Russell Shoemaker Ohl (January 30, 1898 – March 20, 1987) was an American scientist who is generally recognized for

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 ...

ing the modern

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.

(, "Light sensitive device"). Ohl was a notable

semiconductor A semiconductor is a material which has an electrical conductivity value falling between that of a conductor, such as copper, and an insulator, such as glass. Its resistivity falls as its temperature rises; metals behave in the opposite way ...

researcher prior to the invention of the

transistor upright=1.4, gate (G), body (B), source (S) and drain (D) terminals. The gate is separated from the body by an insulating layer (pink). A transistor is a semiconductor device used to Electronic amplifier, amplify or electronic switch, switch ...

. He was also known as R.S. Ohl. Russell Ohl’s specialized area of research was into the behavior of certain types of

crystal A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macro ...

s. He worked on materials research in the 1930s at

AT&T AT&T Inc. is an American multinational telecommunications holding company headquartered at Whitacre Tower in Downtown Dallas, Texas. It is the world's largest telecommunications company by revenue and the third largest provider of mobile ...

Bell Labs Nokia Bell Labs, originally named Bell Telephone Laboratories (1925–1984), then AT&T Bell Laboratories (1984–1996) and Bell Labs Innovations (1996–2007), is an American industrial research and scientific development company owned by mul ...

’ Holmdel facility, investigating diode detectors suitable for high-frequency

wireless Wireless communication (or just wireless, when the context allows) is the transfer of information between two or more points without the use of an electrical conductor, optical fiber or other continuous guided medium for the transfer. The most ...

broadcasting Broadcasting is the distribution of audio or video content to a dispersed audience via any electronic mass communications medium, but typically one using the electromagnetic spectrum (radio waves), in a one-to-many model. Broadcasting began wi ...

, and

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. His work was only understood by a handful of scientists in the organization, one of whom was Dr.

Walter Brattain Walter Houser Brattain (; February 10, 1902 – October 13, 1987) was an American physicist at Bell Labs who, along with fellow scientists John Bardeen and William Shockley, invented the point-contact transistor in December 1947. They shared the ...

(one of the trio who invented the germanium bipolar transistor in 1947, and who would be awarded the

Nobel Prize for Physics ) , image = Nobel Prize.png , alt = A golden medallion with an embossed image of a bearded man facing left in profile. To the left of the man is the text "ALFR•" then "NOBEL", and on the right, the text (smaller) "NAT•" then " ...

in 1956). Ohl, in 1939, discovered the PN barrier (or as it became known, the “

P–N junction A p–n junction is a boundary or interface between two types of semiconductor materials, p-type and n-type, inside a single crystal of semiconductor. The "p" (positive) side contains an excess of holes, while the "n" (negative) side contai ...

”)."Silicon P-N Junction"
1999, ScienCentral Inc. and

American Institute of Physics The American Institute of Physics (AIP) promotes science and the profession of physics, publishes physics journals, and produces publications for scientific and engineering societies. The AIP is made up of various member societies. Its corpora ...

, Retrieved on October 6, 2010 At the time hardly anyone knew anything about the impurities within these crystals, but Russell Ohl discovered the mechanism by which it worked. It was the impurities which made some sections more resistant to

electric Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described by ...

al flow than others, and thus it was the "barrier" between these areas of different purity that made the crystal work. Ohl later found that super-purifying

germanium Germanium is a chemical element with the symbol Ge and atomic number 32. It is lustrous, hard-brittle, grayish-white and similar in appearance to silicon. It is a metalloid in the carbon group that is chemically similar to its group neighbors ...

was the key to making repeatable and usable semiconductor material for

diode A diode is a two-terminal electronic component that conducts current primarily in one direction (asymmetric conductance); it has low (ideally zero) resistance in one direction, and high (ideally infinite) resistance in the other. A diod ...

s. All diodes (incl. LEDs, laser diodes etc.) are descendants of Ohl's work. His work with diodes led him later to develop the first silicon solar cells.

References

External links

* -- "''Light sensitive device''"
IEEE History Center: Oral History of Russell Ohl

Oral history interview with Dr. Russell Ohl on 19 August 1976, American Institute of Physics, Niels Bohr Library & Archives
- Session I, interview conducted by Lillian Hoddeson in

Vista, California Vista (; Spanish for "view") is a city in San Diego County, California. Vista is a medium-sized city within the San Diego-Carlsbad, CA Metropolitan Area and has a population of 101,638. Vista's sphere of influence also includes portions of u ...

Oral history interview with Dr. Russell Ohl on 20 August 1976, American Institute of Physics, Niels Bohr Library & Archives
- Session II
Russell Ohl
- Longer biography at the Engineering and Technology History Wiki

{{DEFAULTSORT:Ohl, Russell 1898 births 1987 deaths

See also

References

Further reading

External links