Effect of Reassembled Remote Phosphor Geometry on the Luminous Efficiency and Spectra of White Light-Emitting Diodes With Excellent Color Rendering Property

Enhancement of efficiency and CCT uniformity for red phosphor thin films, red LEDs and laminated white LEDs based on near-ultraviolet LEDs using MgO nanoparticles

“…In region B, when MgO nanoparticles are doped, the direction of light propagation changes, and the absorption of NUV light and the forward transmission red emission light intensity increase signicantly, mainly because the scattering effect of MgO nanoparticles improves the absorption probability of NUV light by the phosphor (Rays ⑧, ⑪) and red light forward transmission (Ray ⑩). The increase in the probability of NUV light retroreection (Rays ⑥, ⑦) is due to the increase refractive index of PTFs, 33,40 as shown by the formula (2)-(5), enhancing the probability of total reection of NUV light at the air interface, as shown by the formula (6) and (7), so the overall performance is that the retroreective intensity of NUV light is enhanced, and forward transmission intensity is reduced.…”

“…3,4 Studies have shown that owing to differences of eld environment of phosphor matrix crystals, there is an overlap between the absorption and emission spectra of different phosphors, that is, the spectral re-absorption effect. [5][6][7] Therefore, the traditional hybrid coating structure easily causes the mutual absorption of energy and the internal energy consumption of photons of different wavelengths. In response to this phenomenon, researchers used stratication or partition of PTFs to attenuate the re-absorption and improve the device performances.…”

Micro-Prism Patterned Remote Phosphor Film for Enhanced Luminous Efficiency and Color Uniformity of Phosphor-Converted Light-Emitting Diodes

“…However, the SPE structure has a high correlated color temperature (CCT), which is not appropriate for lighting [13], and the CU is also unsatisfactory, caused by the concentrated blue radiation in the center. Various packaging designs, including diffused reflection Micromachines 2021, 12, 1117 2 of 10 cup [14], domed remote phosphor (RP) structure [15], and reassembled RP geometry [16] were proposed to enhance the LE of rpc-LEDs. However, those packaging structures suffer from compromised CU, thereby limiting their practical applications in lighting.…”

Effect of particle sizes and mass ratios of a phosphor on light color performance of a green phosphor thin film and a laminated white light-emitting diode

“…Due to the different phosphor matrixes, there are spectral overlap effects between different phosphors. 12–14 A direct hybrid coating will cause re-absorption of the emission spectrum, resulting in the internal consumption of excitation energy. Near-ultraviolet (NUV) LEDs that stimulate blue-green-red tri-primary phosphors are another way to achieve high-quality white light, 15,16 and there are more types of phosphors involved.…”