On June 25, 1946, the U.S. patent office approved an application from Bell Labs for a silicon solar cell invented by Russell S. Ohl, which became U.S. Patent No. US2,402,662A, “Light sensitive device.” It was one of more than 130 inventions patented by Ohl in the U.S. and elsewhere over the years, and it helped turn solar energy from a theory into a reality.
It has been said that “Victory has a thousand fathers while defeat is an orphan,” and this is certainly true when it comes to determining who deserves credit for inventing the solar cell. Several patents were issued in the late 19th century for various solar energy inventions, and so some claim these are the true inventors but early solar cells had energy conversion efficiencies of under one percent, meaning, they proved that energy could be generated from the rays of the sun, but not efficiently enough for any kind of practical use. It would take 76 years for Russell Ohl to make his breakthrough discovery involving the use of silicon in solar cells.
Russell Shoemaker Ohl was born January 30, 1898, in Macungie, Pennsylvania, near Allentown. His wife Ruth Livingood Ohl hailed from Macungie as well, and was valedictorian of her high school class. They knew one another from a very early age.
Ohl attended Pennsylvania State College from 1914-1918, graduating with a degree in electro-chemical engineering. Seniors in the electrical engineering school could take a U.S. Army Signal Corps class, on vacuum tubes. This was the start of a lifelong fascination with radio for Ohl.
After graduation, Ohl went to Fort Monmouth (then called Camp Vail), and served with the Signal Corps until the war’s end, attending and graduating from Officer Candidate School as a second lieutenant.
While at Fort Monmouth, Ohl first began experimental work on silicon semiconductors. He was assigned to a very dangerous task, doing various radio and telegraph tests on airplanes in flight. He piloted a Curtiss JN-4H, known as the “Jenny H,” a two-seat advanced trainer biplane with ailerons on both wings. Ohl noticed that there were problems with the engine’s electrical insulators and he experimented and was able to improve engine performance through better insulators.
After the war’s end, Ohl was discharged, and began working for the Electric Storage Battery Co. of Philadelphia, where he was assigned to the development of a 320-volt battery to operate the Signal Corps Radio telephone transmitter on airplanes, SCR-68. After nine months, he left, believing his working environment there to be unsafe. He hired on with the Westinghouse Lamp Company in Bloomfield, N.J., where he had the opportunity to work with leading figures in radio science such as Edwin Armstrong. In 1921, he married Ruth, and then took a job teaching physics at the University of Colorado, where he continued his experiments with silicon conductors. In 1922, the Ohls moved to The Bronx, where they lived on Andrews Avenue for five years while Russell worked in the research department for AT&T at 195 Broadway.
The Ohls Move to Little Silver
In 1927, Russell Ohl was transferred to AT&T’s Bell Labs facility in Cliffwood, near Matawan. The Ohls moved into a home on Woodbine Avenue near Cross Street in the Foxwood Park neighborhood of Little Silver. Over the years, the Ohls made a number of real estate transactions involving lots in their immediate neighborhood, all transactions carrying a sale price of one dollar.
In an interview long after his retirement, Russell Ohl noted that fellow Bell Labs researcher Karl Janksy, who is credited with the discovery that radio signals emanate from outer space, car-pooled to work with Ohl, and eventually moved into the house next door.
Russell and Ruth were very active in their community. Russell was elected to the Little Silver board of education in 1932 and was secretary of the Little Silver PTA; Ruth also served as secretary to the PTA and the local Republican Women’s Club. They were both avid photographers, with Ruth serving as president of the Monmouth Camera Club for a time, succeeded in that role by Russell. Ruth won numerous awards and prizes for her photography. The couple had two children, Silvia Frederika Ohl, and Russell Livingood Ohl, who served as a pilot in World War II, the Korean War, and the Vietnam War; R.L. Ohl had a son, Russell Hoagland Ohl, who became a helicopter pilot in the Air Force, and was killed in action during a rescue mission on January 15, 1985.
Ohl’s specialized area of research was the behavior of certain types of crystals. In January of 1930, Ohl was moved into the new Bell Labs Holmdel facility, where he worked on materials research, focusing on diode detectors suitable for high-frequency wireless, broadcasting, and military radar. His work was at such a high level it was only understood by only a handful of scientists in an organization rife with scientific geniuses of every type.
In 1939, Ohl discovered the “P – N junction,” relating to the effects of impurities within crystals used as electrical resistors. At the time, hardly anyone knew anything about the impurities within these crystals, but Russell Ohl discovered that it was the impurities which made some sections more resistant to electrical 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 was the key to making repeatable and usable semiconductor material for diodes. The internal politics of Bell Labs was such that Ohl later said of his discovery, “contrary to the laboratories’ publicity, I found that all by myself.”
Ohl once described his process for scientific discovery thusly:
I think that science is an art and I think it comes from the artistic talents that we had naturally…My scientific talents depend largely on images; I picture everything in my mind as a picture, not on a piece of paper. I can translate that from my mind by taking wires and putting them together and that’s something most of the engineers could not do.
Ohl also said he was less of a genius and more “just a bull-headed Dutchman, that’s all.”
During World War II, Ohl changed his career focus from electrochemistry to radio. He said, “They came from all over the world to visit me in my laboratory to find out the latest in the research results.” There was tremendous pressure on him to constantly be generating new findings, being awarded new patents:
In that period, from ‘33 on, everybody, so many people, hundreds of people, would come down to my laboratories and expect to see something new each time. In order to stay in research, you have to be able to produce. So it created quite a challenge and I used to spend most of my time thinking about these things and doing all kinds of out of the way experiments.
But these experiments often involved dangerous chemicals, and Ohl’s work with tetrachloride and cyanide had a poisonous effect on him; in 1939 he suffered “a very severe nervous breakdown.”
In 1947, the Ohls moved to a new house at 9 Brookside Avenue on the corner of Linden Drive in the River Oaks neighborhood of Fair Haven. The house was described as “of modern design, has six rooms, photographer’s dark room, game room fireplace, automatic heat, screened porch and slate roof.” Russell became active in the Monmouth Boat Club during this time. In 1947 the Ohls sold the Woodbine Ave. house.
Other scientists at Bell Labs advanced Ohl’s technology, resulting in the first practical silicon photovoltaic cell in 1954. And in 1955, a trio of Bell Labs’ scientists – Gerald Pearson, Calvin Fuller and Daryl Chapin – created a solar panel made of super-skinny strips of silicon for a phone company in Georgia; many might say that was the real invention of solar technology because it was the first solar cell that could power an electric device for several hours.
The Legacy of Russell S. Ohl
Over his lifetime, Ohl was granted 82 U.S. patents and another 50 patents in other countries. There is no dispute that all solar energy cells and panels today are built on the breakthrough research of Russell S. Ohl. Likewise, all diodes, including light-emitting diodes (LEDs), laser diodes, etc., have resulted from Ohl’s work.
The direct, indirect, and implied economic impact of Russell Ohl’s inventions is incalculable, but according to various industry research projections, the size of the global solar energy industry will grow anywhere from USD$194.75 billion to $243.95 billion by 2027. The global market for LED lighting was estimated at around $USD 76 billion in 2020 and is projected to grow to $160 billion by 2026.
Russell Ohl retired in 1958, and he and Ruth moved to Cambria, California, where they remained for the remainder of their lives. The couple’s son, Russell L. Ohl Jr., and his family, lived in Vista, while the couple’s daughter Sylvia lived in San Francisco. The senior Ohl continued scientific experiments including using electrodes to study the “central nervous system” of plants.
Russell S. Ohl died March 20, 1987, aged 89, in Vista, Calif.; he and Ruth are buried in their hometown in Macungie, Pa.
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