Oleg Losev, a Soviet radio technician, built the first LED in 1922 at age 18. His discovery of cold light emission from carborundum crystals preceded the rest of the world by 25 years. Despite correctly identifying it as a quantum mechanical effect and predicting applications in optical communications, Losev remained a technician throughout his life. His background as the son of a Tsarist Army captain blocked academic advancement in the Soviet system.

Losev's more significant breakthrough came with negative resistance in zincite crystals. By 1924, he built solid-state radios that defied Ohm's Law. Hugo Gernsback featured his Crystodyne device in Radio News, declaring it could replace vacuum tubes. The technology proved too finicky to scale, and Losev abandoned research after a decade. His work was independently rediscovered in 1957 with the tunnel diode.

Losev received a belated doctorate in 1938 when the Ioffe Physical-Technical Institute waived thesis requirements for his 43 published papers. He refused to abandon his equipment during the Siege of Leningrad and died of starvation in 1942 at age 38. His manuscript describing a three-electrode semiconductor device was lost in wartime mail. Five years later, Bell Labs invented the transistor, forever changing electronics.