Heinrich Welker

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Heinrich Johann Welker (born September 9, 1912 in Ingolstadt ; † December 25, 1981 in Erlangen ) was a German physicist, particularly in the field of semiconductor technology .

One of his essential discoveries were III-V compounds (from elements of the 3rd and 5th main groups of the periodic table) and the prediction of their semiconductor properties. With his team at Siemens , he examined all possible constellations, including gallium arsenide (GaAs) - to this day an important component of high-frequency components or semiconductor lasers for optoelectronics - and thus paved the way for microwave semiconductor components as well as LEDs and laser diodes .

In addition, Welker devoted himself intensively to the problems of power electronics , arc technology and the optimal use of energy. As early as 1951, he developed the cracked gasifier , a device for gasifying liquid and liquid-like fuels (e.g. coal dust) into rich gases or cracked gases with exhaust gas recirculation, which enabled a mobile drive independent of oil or gas. However, the patent on it was not put to practical use.

In memory of his work, Siemens AG donated the Heinrich Welker Medal after his death , which is combined with the GaAs Symposium Award .

Live and act

Origin and education

Heinrich Welker was the older of the two sons of the Bavarian sergeant major Karl Welker, who came from the Herzogenaurach cloth making tradition, and his wife Berta, née Hecht. Both boys attended the humanistic grammar school in Ingolstadt . His brother Karl switched to studying at the Philosophical-Theological University of Eichstätt and, following examples from his relatives, became a Catholic priest who was particularly popular with the youth and who courageously took positions against those in power , but sometimes also for his "company" was rather uncomfortable employee.

Heinrich loved to play the violin and was more interested in things that can be proven experimentally. So he studied mathematics and physics in Munich from 1931 to 1935. He then became a scientific assistant to Arnold Sommerfeld at the Institute for Theoretical Physics at the University of Munich . In 1936 he received his doctorate with a thesis on wave mechanics . He then carried out investigations with superconductors and completed his habilitation in 1939 on a theoretical model of superconductivity at the University of Munich. Despite this excellent early phase of his academic career, he left the university out of political convictions.

Further career and life path

After his time at the University of Munich, he worked at the wireless telegraphic and air-electrical test station in Graefelfing (DVG). There he dealt with problems of ultra-short wave technology . In 1941 the DVG became part of the FFO (Aeronautical Radio Research Institute Oberpfaffenhofen) founded in 1937 .

In nearby Starnberg he married Elfriede on July 17, 1941; the marriage had three children.

From 1942 to 1945 he worked with Klaus Clusius at the Physico-Chemical Institute of the University of Munich. There he succeeded in proving the semiconductor properties of germanium , the "prototype of the semiconductor". He developed a rectifier arrangement for high frequency electromagnetic waves; the patent from it was used by Siemens until the end of the war to manufacture around 10,000 guide ladders from pure Germanium. In 1945 he wrote theoretical work on the capacitive ( capacitor ) control of electron currents via an insulator layer in a three-electrode semiconductor arrangement and developed the first theoretical description of the field effect transistor .

After Welker continued to work with semiconductor technology in his own engineering office in Planegg near Munich in 1946, he accepted an offer from Westinghouse's French subsidiary as laboratory manager in Paris. From 1947 to 1951, together with Herbert F. Mataré, he developed germanium diodes and at the same time and independently of the US researchers, the first European transistor , which was presented on May 18, 1949 and was called "Transistron". With this experience abroad he returned to Germany in 1951 and took over the management of the solid-state physics department at Siemens-Schuckertwerke in Erlangen in the “General Laboratory” (from 1953 “Research Laboratory”) . Here he succeeded in the synthetic production of III-V compounds, which led to the widespread use of galvanomagnetic and optoelectronic effects as well as new microelectronic circuits . Under his leadership, these new semiconductor substances were analyzed for stoichiometry and chemical stability as well as for their physical properties (structure, melting temperature, band gap and mobility). At that time he also discovered the barrier layers in germanium and their interpretation. In 1954 he was appointed honorary professor at the University of Munich.

In 1961, Welker took over the management of the entire research laboratory at Siemens-Schuckertwerke in Erlangen and, together with the research group he had set up, paved the way for microwave components as well as luminescence and laser diodes based on compound semiconductors. From 1963 he acted as a general representative of Siemens-Schuckertwerke. After Siemens & Halske AG, Siemens-Schuckertwerke AG and Siemens-Reiniger-Werke AG merged to form Siemens AG in 1966, the research laboratories in Munich and Erlangen were also merged in 1969 and placed under Welker. From 1973 he headed Central Research and Development and from 1974 as General Director of Central Technology, Central Research and Development at Siemens AG.

Even after his retirement in 1977, Welker continued to work in positions and work in science - his death on Christmas Day 1981 tore the 69-year-old from his thoughts about the still open problem of superconductivity in A-15 phases.

Functions and honors

for nuclear physics in Heidelberg
for metal research in Stuttgart
for chemistry in Mainz
  • Member of the editorial board of the journal "Wissenschaft und Technik"
  • Significant initiation of the "Physikalische Blätter" as a unified mouthpiece for the German Physical Society (DPG)
  • 1962 Dr.-Ing. E. h. of the Technical University of Karlsruhe
  • 1970 VDE honor ring (Association of German Electrical Engineers)
  • 1971 Full member of the Bavarian Academy of Sciences
  • 1973 International Prize for New Materials, first awarded by the American Physical Society for his discovery of III-V compounds
  • 1976 For the first time, the International Symposium on Gallium Arsenide and Related Compounds awards the GaAs Symposium Award in honor of Heinrich Welker (thereafter annually) - appointment to the award committee for the following years
  • After retiring in 1977, he was appointed President of the German Physical Society from 1978–79 . Here he devoted himself above all to improving the cooperation between pure and applied physics and, according to his wealth of experience, actively initiated the discussion in the field of the entire energy problem. Its international recognition has helped the DPG to deepen its connections - especially with scientists in the USA. After discharge from the presidency, he again turned to scientific questions and took up the open problem of superconductivity in A-15 phases.
  • 1978 Heinrich Hertz Prize , awarded by the University of Karlsruhe and the Badenwerk Foundation
  • 1978 Aachen and Munich Prize for Technology and Applied Natural Sciences
  • 1979 Honorary Doctorate from the University of Geneva
  • 1982 After the death of Heinrich Welker, Siemens AG donated the Heinrich Welker Medal , a gold medal that is combined with the GaAs Symposium Award and which was subsequently also awarded to its previous winners ( Welker Award ).
  • Posthumously, a street on the Siemens research site was named “Welkerweg” after him, giving him a place of honor in their “Walhalla” among greats such as Albert Einstein , Michael Faraday , Enrico Fermi and Werner Heisenberg .
  • On the 1st anniversary of his death, the Bavarian Academy of Sciences , the Ludwig Maximilians University in Munich, the German Physical Society and Siemens AG held a memorial colloquium in his honor, at which Otfried Madelung from the University of Marburg talked about “The III-V -Compounds and their meaning for semiconductor physics ”.

Via III-V connections

As early as the 1940s Heinrich Welker had developed ideas that when elements from the III. and V. Group of the Periodic Table of the Elements, new materials would have to be created whose properties are similar to the elements of Group IV - to which silicon and germanium belong - but which are even better suited for semiconductor purposes than the IV elements mentioned. Through the combination of indium and antimonide , he was able to show in 1951 that the electron mobility here is ten times greater than in germanium. Since it is primarily this electron mobility that matters in the technical application of semiconductors, Welker had achieved the decisive breakthrough. In the following period, all 16 possible compounds were produced in Siemens laboratories and their properties were examined. Although only a few turned out to be technically interesting, these few (e.g. gallium arsenide GaAs) became even more important in the course of the following decades. It is true that the abundant silicon, which began its triumphant advance in the late 1950s, is still the most important material today. But there are also things in the semiconductor sector that silicon cannot. Properties that are physically as interesting as the Gunn effect have only been demonstrated in the special band structure of III-V semiconductors. That is why the III-V connections have become irreplaceable. They are needed for light-emitting diodes and displays, for magnetically controllable semiconductor components, for photo and solar cells for optical communication (diode laser) and, last but not least, in high frequency technology.

Selected publications and patents

  1. H. Welker: General coordinates and condition equations in wave mechanics. In: Math. Annals. 113, 1936, pp. 304-319, online .
  2. H. Welker: About an electron-theoretical model of the superconductor. In: Z. f. techn. Phys. 19, 1938, pp. 606-611.
  3. H. Welker: On the electron theory of superconductivity. In: Phys. Z. 44, 1943, pp. 134-138.
  4. H. Welker: Superconductivity and magnetic exchange interaction. In: Z. f. Phys. 114, 1939, pp. 525-551.
  5. H. Welker: About the peak detector and its application to detect centimeter waves. In: Yearbook 1941 of German aeronautical research. Pp. III / 63-68.
  6. Patent DE966387 : Electric rectifier arrangement with germanium as semiconductor and method for producing germanium for such a rectifier arrangement. Inventor: K. Clusius, E. Holz, H. Welker (with priority dates October 2 and 3, 1942).
  7. Patent DE980084 : Semiconductor arrangement for capacitive control of currents in a semiconductor crystal . Registered on April 6, 1945 , inventor: H. Welker.
  8. Patent DE970420 : Device for gasifying liquid or liquid-like fuels. Registered on March 10, 1951 , inventor: H. Welker.
  9. Patent DE844373 : Device for gasifying liquid or liquid-like fuels. Registered on September 20, 1951 , applicant: Heinrich Ostwald, inventor: k. A. (in conjunction with patent DE2147220 : gap carburetor for the operation of internal combustion engines. Remember on September 22, 1971 , inventor H. Welker, A. Michel, Ch cook.. ).
  10. H. Welker: About new semiconducting connections. In: Z. f. Nature research. 7a, 1952, pp. 744-749 and 8a, 1953, pp. 248-251.
  11. H. Welker: Semiconducting Intermetallic Compounds. In: Physica. 20, 1954, pp. 893-909.
  12. H. Welker: On the theory of galvanomagnetic effects with mixed conduction. In: Z. f. Nature research. 6a, 1951, pp. 184-191.
  13. E. Weißhaar, H. Welker: Magnetic barriers in germanium. In: Z. f. Nature research. 8a, 1953, pp. 681-686.
  14. H. Welker: Objectives and priorities of the work of the research laboratory of Siemens-Schuckertwerke. In: Siemens-Z. 39 (1965) pp. 421-429.
  15. H. Welker: Aspects of industrial research. In: Siemens-Z. 48, 1974, pp. 970-973.
  16. H. Welker: New dimensions in physics through communication and computer science. Opening address by the President of the DPG at the 42nd Physics Conference 1978 in Berlin. In: Phys. Bl. 34, 1978, pp. 558-565. doi : 10.1002 / phbl.19780341202

Sources and literature

  • Herbert Goetzeler: Heinrich Welker: Discoverer of the semiconducting III-V compounds. In: Ernst Feldtkeller, Herbert Goetzeler (Hrsg.): Science pioneers at Siemens. Munich 1994, pp. 176-181.
  • Walter Heywang: Obituary for Heinrich Welker. In: Phys. Bl. 38 (1982) No. 3. doi : 10.1002 / phbl.19820380311
  • Ottfried Madelung Schottky-Spenke-Welker: Memories of the "founding years" of semiconductor physics in Germany after the Second World War , Physikalische Blätter, Volume 55, 1999, Issue 6, pp. 54–58. doi : 10.1002 / phbl.19990550614
  • Siemens Pl 0283.066: Heinrich Welker Medal donated, in Phys. Bl. 39 (1983) No. 4.
  • Erlanger Nachrichten - City of Erlangen June 6th, 1975: Groundbreaking in the field of semiconductors
  • Erlanger Nachrichten - City of Erlangen February 13th (possibly 1982): Basis for semiconductor technology created
  • Siemens personnel file
  • Registration register of the city of Erlangen (archive information August 9, 2007)
  • Matthäus Welker (cousin, † 1987): Proof of Aryan descent (August 19, 1937) and explanations (11/1972),
verified by Bürgeramt Ingolstadt (2007)

Web links

Individual evidence

  1. Patent FR1010427 : Nouveau système cristallin à plusieurs électrodes réalisant des effects de relay électroniques. Registered on August 13, 1948 , applicant: Westinghouse, inventor: HF Mataré, H. Welker.
  2. Patent US2673948 : Crystal device for controlling electric currents by means of a solid semiconductor. Applicant: Westinghouse, inventor: HF Mataré, H. Welker (French priority of August 13, 1948).
  3. ^ Armand Van Dormael: The “French” Transistor. In: Proceedings of the 2004 IEEE Conference on the History of Electronics, Bletchley Park, June 2004. ( PDF ( Memento of June 20, 2007 in the Internet Archive )).