitting Diodes Applications

“…[ 11–16 ] Typically, PiG using TeO 2 ‐based glasses is fabricated by sintering (below 800 °C) a mixture of YAG:Ce and the designed inorganic low‐melting glass frits at an optimal temperature. [ 17–19 ]…”

Enhancing the CRI and lumen output for the 6600 K WLED with convex-dual-layer remote phosphor geometry by applying red-emitting MGSR3SI2O8:EU2+,MN2+ phosphor

“…Nevertheless, constructing a white LED package with tunable correlated color temperatures (CCTs), high efficiency, and superior CRI is a real challenging task to accomplish [11,12]. Previously, the structure of a blue chip combined with two phosphor materials was applied to reach a high value of CRI, but the efficacy is poor because of the Stokes shift [13][14][15][16]. Then, the implement of the two red and blue chips together with one phosphor resulted in an increase in CRI and efficacy but was unable to tune the color, in comparison with the structure consisting of two phosphors.…”

The application of green YPO4:Ce3+,Tb3+ and red LiLaO2:Eu3+ layers to remote phosphor LED

“…With such a wide distance of phosphor and the LED chip, the light loss from back-scattering event and inner reflection is reduced. This solution does not only solve the problem of poor thermal performance but also raise other optical properties of WLEDs such as light output and chromatic performance [11][12][13][14][15][16]. Nevertheless, advanced lighting demands cannot be fulfilled with the current state of remote structure lighting devices although these devices are still compatible for standard occasions.…”