The location points with values are in terms of the CIE 1931 chromaticity diagram
, as shown in Figure 5.
Different volumes of cochineal dye (pH = 12, ) in 1 ml of AgN[O.sub.3] solution (10 mM, pH = 5.6) were analyzed with UV-Vis spectrometry, Commission Internationale de l'Eclairage (CIE) chromaticity diagram
, cyclic voltammetry (CV), scanning transmission electron microscopy (STEM), energy dispersive X-ray spectroscopy (EDS), dynamic light scattering (DLS), and X-ray diffraction (XRD).
By using the CiE chromaticity diagram
of emission spectra, it has been shown that this GdV[O.sub.4]:[Sm.sup.3+] nanophosphor material (chromaticity coordinates x = 0.596, y = 0.398) can be used for development of orange-reddish light emitting optical devices.
Figure 8(c) shows the CIE chromaticity diagram
for 3 mol% Sm doped NaY[F.sub.4] micro/nanoplates under 399 nm excitation wavelength.
Figure 6 shows CIE x, y chromaticity diagram
of EL device with ZnS:Cu phosphor change in thickness which responded to green-blue color.
The most accurate metric to describe the color shift of a light source is #u'v'--that is, the change in u'v' coordinates on the International Commission on Illumination (CIE) 1976 (u'v') chromaticity diagram
, which is the most visually uniform diagram of a light source's color.
The ranges of tolerable variations in color are plotted as ellipses on a CIE x/y chromaticity diagram
, and can be categorized into 1-step (the human eye is unable to perceive any variation in color among devices), 2-step to 3-step (levels where color variations are difficult to perceive), and 4-step to 7-step (levels where color variations are noticeable to the human eye.
Finally, the measured colour coordinates of the high-power LEDs are depicted in the CIE 1931 colour space chromaticity diagram
According to the definition, we calculate the normalized chromaticity coordinate x, y, z in the equation below, which can be pointed in the chromaticity diagram
CIELUV chromaticity diagram
has elongated the blue-red portion of the diagram and relocated white point to decrease the visual disparity with the green portion.
Colours can be matched to the CIE 1931 xyY Chromaticity Diagram