It is so often the case with a particular technological advance, that it will be invented almost simultaneously by more than one engineer or scientist. People seem to like a convenient tale of a single inventor, so one such person is remembered while the work of all the others who trod the same path is more obscure. Sometimes the name we are familiar with simply managed to reach a patent office first, maybe they were the inventor whose side won their war, or even they could have been a better self-publicist.
When there are close competitors for the crown of inventor then you might just have heard of them, after all they will often feature in the story that grows up around the invention. But what about someone whose work happened decades before the unrelated engineer who replicated it and who the world knows as the inventor? They are simply forgotten, waiting in an archive for someone to perhaps discover them and set the record straight.
Meet [Oleg Losev]. He created the first practical light-emitting diodes and the first semiconductor amplifiers in 1920s Russia, and published his results. Yet the world has never heard of him and knows the work of unrelated American scientists in the period after the Second World War as the inventors of those technologies. His misfortune was to born in the wrong time and place, and to be the victim of some of the early twentieth century’s more turbulent history.
[Oleg Losev] was born in 1903, the son of a retired Russian Imperial Army officer. After the Russian Revolution he was denied the chance of a university education, so worked as a technician first at the Nizhny Novgorod Radio laboratory, and later at the Central Radio Laboratory in Leningrad. There despite his relatively lowly position he was able to pursue his research interest in semiconductors, and to make his discoveries.
When experimenting with a point-contact semiconductor junction on silicon carbide and zinc oxide crystals, he observed a greenish light emission from the junction. This had been observed before but not characterised, and he was able to prove that it was not a thermal effect before postulating that it might have its source in a quantum mechanism.
He continued to work on the effect, but because of the chosen semiconductor materials he was unable to significantly increase its light output. Without enough intensity to rival other lamps of the day it failed to attract enough interest despite his publishing multiple papers detailing his work and its applications. It was left to [Robert Baird] and [Gary Pittman] at Texas Instruments in the 1960s to pick up the baton with their infra-red LED, and for [Nick Holonyak] at General Electric to produce one with visible light shortly afterwards.
Semiconductor Amplifiers And More
The detectors in many radio receivers of the day were simple “Cat’s Whisker” devices, point contact diodes where the junction was formed between a piece of wire and a naturally occurring crystal. It had been noticed that when a DC bias was used with these devices to overcome their forward voltage drop and make them more sensitive, it could occasionally cause the circuit to oscillate. [Losev] became interested in this phenomenon, and identified it as negative resistance, a semiconductor property whereby the curve has a region that behaves opposite to Ohm’s Law with current through it decreasing as voltage increases.
He was able to make reliable negative resistance diodes using zinc oxide crystals, and to configure them as oscillators and amplifiers in the same way as we might now with a more recent tunnel diode. As well as oscillators and amplifiers he created solid state radio receivers, both regenerative and superhetrodyne, several decades before [John Bardeen], [William Shockley], and [Walter Brattain] invented the first transistor at Bell Labs in 1948.
The Soviet authorities did not see the potential in this most exciting of inventions because [Losev]’s diodes could not replicate the performance of the tubes of the day, so given that the zinc oxide crystals were an expensive import from the USA the project was shelved. It was left to [Leo Esaki] at Sony in 1957 to rediscover negative resistance diodes with his discovery of electron tunneling, for which he later received a Nobel Prize.
[Losev]’s tale is a succession of moments of what might have been. He found himself trapped in Leningrad, now St. Petersburg, when it was besieged by the Germans in 1942, and like many others in the city he died of starvation. It is reported that before his death he was working on a three-terminal semiconductor amplifier device, which might have delivered the transistor to the Soviets years before it was invented by the Americans.
If [Losev]’s story has interested you, have a look at our profile of another largely unsung hero of early electronics: [Rufus Turner].