Heinrich Welker
Encyclopedia
Heinrich Johann Welker was a German
theoretical and applied physicist
who invented the "transistron", a form of transistor
made at Westinghouse independently of the first successful transistor made at Bell Laboratories. He did fundamental work in III-V compound semiconductor
s, and paved the way for microwave
semiconductor
elements and laser diode
s.
, and was granted a Ph.D. in 1936. The book Electrodynamics - Lectures on Theoretical Physics Volume III by Sommerfeld was based on lecture notes prepared by Welker during the winter semester of 1933/1934. Welker was granted his Habilitation
under Sommerfeld in 1939.
During the war years
, 1940 to 1945, Welker worked at Luftfunkforschungs Institut in Oberpfaffenhofen
, but still maintained association (1942 to 1944) with the physicochemical institute of Klaus Clusius
at the University of Munich. After the war, 1947 – 1951, he took a job at the Westinghouse
subsidiary in Paris
, Compagnie des Freins et Signaux Westinghouse. From 1951 to 1961, Welker headed of the solid-state physics department of Siemens-Schuckert
werke, in Erlangen
, where he developed the new, III-V compounds
, to replace silicon semiconductors. His work resulted in large-scale use of galvanomagnetic and optoelectronic
effects, as well as new switching circuits in microelectronics
. Welker and his department paved the way for microwave
semiconductor
s and laser diodes. He was the director of the Erlangen Siemens-Schuckertwerke research laboratory from 1961 to 1969. From 1969, until he retired in 1977, Welker was director of all the company’s research laboratories.
While at the Westinghouse subsidiary in Paris, Welker and German physicist Herbert F. Mataré
, just months after Bell laboratory
scientists announce the demonstration of a point contact transistor in 1948, applied for a patent on the same type of device on August 13, 1948. On 18 May 1949, this European invention coined as the "Le Transistron" or the "French transistor" was presented to the public. This development was an outgrowth of work done by the two independently in Germany in programs to develop German radar
. The French patent was granted in 1952.
Welker was elected president of the Deutsche Physikalische Gesellschaft
in 1977.
Siemens AG, Munich
, in 1976 established the Heinrich Welker Memorial Award to honor Welker’s pioneering work in III-V compound semiconductor development.
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
theoretical and applied physicist
Physicist
A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...
who invented the "transistron", a form of transistor
Transistor
A transistor is a semiconductor device used to amplify and switch electronic signals and power. It is composed of a semiconductor material with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals changes the current...
made at Westinghouse independently of the first successful transistor made at Bell Laboratories. He did fundamental work in III-V compound semiconductor
Compound semiconductor
A compound semiconductor is a semiconductor compound composed of elements from two or more different groups of the periodic table . These semiconductors typically form in groups 13-16 ,...
s, and paved the way for microwave
Microwave
Microwaves, a subset of radio waves, have wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz and 300 GHz. This broad definition includes both UHF and EHF , and various sources use different boundaries...
semiconductor
Semiconductor
A semiconductor is a material with electrical conductivity due to electron flow intermediate in magnitude between that of a conductor and an insulator. This means a conductivity roughly in the range of 103 to 10−8 siemens per centimeter...
elements and laser diode
Laser diode
The laser diode is a laser where the active medium is a semiconductor similar to that found in a light-emitting diode. The most common type of laser diode is formed from a p-n junction and powered by injected electric current...
s.
Biography and important work
Starting in 1931, Welker studied at the University of Munich under Arnold SommerfeldArnold Sommerfeld
Arnold Johannes Wilhelm Sommerfeld was a German theoretical physicist who pioneered developments in atomic and quantum physics, and also educated and groomed a large number of students for the new era of theoretical physics...
, and was granted a Ph.D. in 1936. The book Electrodynamics - Lectures on Theoretical Physics Volume III by Sommerfeld was based on lecture notes prepared by Welker during the winter semester of 1933/1934. Welker was granted his Habilitation
Habilitation
Habilitation is the highest academic qualification a scholar can achieve by his or her own pursuit in several European and Asian countries. Earned after obtaining a research doctorate, such as a PhD, habilitation requires the candidate to write a professorial thesis based on independent...
under Sommerfeld in 1939.
During the war years
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
, 1940 to 1945, Welker worked at Luftfunkforschungs Institut in Oberpfaffenhofen
Oberpfaffenhofen
Oberpfaffenhofen is a village which is part of the municipality of Weßling in the district of Starnberg, Bavaria, Germany. It is 20 kilometers from the city center of Munich....
, but still maintained association (1942 to 1944) with the physicochemical institute of Klaus Clusius
Klaus Clusius
Klaus Clusius was a German physical chemist from Breslau , Silesia. During World War II, he worked on the German nuclear energy project, also known as the Uranium Club; he worked on isotope separation techniques and heavy water production...
at the University of Munich. After the war, 1947 – 1951, he took a job at the Westinghouse
Westinghouse Electric (1886)
Westinghouse Electric was an American manufacturing company. It was founded in 1886 as Westinghouse Electric Company and later renamed Westinghouse Electric Corporation by George Westinghouse. The company purchased CBS in 1995 and became CBS Corporation in 1997...
subsidiary in Paris
Paris
Paris is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...
, Compagnie des Freins et Signaux Westinghouse. From 1951 to 1961, Welker headed of the solid-state physics department of Siemens-Schuckert
Siemens-Schuckert
Siemens-Schuckert was a German electrical engineering company headquartered in Berlin, Erlangen and Nuremberg that was incorporated into the Siemens AG in 1966....
werke, in Erlangen
Erlangen
Erlangen is a Middle Franconian city in Bavaria, Germany. It is located at the confluence of the river Regnitz and its large tributary, the Untere Schwabach.Erlangen has more than 100,000 inhabitants....
, where he developed the new, III-V compounds
Compound semiconductor
A compound semiconductor is a semiconductor compound composed of elements from two or more different groups of the periodic table . These semiconductors typically form in groups 13-16 ,...
, to replace silicon semiconductors. His work resulted in large-scale use of galvanomagnetic and optoelectronic
Optoelectronics
Optoelectronics is the study and application of electronic devices that source, detect and control light, usually considered a sub-field of photonics. In this context, light often includes invisible forms of radiation such as gamma rays, X-rays, ultraviolet and infrared, in addition to visible light...
effects, as well as new switching circuits in microelectronics
Microelectronics
Microelectronics is a subfield of electronics. As the name suggests, microelectronics relates to the study and manufacture of very small electronic components. Usually, but not always, this means micrometre-scale or smaller,. These devices are made from semiconductors...
. Welker and his department paved the way for microwave
Microwave
Microwaves, a subset of radio waves, have wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz and 300 GHz. This broad definition includes both UHF and EHF , and various sources use different boundaries...
semiconductor
Semiconductor
A semiconductor is a material with electrical conductivity due to electron flow intermediate in magnitude between that of a conductor and an insulator. This means a conductivity roughly in the range of 103 to 10−8 siemens per centimeter...
s and laser diodes. He was the director of the Erlangen Siemens-Schuckertwerke research laboratory from 1961 to 1969. From 1969, until he retired in 1977, Welker was director of all the company’s research laboratories.
While at the Westinghouse subsidiary in Paris, Welker and German physicist Herbert F. Mataré
Herbert Mataré
Herbert Franz Mataré was a German physicist. The focus of his research was the field of semiconductor research. His best-known work is the first functional "European" transistor, which he developed and patented together with Heinrich Welker in the vicinity of Paris in 1948, at the same time and...
, just months after Bell laboratory
Bell Labs
Bell Laboratories is the research and development subsidiary of the French-owned Alcatel-Lucent and previously of the American Telephone & Telegraph Company , half-owned through its Western Electric manufacturing subsidiary.Bell Laboratories operates its...
scientists announce the demonstration of a point contact transistor in 1948, applied for a patent on the same type of device on August 13, 1948. On 18 May 1949, this European invention coined as the "Le Transistron" or the "French transistor" was presented to the public. This development was an outgrowth of work done by the two independently in Germany in programs to develop German radar
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...
. The French patent was granted in 1952.
Welker was elected president of the Deutsche Physikalische Gesellschaft
Deutsche Physikalische Gesellschaft
The Deutsche Physikalische Gesellschaft is the world's largest organization of physicists. The DPG's worldwide membership is cited as 60,000, as of 2011...
in 1977.
Siemens AG, Munich
Siemens AG
Siemens AG is a German multinational conglomerate company headquartered in Munich, Germany. It is the largest Europe-based electronics and electrical engineering company....
, in 1976 established the Heinrich Welker Memorial Award to honor Welker’s pioneering work in III-V compound semiconductor development.
Selected Literature
- Arnold Sommerfeld and Heinrich Welker Künstliche Grenzbedingungen beim Keplerproblem, Annalen der Physik 32 56-65 (1938) as cited in Sommerfeld Bibliography
- Arnold Sommerfeld and Heinrich Welker Über ein elektronentheoretisches Modell des Supraleiters. Mitteilung über die Arbeit., Sitzungsberichte der mathematisch-naturwissenschaftlichen Klasse der Bayerischen Akademie der Wissenschaften zu München page 5 (1938) as cited in Sommerfeld Bibliography