Three-color integration of rare-earth-doped GaN thin films may now be possible for use in flat panel displays. Using a combination of shadow-masking and photoresist-liftoff techniques, Don Lee and Andrew Steckl, researchers at the University of Cincinnati, have laterally combined green-emitting GaN:Er and red-emitting GaN:Eu films on the same substrate. The films were electronically stimulated through circular Schottky electrodes fabricated by indium-tin oxide sputtering. The figure above shows the two films during the shadow-mask phase of production.

The researchers expect that the technique, which was reported in the March 18 issue of Applied Physics Letters, may be extended to incorporate a blue-emitting, rare-earth-doped GaN thin film -- such as GaN:Tm -- to produce red-green-blue displays.