#In the history of LEDs, the Soviet Union once played a pioneering role, but now it no longer holds the position it once had (Russia). Why is that?

In the story of LEDs (light-emitting diodes), the Soviet Union played a role marked by tragedy and a unique technological path. This history can be summarized as: a theoretical prophet, a practical laggard, and a distinctive 'yellow light' technological route.

1. 1920s: The Forgotten 'Prophet' Losev

At the beginning of the LED story, the Soviet scientist Oleg Losev was a true pioneer, but his work was buried by the times.
Oleg Vladimirovich Losev (1903–1942) lived a life that is a typical tragedy of a 'genius buried by his era.' Without a formal university degree, he came from a background of self-taught amateur science yet independently discovered the principle of the LED. He quietly passed away during the Siege of Leningrad from hunger and cold, and his contributions were not recognized by the world until decades later.

Losev was born into a noble family of the Russian Empire but lived in turbulent times, which made the start of his life full of obstacles.

• A life of upheaval: Born in 1903 in Tver (some sources say Nizhny Novgorod), his father was an officer in the Tsar's army. After the October Revolution, being of noble lineage became a burden. Although he completed secondary education, due to his family background and the chaos of war, he never gained access to university training, which remained a lifelong regret.
• Starting as a 'messenger': In 1920, he joined the Nizhny Novgorod Radio Laboratory (NNRL). Due to his low educational level, he initially could only work as a messenger and lab assistant (menial tasks), at times so poor that he slept on the staircases of the laboratory. Yet, through incredible self-learning ability and with the recognition of the famous physicist Vladimir Lebedinsky, he began engaging in core radio research.

Despite his humble status, Losev exhibited remarkable creativity in the 1920s, making two discoveries worthy of historical record.

1. Discovery of LED (Electroluminescence): Around 1924, while debugging silicon carbide (SiC) crystal detectors, he keenly noticed the faint green light at the junctions. Unlike his predecessors who ignored it, he systematically studied its spectrum and threshold and published a paper in 1927, naming it the "luminous silicon carbide detector." He correctly pointed out that it was “cold light” (non-thermal radiation) and even applied for a patent for a "photo relay," predicting the use of LEDs in optical communication.
2. Invention of the "crystal oscillator" (Crystodyne): He also discovered the negative resistance effect in certain crystals (such as zinc oxide) and created the world's earliest solid-state semiconductor amplifier. This was more than 20 years earlier than the transistor and was praised as the "transistor before the transistor."

Ironically, because semiconductor theory was not yet mature and his status was low, these achievements were ignored within the Soviet Union and went unheard of internationally.

After the 1930s, Loschev's situation took a sharp downturn, and fate was particularly cruel to him.

• Academic discrimination: Although he was unusually awarded the degree of Candidate of Sciences (similar to a PhD) in 1938, he was never able to obtain a formal professorship. In 1937, he was forced to leave the Physical-Technical Research Institute and moved to the Physics Department of the First Leningrad Medical Institute as an ordinary technician, completely detached from frontline scientific research.
• Tragic end: In 1941, Nazi Germany besieged Leningrad (St. Petersburg). During the 872-day siege, Loschev, along with millions of citizens, was plunged into desperate conditions. On January 22, 1942, this scientist who had once tried to transmit information with light starved to death in the cold, at only 38 years old. His remains were never found and most likely were hastily buried in a mass grave.

2. Cold War Period: Taking a "Detour"

When the United States launched efficient infrared and red LEDs in the 1960s based on gallium arsenide (GaAs), the Soviet Union chose a different technological path.

• Material Choice: The Soviet research system (represented by the Ioffe Institute of Physics and Technology) was not behind in research on III-V compounds (such as GaAs), but when it came to LED industrialization, it largely adopted the silicon carbide (SiC) route from the Loschev era.
• Unique "Soviet Yellow": In the 1970s-80s, the mainstream LEDs in the West were red and green (GaAsP/GaP), while the Soviet Union produced a large number of silicon carbide yellow LEDs (such as the common КИПД series). These LEDs had very low luminous efficiency (very dim) and high driving voltage, but they were widely used in military and industrial equipment due to their unique stability.
• Cutting-edge Microdisplays: The Soviet Union had its own expertise in military/aerospace electronics. For example, the famous К490ИП1 (K490IP1) micro LED display integrated counters and decoders, was extremely small (about 2.5mm), and was widely used in aircraft instruments and military equipment. It remains a collectible among vintage electronics enthusiasts today.

3. Outcome: From Glory to Silence

• Military Supply: The Soviet LED industry mainly served defense and aerospace (such as aircraft dashboards and missile indicators), with almost no presence in the civilian market. This meant that while the technology was reliable, it was expensive, and brightness stagnated for a long time.
• Missing the Lighting Revolution: In the 1980s-90s, when Japan and the United States achieved breakthroughs in gallium nitride (GaN) blue LEDs (which directly led to white LEDs and the lighting revolution), the Soviet Union completely missed this wave of technological advancement due to economic collapse and interruptions in research. Russia's LED industry did not restart in aerospace and other specialized fields until after 2000.

Summary

The Soviet Union's role in the history of LEDs was mixed:

• High starting point: It had theoretical geniuses like Lossev.
• Path dependency: During the Cold War, it stubbornly adhered to the silicon carbide route, missing the wave of high-efficiency III-V compound (gallium arsenide, gallium nitride) LEDs.
• Legacy: It left behind a large number of robust and durable yellow LEDs and microdisplays in metal packages with a strong 'Soviet aesthetic,' becoming a unique spectacle in electronic archaeology.