Oleg Vladimirovich Losev (also spelled as Lossev or Lossew) (10 May 1903 – 22 January 1942) was a prominent Russian scientist and inventor, who is known for making a number of important discoveries in the field of semiconductor junctions.
Oleg Losev failed to complete a formal education, however he was the pioneer in researching semiconductors, who published 43 papers and got 16 "author's certificates" (patents) for his discoveries. He was the first to observe light emission from carborundum point-contact junctions, the first light-emitting diode (LED) and research them. He was also the first to propose the correct theory of how they worked, and applied them in practice in electroluminescence. He studied negative resistance in semiconductor junctions, and applied his discoveries in practice to create the first solid-state amplifiers, electronic oscillators, and superheterodyne radio receivers, analogs of transistors that were invented 25 years later. Unfortunately his scientific contribution was overlooked, and was unknown for half a century until it was recognized in the late 20th century.
Career and Personal Life
Losev was born in a noble family of a retired captain in the Tsarist Imperial Army in Tver, Russia. After the revolution his father worked in the office of Tverskoy Vagonostroitelniy Zavod (Tversky Wagon Works).
Losev's noble background prevented him to enter the university after graduating from high school in 1920. So he had to work as a technician at the Nizhny Novgorod Radio Laboratory (NNRL), the first radio science laboratory in the USSR. There, in Nizhny Novgorod, Losev worked under Vladimir Lebedinsky. Although he had always been a self-taught scientist without a college education, never had a dedicated research team, and never made a scientific career, he managed to conduct innovative research. He zeroed in researching the point-contact crystal detector (cat's whisker detector), which served as a demodulator in the first radio receivers, crystal radios. Despite the fact that these crude semiconductor diodes which, in fact, were the first semiconductor electronic devices, were widely used, it was not clear how they worked. Losev specialized in this field and became one of the first semiconductor physicists in the world.
After the Nizhny Novgorod Radio Laboratory was shut down in 1928, he, together with many of the research team, moved to Leningrad (St. Petersburg) to work at the Central Radio Laboratory (CRL). From 1929 to 1933 he worked at the Ioffe Physical-Technical Institute. In 1938 he was even awarded a PhD from the Institute without completing a formal thesis, but it didn't help him make a career. Since1937 to 1942 Losev worked as a technician at the Leningrad First Medical Institute (now the First Pavlov State Medical University of St. Peterburg) which did not approve his research. Oleg Losev died of starvation in 1942, at the age of 38, during the Siege of Leningrad by the Nazi during World War II. His burial place remains unknown.
When working as a technician at Nizhny Novgorod, Losev observed biased junctions and noticed that when direct current was passing through a silicon carbide (carborundum) point contact junction, it emitted a spot of greenish light at the contact point. Losev created a light-emitting diode (LED). Although this effect had been first noticed in 1907 by British Marconi engineer Henry Joseph Round, it was Losev who first researched the effect, proposed a theory of how it worked, and foresaw its practical applications. In 1927, Losev published the article describing the details of his investigation in a Russian journal.
Losev focused on researching the mechanism of light emission. At that time, scientists considered that point contact junctions worked by a thermoelectric effect. They thought that it happened due to microscopic electric arcs. Losev found out that evaporation of benzine from the crystal surface was not accelerated when light was emitted, so he drew a conclusion that the luminescence was not caused by thermal effects but was just a "cold" light. He proposed a correct theory that the light emission could be explained by quantum mechanics, and supposed that it was the inverse of the photoelectric effect discovered by Albert Einstein in 1905. He even wrote a letter to Einstein about his theory, but did not get a reply.
From 1924 to 1941, Oleg Losev published a number of scientific articles that focused on how a solid-state light source could generate light via electroluminescence. Unfortunately at that time only Losev saw how these weak green lights could be used.
In 1951, Kurt Lehovec in his article cited Losev's papers. In the April 2007 issue of Nature Photonics, Nikolay Zheludev called Losev a person who invented the LED. Losev patented the "Light Relay" and described how it could be used in telecommunications.
When applying a DC bias voltage to a cat's whisker detector to enhance its sensitivity as a detector in a crystal radio, it sometimes breaks into oscillation that causes a radio frequency alternating current. The physicists refer to this effect as a negative resistance effect which had been noticed around 1909 by such scientists as William Henry Eccles and G. W. Pickard. However little attention had been paid to it until 1923 when Losev started researching "oscillating crystals" and found out that zinc oxide crystals could amplify a signal. Losev was also the first to use negative resistance diodes in practice. He suggested using them as simpler, cheaper replacements for vacuum tubes. He created solid-state versions of amplifiers, oscillators, and TRF and regenerative radio receivers, at frequencies up to 5 MHz, 25 years before the transistor had been invented. He even constructed a superheterodyne receiver. Unfortunately his discoveries were overlooked because at that time vacuum tube technology was commonly used. The Soviet authorities did not support his inventions, and it was rather difficult to get zincite crystals as they had to be imported from the United States.
In 1956 negative resistance in diodes was rediscovered, but this time in the tunnel diode. These days negative resistance diodes such as the Gunn diode and IMPATT diode are widely used in microwave oscillators and amplifiers and are the most frequently used sources of microwaves.