Light-emitting diode superior for illumination in terms of color rendering, whereas one cannot appreciate the color of red or green objects illuminated only by the yellow (and remaining blue) wavelengths from the YAG phosphor. The first white LEDs were expensive and inefficient. However, the light output of LEDs has increased exponentially, with a doubling occurring approximately every 36 months since the 1960s (similar to Moore's law). The latest research and development has been propagated by Japanese manufacturers such as Panasonic, Nichia, etc. and later by Korean and Chinese factories and investment such as: Samsung, Solstice, Kingsun, and countless others. This trend is
Light-emitting transistor made of indium gallium phosphide, indium gallium arsenide, and gallium arsenide, and emitted infrared photons from the base layer. Light-emitting transistor A light-emitting transistor or LET is a form of transistor that emits light. Higher efficiency than light-emitting diode (LED) is possible. Reported in the January 5, 2004 issue of the journal Applied Physics Letters, Milton Feng and Nick Holonyak, the inventor of the first practical light-emitting diode (LED) and the first semiconductor laser to operate in the visible spectrum, made the world's first light-emitting transistor. This hybrid device, fabricated by Feng's graduate student Walid Hafez, had one electrical input