Daryl Muscott Chapin (21 July 1906 – 19 January 1995) was an American physicist, best known for co-inventing
solar cells
A solar cell, also known as a photovoltaic cell (PV cell), is an electronic device that converts the energy of light directly into electricity by means of the photovoltaic effect. in 1954 during his work at
Bell Labs
Nokia Bell Labs, commonly referred to as ''Bell Labs'', is an American industrial research and development company owned by Finnish technology company Nokia. With headquarters located in Murray Hill, New Jersey, Murray Hill, New Jersey, the compa ...
alongside
Calvin S. Fuller and
Gerald Pearson. For this, 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 US patent of significant technology. Besides the Hall of Fame, it also operate ...
in 2008.
Biography
Chapin was born in
Ellensburg
Ellensburg is a city in and the county seat of Kittitas County, Washington, United States. It is located just east of the Cascade Range near the junction of Interstate 90 and Interstate 82. The population was 18,666 at the 2020 census. and was ...
,
Washington
Washington most commonly refers to:
* George Washington (1732–1799), the first president of the United States
* Washington (state), a state in the Pacific Northwest of the United States
* Washington, D.C., the capital of the United States
** A ...
on 21 July 1906, although he spent his childhood in
Salem, Oregon
Salem ( ) is the List of capitals in the United States, capital city of the U.S. state of Oregon, and the county seat of Marion County, Oregon, Marion County. It is located in the center of the Willamette Valley alongside the Willamette River, w ...
. There, he obtained his bachelor's degree from
Willamette University
Willamette University is a Private university, private Liberal arts colleges in the United States, liberal arts college with locations in Salem, Oregon, Salem and Portland, Oregon. Founded in 1842, it is the oldest college in the Western United ...
and later on received his master's from the
University of Washington
The University of Washington (UW and informally U-Dub or U Dub) is a public research university in Seattle, Washington, United States. Founded in 1861, the University of Washington is one of the oldest universities on the West Coast of the Uni ...
. Before joining
AT&T
AT&T Inc., an abbreviation for its predecessor's former name, the American Telephone and Telegraph Company, is an American multinational telecommunications holding company headquartered at Whitacre Tower in Downtown Dallas, Texas. It is the w ...
in 1930, he lectured physics at
Oregon State College
Oregon State University (OSU) is a public land-grant research university in Corvallis, Oregon, United States. OSU offers more than 200 undergraduate degree programs and a variety of graduate and doctoral degrees through all 11 of the universit ...
for a year.
Prior to working on solar cells, he worked on magnetic materials. While working on power sources for remote telephone systems in humid areas such as the tropics, where
dry cell
An electric battery is a source of electric power consisting of one or more electrochemical cells with external connections for powering electrical devices. When a battery is supplying power, its positive terminal is the cathode and its nega ...
batteries are unreliable, he investigated solar power as an energy source after considering alternatives like
thermoelectric generator
A thermoelectric generator (TEG), also called a Seebeck generator, is a solid state device that converts heat (driven by temperature differences) directly into electrical energy through a phenomenon called the '' Seebeck effect'' (a form of the ...
s and small
steam engine
A steam engine is a heat engine that performs Work (physics), mechanical work using steam as its working fluid. The steam engine uses the force produced by steam pressure to push a piston back and forth inside a Cylinder (locomotive), cyl ...
s. Initially he investigated
selenium
Selenium is a chemical element; it has symbol (chemistry), symbol Se and atomic number 34. It has various physical appearances, including a brick-red powder, a vitreous black solid, and a grey metallic-looking form. It seldom occurs in this elem ...
, getting efficiencies which were too low with a yield of about 4.9 watts per square meter.
At the same time, Pearson and Fuller were working on altering
semiconductor
A semiconductor is a material with electrical conductivity between that of a conductor and an insulator. Its conductivity can be modified by adding impurities (" doping") to its crystal structure. When two regions with different doping level ...
properties through introduction of impurities. They created a
p–n junction by dipping a
gallium
Gallium is a chemical element; it has Chemical symbol, symbol Ga and atomic number 31. Discovered by the French chemist Paul-Émile Lecoq de Boisbaudran in 1875,
elemental gallium is a soft, silvery metal at standard temperature and pressure. ...
-doped
silicon
Silicon is a chemical element; it has symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic lustre, and is a tetravalent metalloid (sometimes considered a non-metal) and semiconductor. It is a membe ...
piece in
lithium
Lithium (from , , ) is a chemical element; it has chemical symbol, symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard temperature and pressure, standard conditions, it is the least dense metal and the ...
at around 500 °C before exposing it to sunlight, hence discovering its ability to generate
photocurrent
Photocurrent is the electric current through a photosensitive device, such as a photodiode, as the result of exposure to radiant power. The photocurrent may occur as a result of the photoelectric, photoemissive, or photovoltaic effect. The phot ...
s. Pearson informed Chapin of this discovery, prompting him to switch materials and after a year the functional solar cell was demonstrated on 25 April 1954.
The solar cells delivered a power of about 60 watts per square meter, for an efficiency of 6 percent, and was patented as a "solar energy converting apparatus".
The initial discovery attracted major media attention, with the ''
New York Times
''The New York Times'' (''NYT'') is an American daily newspaper based in New York City. ''The New York Times'' covers domestic, national, and international news, and publishes opinion pieces, investigative reports, and reviews. As one of ...
'' reporting the discovery on its first page as one which "may mark the beginning of a new era, leading eventually to the realization of one of mankind’s most cherished dreams–the harnessing of the almost limitless energy of the sun for the uses of civilization". It initially failed to gain major commercialization due to its still-prohibitive costs and found only niche use in small electronic devices such as the
transistor radio
A transistor radio is a small portable radio receiver that uses transistor-based circuitry. Previous portable radios used vacuum tubes, which were bulky, fragile, had a limited lifetime, consumed excessive power and required large heavy batteri ...
. However,
the Pentagon
The Pentagon is the headquarters building of the United States Department of Defense, in Arlington County, Virginia, across the Potomac River from Washington, D.C. The building was constructed on an accelerated schedule during World War II. As ...
found use of the technology for their satellites and in 1958 launched the
Vanguard 1
Vanguard 1 (Harvard designation: 1958-Beta 2, COSPAR ID: 1958-002B ) is an American satellite that was the fourth artificial Earth-orbiting satellite to be successfully launched, following Sputnik 1
Sputnik 1 (, , ''Satellite 1''), ...
, the first solar-powered satellite.
For the discovery, Chapin was awarded an honorary doctorate by his alma mater, Willamette, and the
John Scott Medal
John Scott Award, created in 1816 as the John Scott Legacy Medal and Premium, is presented to men and women whose inventions improved the "comfort, welfare, and happiness of human kind" in a significant way. "...the John Scott Medal Fund, establish ...
from
Philadelphia
Philadelphia ( ), colloquially referred to as Philly, is the List of municipalities in Pennsylvania, most populous city in the U.S. state of Pennsylvania and the List of United States cities by population, sixth-most populous city in the Unit ...
, both in 1956. By 1959, he had simplified the solar cell's experiment to the point where it was performed by high school students across the
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...
. In order to bring down the cost, he experimented with
polycrystalline silicon
Polycrystalline silicon, or multicrystalline silicon, also called polysilicon, poly-Si, or mc-Si, is a high purity, polycrystalline form of silicon, used as a raw material by the solar photovoltaic and electronics industry.
Polysilicon is produc ...
but was unable to reproduce the efficiencies of the single crystals. He died in his home in
Naples, Florida
Naples is a city in Collier County, Florida, United States. As of the 2020 United States census, 2020 census, the population was 19,115, down from 19,539 at the 2010 census. Naples is a principal city of the Collier County, Florida, Naples–Marc ...
on 19 January 1995, at age 88. After his death, 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 US patent of significant technology. Besides the Hall of Fame, it also operate ...
in 2008 alongside his two co-workers.
References
{{DEFAULTSORT:Chapin, Daryl
1906 births
1995 deaths
20th-century American physicists
People from Ellensburg, Washington
Willamette University alumni
University of Washington alumni
20th-century American inventors
Physicists from Washington (state)