.. appliances like TVs, radios, telephones, calculators, and watches. LED cost efficiency was improved in the mid-1970s by Fairchild Optoelectronics. The team there employed compound semiconductor chips that were fabricated using the ...
.. going in was impractical. The silicon carbide used in the cat’s-whisker detectors at the time was an indirect bandgap semiconductor, and thus inefficient (the light produced was faint at best). In 1955, Rubin Braunstein of the ...