It was British Marconi engineer Henry Joseph Round who in 1907 was first to report observation of electroluminescence from the unsymmetrical passage of current through silicon carbide (carborundum) point contact junction whereby a spot of yellow to greenish light was given off at the contact point. In 1924, a Russian scientist named Oleg Vladimirovich Losev later recreated the effect but instead of just publishing a brief two paragraph note of it, went a step further by investigating the effect, proposing a theory of how it worked, and envisioned practical applications which were published in a Russian journal in 1927.
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At the time, the prevailing theory of point contact junctions was that they worked by a thermoelectric effect, possibly due to microscopic electric arcs. Losev measured rates of evaporation of benzine from the crystal surface and found it was not accelerated when light was emitted, concluding that the luminescence was a "cold" light not caused by thermal effects. He theorized correctly that the explanation of the light emission was in the new science of quantum mechanics, speculating that it was the inverse of the photoelectric effect explained by Albert Einstein in 1905. He wrote to Einstein about it, but did not receive a reply.
