Among these phosphors
, [Sr.sub.2][Si.sub.5][N.sub.8]:[Eu.sup.2+] showed excellent emission characteristics under a blue excitation wavelength of 450 nm, had a uniform particle size distribution, and high performance in LED packages [16-18].
Most white LEDs use phosphors
excited by diode chips with short wavelengths (blue or violet) to reemit a broad spectrum light with a good color-rendering index [2-4].
Jones, "Electroluminescence in oxide phosphors
," Journal of Electrochemistry Society, vol.
Kyoceras high-color-rendering LED lighting, which combines violet LEDs with phosphors
and proprietary optical technologies, creates delicate illumination in a wide range of colors.
Because the current triphosphor blend discovered more than 30 years ago requires rare earth elements, researchers have identified new phosphors
that are more environmentally friendly.
David Peat, Product Specialist at Intertronics, worked with Plessey to recommend mixing and dispensing equipment for the LED phosphors
. The Thinky ARV-310 LED benchtop mixer is a non-contact planetary mixer which mixes, dispenses and degasses according to programmable mixing profiles.
were used for decades in VI, fluorescent lighting, they were deep-ultraviolet driven and not suited for use with blue LEDs, which emit light at a frequency of around 455nm.
Several researchers studied the luminescence properties of [Bi.sup.3+] doped phosphors
Sr[Al.sub.2][0.sub.4]: [Eu.sup.2+] phosphors
were used in this study, which put no radical threat or water harm and produce 3~5 higher luminescent intensity than common ZnS:Cu.
The formation of and mechanism for phosphorescence in strontium aluminate phosphors
have been thoroughly investigated, with Sr[Al.sub.2][O.sub.4]:[Eu.sup.2+], [Dy.sup.3+] phosphors
as one of the most studied hosts and a major host for long afterglow commercial products.
There are three ways to produce white LEDs: (i) combining a blue LED with a yellow phosphor
, for example, [Y.sub.3][Al.sub.5][O.sub.12]:[Ce.sup.3+], (ii) mixing red, green, and blue emissions from three LEDs, and (iii) exciting red/green/blue tricolor phosphors
with a near-UV LED (370-410 nm).
Figure 5 shows ML emission spectra of Mg[Al.sub.2][O.sub.4]: Dy (0.1 mol%) phosphors
. In order to find the luminescence centres responsible for ML emission, we have recorded ML spectrum.