MRS Bulletin

Technical Feature

Technical Feature

Current Status of GaN-Based Solid-State Lighting

Shuji Nakamura

Abstract

The continuous improvement in luminous efficacy of “white” light-emitting-diode (LED) sources offers the potential of considerable energy savings in general lighting applications. Recent experiments at UCSB have demonstrated 117 lumens per watt (lm/W) in white LEDs, with further improvements expected in the near future. Considerable progress has also been achieved using nonpolar GaN, such as a-plane {1120} and m-plane {1100} GaN, or semipolar GaN substrates. Such devices avoid the deleterious effects of charge separation due to spontaneous and piezoelectric polarization inherent in most c-axis-oriented devices.

Shuji Nakamura is a professor in the Materials Department at the University of California, Santa Barbara (UCSB). He received his BE (1977), MS (1979), and PhD (1994) degrees in electrical engineering from the University of Tokushima, Tokushima, Japan. Nakamura joined Nichia Chemical Industries in 1979 and moved to his present position at UCSB in 2000. His major achievements have been in the development of Group III nitridebased light-emitting diodes and laser diodes. Nakamura was elected as a member of the U.S. National Academy of Engineering in 2003. He holds more than 100 patents and has published more than 200 papers in this field. In addition, Nakamura has been awarded the Nishina Memorial Award (1996), the Materials Research Society (MRS) Medal (1997), the Institute of Electrical and Electronics Engineers (IEEE) Jack A. Morton Award, the British Rank Prize (1998), the Benjamin Franklin Medal Award (2002), and the Millennium Technology Prize (2006).

Nakamura can be reached by e-mail at shuji@engineering.ucsb.edu.

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