said by aurgathor:Blue LEDs from the 1960s?!?
... August 1989, Cree Inc. introduced ... SiC LEDs
Yes, several researchers managed to make crude "blue-ish" LEDs in the 1960s, but they were not brought to market. Vassily Tsvetkov finally produced "commercial" grade blue LED at Siemens ... in 1977!
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Injected Light Emission of Silicon Carbide Crystals
K. LEHOVEC, C. A. ACCARDO, AND E. JAMGOCHIAN
Signal Corps Engineering Laboratories, Fort Monmouth, New Jersey
(Received April 5,
1951)
I. INTRODUCTION
SOME
silicon carbide crystals emit "cold" light while current passes. 1-7 Two types have been reported : (a) a
bluish light and (b) a yellow light, the type emitted depending on the direction of current flow.
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