TABLE 3.3 Comparison of Lighting Sources by Various Metrics

Incandescent Fluoicscent LEDs OLEDs
Efficacy (lab demo) 231 InvW-white 100lm/W
150 lm/W - warni white
Efficacy(commcrcial) 17 lm/W lOOlnVW lOO-1201m/W-whitc 50 lm/W panel
CMI 100 8O-85 85 - white Up to 95
95-warm white
Form factor Hcjt gencrating Lorn; or compact gas tilled glass tube Point source high-intensity lamp Large area thin diffuse source Flexible, transparent
Safely concerns Very hot Contains nercury Very hot operation None to date
Lifetime (hours) 1,000 20.000 50.000 30.000
Dimmablc? Yes, but much lower efficacy Yes, efficiency decreases Yes, efficiency increases Yes. efficiency increases
Noise No Yes No No
Cost ($/klm) 0.50 1.0 7.0 100-250

OLEDs can be designed and fabricated with exceptionally high internal efficiencies, rendering virtually any desired color, but there has not yet been a sufficient manufacturing infrastructure established to understand the practical issues and costs of scaling up this device technology into a practical and ubiquitous lighting source. Considerable additional efforts are needed to optimize light extraction, extend device lifetimes, reduce the roll off in efficiency at high brightness, and improve operational lifetime. The inorganic LEDs form “point-sources” of light while OLEDs lend themselves to unusual, conformable, and flexible form factors, offering diffuse lighting over large areas. Thus, the two technologies provide complementary lighting solutions, depending on particular lighting applications and venues. Investments in fundamental advances in OLED materials and device architectures, at this stage, may be the deciding factors in their ultimate success and the widespread adoption of this very promising lighting technology. On the other hand, the inorganic LEDs have already made the transition to widespread manufacturing and commercialization, yet still face substantial challenges to longer-term success. Issues of higher efficiency and more robust and reliable operation at lower cost similarly require continued investments into the technology, both at the fundamental level of materials and device improvement, as well as at the level of manufacturing and systems-level improvements.

REFERENCES

Akasaki, I., H. Amano, K. Itoh, N. Koide, and K. Manabe. 1992. “GaN Based UV/blue Light-Emitting Devices.” Presentation to the Institute of Physics Conference Series: GaAs and Related Compounds. London: Institute of Physics Publishing.

Amano, H., N. Sawaki, I. Akasaki, and Y. Toyoda. 1986. Metalorganic vapor-phase epitaxial-growth of a high quality GaN Film. Applied Physics Letters 48(5):353-355.

Avrutin, V., D.J. Silversmith, Y. Mori, F. Kawamura, Y. Kitaoka, and H. Morkoc. 2010. Growth of bulk GaN and AlN: Progress and challenges. Proceedings of the IEEE 98(7).

Baldo, M.A., D.F. O’Brien, Y. You, A. Shoustikov, M.E. Thompson, and S.R. Forrest. 1998. High efficiency phosphorescent emission from organic electroluminescent devices. Nature 395:151.

Baldo, M.A., S. Lemansky, P.E. Burrows, M.E. Thompson, and S.R. Forrest. 1999a. Very high efficiency green organic light emitting devices based on electrophosphorescence. Applied Physics Letters 76:4.

Baldo, M.A., D.F. O’Brien, M.E. Thompson, and S.R. Forrest. 1999b. The excitonic singlet-triplet ratio in a semiconducting organic thin film. Physical Review B 60:14422.

Blochwitz, J., M. Pfeiffer, T. Fritz, and K. Leo. 1998. Low voltage organic light emitting diodes featuring doped phthalocyanine as hole transport material. Applied Physics Letters 73:729.

Brus, L. 1991. Quantum crystallites and nonlinear optics. Applied Physics A 53:465-474.

Burrows, P.E., V. Bulovic, S.R. Forrest, L.S. Sapochak, D.M. McCarty, and M.E. Thompson. 1994. Reliability and degradation of organic light emitting devices. Applied Physics Letters 65:2922.

Bush, S. 2008. Lumileds talks LED packaging—Interview. Electronics Weekly.com, March 26.

Cree, I. 2012. Cree Sets New R&D Performance Record with 254 Lumen-Per-Watt Power LED. Available at http://www.cree.com/news-andevents/cree-news/press-releases/2012/april/120412-254-lumen-perwatt. Accessed July 1, 2012.

D’Andrade, B.W., J. Esler, C. Lin, V. Adamovich, S. Xia, M.S. Weaver, R. Kwong, and J.J. Brown. 2008. Realizing white phosphorescent 100 lm/W OLED efficacy. Proceedings of SPIE 7051:70510Q.



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement