Fyzikální ústav Akademie věd ČR

Jan Tauc deceased at the age of 88 on 28th December 2010 in Washougal, Wa, in the West of US. The Czech science loses in his person one of its most significant physicists of the post war era, the founding personality of solid state physics and a scientist of world renown, who spent a major part of his professional life in the Institute of Solid State Physics of the Czechoslovak Academy of Sciences in Cukrovarnická Street, Prague – Střešovice.

Prof. Ing. Dr. RNDr. Jan Tauc, DrSc, was born in Pardubice on 15th April 1922. He finished the high school during the War. After the war he graduated from the Czech Technical University in Prague (1949) and from the Faculty of Science of the Charles University in Prague (1956). Since 1949 he worked at the Military-Technical Institute in Tanvald. There he realized the importance of the then nascent field of semiconductors, to which he consecrated his whole professional career. His first achievement was the creation of the first germanium transistor in Czechoslovakia. To this goal he joined forces with Zdeněk Trousil. Together, both joined in 1952 the emerging Institute of Technical Physics of the Czechoslovak Academy of Sciences in Cukrovarnická Street (later Institute of Solid State Physics, now the Division of Condensed Matter Physics, AS CR), where Jan Tauc constitutes and until 1969 heads the Department of Semiconductors. This laboratory conceived in modern spirit as joining fundamental physical investigations with the emerging materials research, becomes within a few years one of the world centres of semiconductor physics. JT himself first devotes his activity to the problem of electromotive forces in semiconductors. He discovers bulk photovoltaic effect, anomalous thermal effect, photomagnetic effect and photopiezoelectric effect. He summarizes the whole newborn field in a book published by Pergamon Press, later translated to many languages. For these studies he was awarded his first State Prize (as a non-party man in 1955!). He was commissioned by IUPAP to organize the Vth International Conference on the Physics of Semiconductors in Prague, 1960. This conference was exceptional as the first large international meeting on physics that took place behind the Iron Curtain. There Jan Tauc presented his seminal contribution to another newly emerging field – study of the interband transitions by optical measurements. Together with Emil Antončík, he identified the fundamental absorption band in Ge and III-V semiconductors with the aid of spin-orbit splitting. On further development of this issue, JT was fascinated by the problem of the loss of translational symmetry in a solid. Luckily, he joined forces with Radu Grigorovici from Bucharest and authored fundamental papers on the optical absorption edge in amorphous tetrahedral semiconductors. In 1965, he invited to Prague some 30 scientists to participate at the First International Conference on Amorphous Semiconductors. This event was at the beginning of the explosive development of the field of amorphous semiconductors on the world-wide scale. The following fruitful years of intensive work were disrupted by sinister political development after 1968. Jan Tauc makes use of the last opportunity and leaves the country, heading for a stay at Bell Labs, US, in 1969.

Dr Jan Tauc in his lab in the Building C in Cukrovarnická Street (about 1957).

This opens up the second, longer part of the professional career of JT – in emigration in the US. Since 1970 he served for 22 years as a Professor of the Brown University in Providence, R.I., remaining Professor Emeritus till his decease. In 1983-88 he headed there the Laboratory for Materials Research. He was also a long-term consultant of Bell Labs. Amorphous semiconductors, in particular hydrogenated silicon, remained the main field of his interest. He comes with a novel concept, photomodulation spectroscopy of semiconductors. To this end he makes use of the then novel technique of picosecond and, since the beginning of 1980s, femtosecond optical pulses. This research had an unexpected sequel - the discovery of generation of surface phonons by means of optical pulses (1989). This phenomenon became the basis of a new nondestructive method of probing of thin-film structures, the picosecond ultrasonics.

Deceased Jan Tauc leaves behind not only extensive original work, but also a deep trace of his organizational and pedagogical efforts (he was professor at Charles University, director of the Institute of Physics of Charles University and, later, professor at Brown University). Two points cannot remain unmentioned: JT introduced to our country the concept of summer schools and, together with E. Antončík, organized the first one – the legendary Podhradí (1963). JT was also the founding member of the European Physical Society (1968).

Jan Tauc also came in for numerous honors and recognitions: he was granted two Czechoslovak State Prizes, Hlávka’s Medal of the Czechoslovak Academy of Sciences, De Scientia et Humanitate Optime Meritis Medal of the Academy of Sciences of the Czech Republic, the Humboldt Foundation Fellowship, Frank Isakson Award and David Adler Award, both from the American Physical Society, and several others. He was a Corresponding member of the Czechoslovak Academy of Sciences, Honorary Fellow of The Learned Society of the Czech Republic, Member of the National Academy of Sciences (USA).

The family life of Jan Tauc was a happy one. He lost his loving wife Vera after 62 years of marriage (†2009). He is survived by his daughter and son, and four grandchildren.