최초의 실용적인 가시광선 스펙트럼 주도의 was invented in 1962. This device, based on a Gallium Arsenide Phosphide (GaAsP) 반도체 substrate, emitted red light at a wavelength of approximately 650 nm. While its initial efficiency was low, it was the first LED bright enough for practical use, launching the industry of solid-state indicators and displays like those in early calculators.

















