Multi color solid state led/laser

摘要

A light emitting diode (LED) grown on a substrate doped with one or more rare earth or transition element. The dopant ions absorb some or all of the light from the LED's active layer, pumping the electrons on the dopant ion to a higher energy state. The electrons are naturally drawn to their equilibrium state and they emit light at a wavelength that depends on the type of dopant ion. The invention is particularly applicable to nitride based LEDs emitting UV light and grown on a sapphire substrate doped with cromium. The chromium ions absorb the UV light, exciting the electrons on ions to a higher energy state. When they return to their equilibrium state they emit red light and some of the red light will emit from the LED's surface.