Robert Noel Hall (December 25, 1919 – November 7, 2016) was an American engineer and applied physicist. He demonstrated the first

semiconductor laser The laser diode chip removed and placed on the eye of a needle for scale A laser diode (LD, also injection laser diode or ILD, or diode laser) is a semiconductor device similar to a light-emitting diode in which a diode pumped directly with e ...

and invented a type of

magnetron The cavity magnetron is a high-power vacuum tube used in early radar systems and currently in microwave ovens and linear particle accelerators. It generates microwaves using the interaction of a stream of electrons with a magnetic field while ...

commonly used in

microwave ovens A microwave oven (commonly referred to as a microwave) is an electric oven that heats and cooks food by exposing it to electromagnetic radiation in the microwave frequency range. This induces polar molecules in the food to rotate and produce th ...

. He also contributed to the development of rectifiers for power transmission.

Biography

Robert N. Hall was born on December 25, 1919, in

New Haven, Connecticut New Haven is a city in the U.S. state of Connecticut. It is located on New Haven Harbor on the northern shore of Long Island Sound in New Haven County, Connecticut and is part of the New York City metropolitan area. With a population of 134 ...

. He was first inspired by his inventor uncle, who showed him the wonders of small inventions and experimentation. After long studies at his local library, Hall decided to attempt controlled experiments of his own with his mother's approval. He built an 8-inch telescope, which produced a close-up view of Saturn. Later on, an interviewer from the

California Institute of Technology The California Institute of Technology (branded as Caltech or CIT)The university itself only spells its short form as "Caltech"; the institution considers other spellings such a"Cal Tech" and "CalTech" incorrect. The institute is also occasional ...

visited him and offered a scholarship to attend the university. Hall studied there for three years but had to leave for financial reasons. After working at Lockheed Aircraft as a tester, he returned to Caltech to finish up his studies and obtain his physics degree. Then General Electric hired him as a test engineer at Schenectady, NY. After four years at G.E., under the advice of Harper North, Hall obtained a Research Council Fellowship and returned to Caltech. He graduated in 1948 with his Ph.D. and returned to G.E. Schenectady research labs that summer. While at G.E. during World War II, he developed a

for radar jamming, which led to the development of the

microwave oven A microwave oven (commonly referred to as a microwave) is an electric oven that heats and cooks food by exposing it to electromagnetic radiation in the microwave frequency range. This induces polar molecules in the food to rotate and produce ...

. While studying the characteristics of p-i-n diodes used as power rectifiers, Hall had a key insight, which resulted in his being co-credited with

William Shockley William Bradford Shockley Jr. (February 13, 1910 – August 12, 1989) was an American physicist and inventor. He was the manager of a research group at Bell Labs that included John Bardeen and Walter Brattain. The three scientists were jointl ...

and W. T. Read, Jr., for the analysis of nonradiative carrier recombination in semiconductors. Hall developed the first semiconductor

laser diode The laser diode chip removed and placed on the eye of a needle for scale A laser diode (LD, also injection laser diode or ILD, or diode laser) is a semiconductor device similar to a light-emitting diode in which a diode pumped directly with e ...

in 1962, while working at

General Electric General Electric Company (GE) is an American multinational conglomerate founded in 1892, and incorporated in New York state and headquartered in Boston. The company operated in sectors including healthcare, aviation, power, renewable en ...

Schenectady, New York Schenectady () is a city in Schenectady County, New York, United States, of which it is the county seat. As of the 2020 census, the city's population of 67,047 made it the state's ninth-largest city by population. The city is in eastern New Y ...

. In the 1970s, Hall's work focused on

photovoltaics Photovoltaics (PV) is the conversion of light into electricity using semiconducting materials that exhibit the photovoltaic effect, a phenomenon studied in physics, photochemistry, and electrochemistry. The photovoltaic effect is commercially ...

and

solar cell A solar cell, or photovoltaic cell, is an electronic device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon.

s. He retired in 1987, having been granted 43 U.S.

patent A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an enabling disclosure of the invention."A ...

s during his career. Hall was elected to the

National Academy of Engineering The National Academy of Engineering (NAE) is an American nonprofit, non-governmental organization. The National Academy of Engineering is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of ...

in 1977 and to the National Academy of Sciences in 1978. He was inducted into the

National Inventors Hall of Fame The National Inventors Hall of Fame (NIHF) is an American not-for-profit organization, founded in 1973, which recognizes individual engineers and inventors who hold a U.S. patent of significant technology. Besides the Hall of Fame, it also oper ...

in 1994. Robert was a Methodist and he died on November 7, 2016, at the age of 96. Death notice published by Hall's family.

Biography

References

Further reading