Professor Kroemer received a Ph.D. in Theoretical Physics in 1952 from the University of Göttingen, Germany, with a dissertation on hot-electron effects in the then-new transistor, setting the stage for a career in research on the physics of semiconductors and semiconductor devices. Following work in a number of research laboratories in Germany and the USA, Kroemer persuaded the ECE Department at UCSB in 1976 to put all resources it had available for expanding their small semiconductor research program, not into mainstream silicon technology, but into the emerging compound semiconductor technology. In this field, Kroemer saw an opportunity for UCSB to become one of the leading institutions. He himself became the first member of the group, thus founding what has indeed grown into a large group that is second to none in the physics and technology of compound semiconductors and devices based on them.

In his research. Prof. Kroemer has always preferred to work on problems that are one or two generation ahead of established mainstream technology. In the mid-'50-s, he was the first to point out that great performance advantages could be gained in various semiconductor devices (initially bipolar transistors) by incorporating what is now called heterojunctions into the devices. Most notably, in 1963 he proposed the concept of the double-heterostructure laser, the central concept in the field of semiconductor lasers, without which that field would simply not exist [1, 2] . These ideas were far ahead of their time, and required the development of modern epitaxial growth technology before they could become mainstream technologies, in turn providing a great stimulus towards the development of these technologies. But by 1980 the technology had progressed to the point that the 80's became a decade of "Heterostructures for Everything"— a topic that continues to dominate compound semiconductors, and is even invading mainstream Silicon technology.

After coming to UCSB, Kroemer turned to experimental work and became one of the early pioneers in molecular beam epitaxy, concentrating from the outset on applying the technology to untried new materials systems, such as GaP and GaAs on Silicon. Since 1985, his work has shifted towards the "6.1Å group" of materials, InAs, GaSb, and AlSb, a group where he saw great opportunities for future devices. All his current research involves this materials combination, in a number of projects that involve high-performance devices , materials research, and new areas of solid-state physics.

His dominant current interest is in superconductor-semiconductor heterostructures involving InAs-AlSb quantum wells contacted by superconducting niobium electrodes. In such structures, the superconducting electrodes in essence induce superconductivity in the semiconductor. Of all semiconductors, InAs is the best material for the construction of such devices. With its existing leadership in InAs quantum well technology, Prof. Kroemer's group was in an unique position to exploit these possibilities. Through a number of new discoveries, the group has become the leading research group in this emerging new field of super-semi structures. Although this is basically still a solid-state physics project, the study of potential applications to future devices forms an integral part of the research [3-5] . Although Prof. Kroemer can no longer commit himself to beginning graduate students for research in this field, he still welcomes postdoc applicants with an appropriate background that would permit immediate participation in the research.

Prof. Kroemer's research has been widely recognized by the semiconductor community, and he has been honored with numerous awards, including several national and international ones:

• J.J. Ebers Award of the Electron Devices Group of the IEEE (1973)

• Heinrich Welker Medal of the International Symposium on GaAs and Related compounds (1982)

• National Lecturer, IEEE Electron Devices Society (1983)

• UCSB Faculty Research Lecturer (1985)

• Honorary Doctorate in Engineering, Technical University of Aachen, Germany (1985)

• Jack Morton Award of IEEE (1986)

• Donald W. Whittier Chair in Electrical Engineering (1986)

• Alexander von Humboldt Research Award (1994)

• National Academy of Engineering (1997)

Selected Publications:

[1] H. Kroemer, "A Proposed Class of Heterojunction Lasers," Proc. IEEE, vol. 51, pp. 1782-1783, 1963.

[2] H. Kroemer, "Solid State Radiation Emitters," U.S. Patent 3,309,553, March 14, 1967. (Filed Aug. 16, 1963).

[3] H. Kroemer, C. Nguyen, and E. L. Hu, "Electronic Interactions at Superconductor-Semiconductor Interfaces," Solid-State Electron., vol. 37, pp. 1021-1025, 1994. (Proc. MSS-6, Garmisch-Partenkirchen, Germany, Aug. 1993, invited).

[4] H. Kroemer, C. Nguyen, E. L. Hu, E. L. Yuh, M. Thomas, and K. C. Wong, "Quasiparticle transport and induced superconductivity in InAs-AlSb quantum wells with Nb electrodes," Physica B, vol. 203, pp. 298-306, 1994. (Proc. NATO Advanced Research Workshop on Mesoscopic Superconductivity, Karlsruhe, 1994).

[5] H. Kroemer, C. Nguyen, and E. L. Hu, "Ballistic Electron Transport and Superconductivity in Mesoscopic Nb-(InAs/AlSb) Quantum Well Heterostructures," 21st Internat. Symposium on Compound Semiconductors, San Diego, 1994, H. Goronkin, Ed., Inst. Phys. Conf. Ser., vol. 141, Institute of Physics, pp. 7-12.

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