2.4 Principle of White LED
17
much better color rendering of white light. up to more than 90. Furthermore, various
light colors can be combined by different proportions of phosphors, and have the
advantages of simple single chip control circuit. Unfortunately, the drawback of
such a design is that it is difficult and expensive to mix three phosphors, which also
restricts the popularity of this technology. The combination of blue and red LED with
cyan and green phosphors can achieve the best color rendering, but the technology is
limited due to its complexity, including control circuit and phosphor ratio, and other
issues needed to be further studied [19].
Single chip LED with phosphor to produce white light will inevitably cause energy
loss, that is, Stokes energy loss which is in the range of 10–30%. In order to further
improve the luminous efficiency of single-chip white LED and avoid the energy loss
caused by phosphor conversion, researchers have developed novel structure white
LED [20–22] through nano-pillar, nano-pyramid and quantum dot technology. These
approaches will be introduced in Chap. 12.
References
1. S. Pimputkar, J.S. Speck, S.P. DenBaars, S. Nakamura, Prospects for LED lighting. Nat.
Photonics 3, 179–181 (2009)
2. E.F. Schubert, J.K. Kim, Solid-state light sources get smart. Science 308, 1274–1278 (2005)
3. M.G. Craford, From Holonyak to today. Proc. IEEE 101, 2170–2175 (2013)
4. I. Akasaki, GaN-based p-n junction blue-light-emitting devices. Proc. IEEE 101, 2200–2210
(2013)
5. MorkoH. The p-n junction. Nitride Semiconductor Devices. Wiley. KGaA (2013)
6. Y.C. Shen, G.O. Mueller, S. Watanabe, et al. Auger recombination in InGaN measured by
photoluminescence. Appl. Phys. Lett. 91(14), 141101 (2007)
7. E.F. Schubert, T. Gessmann, J.K. Kim, Light emitting diodes. Wiley (2005)
8. H. Kroemer, The double-heterostructure concept: how it got starte. Proc. IEEE 101, 2183–2187
(2013)
9. S. Nakamura, N. Senoh, N. Iwasa, S.I. Nagahama, High-brightness INGAN blue, green and
yellow light-emitting-diodes with quantum-well structures. Jpn. J. Appl. Phys. Part 2 Lett.
1995, 34:L797-L799.
10. M.-H. Chang, D. Das, P.V. Varde, et al., Light emitting diodes reliability review. Microelectr
Reliabil. 52, 762–782 (2012)
11. M. Razeghi, Fundamentals of solid state engineering (Springer, US, 2006)
12. MorkoH. Optical Processes. Nitride Semiconductor Devices (Wiley, KGaA, 2013)
13. MorkoH. Light-emitting Diodes and Lighting. Nitride Semiconductor Devices (Wiley, KGaA,
2013)
14. H. Ries, I. Leike, J. Muschaweck, Optimized additive mixing of colored light-emitting diode
sources. Opt. Eng. 43, 1531–1536 (2004)
15. J. Orava, T. Jaaskelainen, J. Parkkinen, V.P. Leppanen, Diffractive CIE 1931 chromaticity
diagram. Color Res. Appl. 32, 409–413 (2007)
16. R. Mueller-Mach, G. Mueller, et al., Highly efficient all-nitride phosphor-converted white light
emitting diode. Phys. Status Solidi Appl. Mater. Sci. 202, 1727–1732 (2005)
17. D. Eisert, U. Strauss, S. Bader, et al., White light sources based on InGaN, in Proceedings of
the IWN 2000, Sep 24–27, 2000, Nagoya, Japan (2000)
18. L. Chen, C.C. Lin, C.W. Yeh et al., Light converting inorganic phosphors for white lightemitting diodes. Materials 3, 2172–2195 (2010)
17
much better color rendering of white light. up to more than 90. Furthermore, various
light colors can be combined by different proportions of phosphors, and have the
advantages of simple single chip control circuit. Unfortunately, the drawback of
such a design is that it is difficult and expensive to mix three phosphors, which also
restricts the popularity of this technology. The combination of blue and red LED with
cyan and green phosphors can achieve the best color rendering, but the technology is
limited due to its complexity, including control circuit and phosphor ratio, and other
issues needed to be further studied [19].
Single chip LED with phosphor to produce white light will inevitably cause energy
loss, that is, Stokes energy loss which is in the range of 10–30%. In order to further
improve the luminous efficiency of single-chip white LED and avoid the energy loss
caused by phosphor conversion, researchers have developed novel structure white
LED [20–22] through nano-pillar, nano-pyramid and quantum dot technology. These
approaches will be introduced in Chap. 12.
References
1. S. Pimputkar, J.S. Speck, S.P. DenBaars, S. Nakamura, Prospects for LED lighting. Nat.
Photonics 3, 179–181 (2009)
2. E.F. Schubert, J.K. Kim, Solid-state light sources get smart. Science 308, 1274–1278 (2005)
3. M.G. Craford, From Holonyak to today. Proc. IEEE 101, 2170–2175 (2013)
4. I. Akasaki, GaN-based p-n junction blue-light-emitting devices. Proc. IEEE 101, 2200–2210
(2013)
5. MorkoH. The p-n junction. Nitride Semiconductor Devices. Wiley. KGaA (2013)
6. Y.C. Shen, G.O. Mueller, S. Watanabe, et al. Auger recombination in InGaN measured by
photoluminescence. Appl. Phys. Lett. 91(14), 141101 (2007)
7. E.F. Schubert, T. Gessmann, J.K. Kim, Light emitting diodes. Wiley (2005)
8. H. Kroemer, The double-heterostructure concept: how it got starte. Proc. IEEE 101, 2183–2187
(2013)
9. S. Nakamura, N. Senoh, N. Iwasa, S.I. Nagahama, High-brightness INGAN blue, green and
yellow light-emitting-diodes with quantum-well structures. Jpn. J. Appl. Phys. Part 2 Lett.
1995, 34:L797-L799.
10. M.-H. Chang, D. Das, P.V. Varde, et al., Light emitting diodes reliability review. Microelectr
Reliabil. 52, 762–782 (2012)
11. M. Razeghi, Fundamentals of solid state engineering (Springer, US, 2006)
12. MorkoH. Optical Processes. Nitride Semiconductor Devices (Wiley, KGaA, 2013)
13. MorkoH. Light-emitting Diodes and Lighting. Nitride Semiconductor Devices (Wiley, KGaA,
2013)
14. H. Ries, I. Leike, J. Muschaweck, Optimized additive mixing of colored light-emitting diode
sources. Opt. Eng. 43, 1531–1536 (2004)
15. J. Orava, T. Jaaskelainen, J. Parkkinen, V.P. Leppanen, Diffractive CIE 1931 chromaticity
diagram. Color Res. Appl. 32, 409–413 (2007)
16. R. Mueller-Mach, G. Mueller, et al., Highly efficient all-nitride phosphor-converted white light
emitting diode. Phys. Status Solidi Appl. Mater. Sci. 202, 1727–1732 (2005)
17. D. Eisert, U. Strauss, S. Bader, et al., White light sources based on InGaN, in Proceedings of
the IWN 2000, Sep 24–27, 2000, Nagoya, Japan (2000)
18. L. Chen, C.C. Lin, C.W. Yeh et al., Light converting inorganic phosphors for white lightemitting diodes. Materials 3, 2172–2195 (2010)