A full color display comprising a red, a green, and a blue light emitting
diode, each light emitting diode including a light emitting region having
at least one layer of single crystal rare earth material, the rare earth
material in each of the light emitting diodes having at least one
radiative transition, and the rare earth material producing a radiation
wavelength of approximately 640 nm in the red light emitting diode, 540
nm in the green light emitting diode, and 460 nm in the blue light
emitting diode. Generally, the color of each LED is determined by
selecting a rare earth with a radiative transition producing a radiation
wavelength at the selected color. In cases where the rare earth has more
than one radiative transition, tuned mirrors can be used to select the
desired color.