Raphael Tsu
Raphael Tsu | |
|---|---|
| Born | |
| Known for | resonant tunneling diode, Tsu-Esaki Formula |
| Awards | Alexander von Humboldt Award (1975) James C. McGroddy Prize for New Materials (1985) |
Raphael Tsu is a Fellow of the American Physical Society and currently serves as a Distinguished Professor of electrical engineering at the University of North Carolina at Charlotte, Charlotte, NC.
Biography
Tsu was born to a Catholic family in Shanghai, China. As a child he was inspired by his great uncle who in 1926 was amongst the first six Chinese bishops ever to be consecrated at the Vatican in Rome and as a teenager by his US educated father Adrian and French educated uncle, Louis. His paternal grandfather and great uncle were pioneers in power plant and modern shipyard in Shanghai. While leaving Shanghai, his great uncle, on his death bed told him to remember the old Chinese saying that to succeed requires the right tool. Tsu initially emigrated to the west to study physics in England. He earned a B.S. at the University of Dayton, and M.S. & Ph.D. from the Ohio State University. After several years working as a member of the Technical Staff at Bell Laboratories (BTL) at Murray Hill, NJ, developing an ultrasonic amplifier, a mechanism invented by Dr. D.L. White, Tsu moved to the IBM, T.J. Watson Research Center in Yorktown Heights, NY as an associate to Dr. Leo Esaki beginning a well-known collaboration that yielded a theory of man-made quantum materials, superlattices and quantum wells.
Later, Tsu joined the Amorphous Semiconductors Institute (ASI) and directed energy research at Energy Conversion Devices (ECD) near Detroit, MI, as invited by inventor Stan Ovshinsky. His contribution included the first experimental determination of the volume fraction of crystallinity for conductivity percolation in amorphous silicon and [germanium][1], and providing experimental proof of the existence of an intermediate order.[2] He discovered experimentally that post annealing with H2 and O2 can drastically remove dangling bond defects in amorphous silicon.
During 1985-1987 Tsu served as the amorphous silicon program group leader at the National Renewable Energy Laboratory (then known as SERI, Solar Energy Research Institute) in Golden, CO. His theoretical derivation of the relationship between the optical absorption and disorder in amorphous silicon and germanium in terms of fundamental constants shows that the slope of the Tauc plot is uniquely determined by the oscillator strength of the transition, the deformation potential and the mean deviation of the atomic coordinates obtained from the RDF.
In 1972, Tsu organized a group and was invited by the Chinese Science Academy which resulted in the first report on the technology in China published in Scientific American. This led to his involvement through establishing the first Chinese Scientific delegation visit to the US, which was invited by the US-China Relations Committee of the US Academy of Science. During this visit, he worked with the US State Department for the program and logistics on the East Coast. This effort contributed to the opening of scientific exchange between the United States and China.
Notable Papers
- R. Tsu and L. Esaki (1973). "Tunneling in a finite superlattice". Applied Physics Letters. 22: 562. doi:10.1063/1.1654509.
References
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R. Tsu, J. G. Hernandez, S. S. Chao, S. C. Lee and K. Tanaka (1982). "Critical Volume Fraction of Crystallinity for Conductivity Percolation in P-doped Si:F:H Alloys". Applied Physics Letters. 40: 534. doi:10.1063/1.93133.
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R. Tsu, M. Isu, S. R. Ovshinsky and F. H. Pollak (1980). "Electroreflectance and Raman Investigation of Glow-Discharge Amorphous Si:F:H". Solid State Communications. 36: 817. doi:10.1016/0038-1098(80)90019-8.
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