Color rendering and luminous efficacy of trichromatic and tetrachromatic LED-based white LEDs

Crystal structure, energy transfer mechanism and tunable luminescence in Ce3+/Dy3+ co-activated Ca20Mg3Al26Si3O68 nanophosphors

“…The Commission International de L'Eclairage (CIE) chromaticity coordinates,1931 [55] for CMAS: 1 m% Ce 3 þ , xDy 3 þ (x¼ 0.3, 0.5 and 1 mol%) under 348 nm excitation were evaluated depending on the emission spectra and represented in Fig. 16.…”

White-light-emitting KCl:Eu2+/KCN crystal for solid-state lighting devices

“…[4][5][6] Many materials have been used to obtain broad emission bands that cover a wide spectral range. However, this type of device oen exhibits a low Coloring Rendering Index (CRI) and low luminous efficiency mainly because of the difficulties in obtaining red-emission phosphors.…”

Thermal analysis of COB array soldered on heat sink

“…It is widely used for back light, signal light and general light because of its long lifetime, energy saving and environmental protection advantages [1][2][3]. However, as to the high power LED, only 20 to 30% of input power is transferred to light while the rest are all converted to heat.…”

“…One is to arrange surface mount type (SMT) high power LED packages on printed circuit board (PCB) [2,12] and the other is to arrange chips directly on PCB, which is called chip-on-board (COB) array [13]. Compared to the SMT high power LED array, COB array has many advantages on cost packaging densities and thermal management.…”