
126 Solid-State Light Sources
400
Relative Intensity
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
500 600
700 400
Relative Intensity
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
500 600
700
400
Relative Intensity
0.0
0.1
0.2
500 600
Wavelength/nm
700 400
Relative Intensity
0.0
0.2
0.4
0.6
0.8
1.0
1.2
(a) (b)
(c) (d)
500 600
Wavelength/nm
700
Figure 4.19. Various emission spectra of white LEDs. (a) Blue LED with phosphor while the
other three spectra (b), (c), and (d), belong to dichromatic, trichromatic, and tetrachromatic
quantum dot LEDs, respectively.