Porotech has developed a way to fabricate red, green and blue microLEDs on a single GaN epi wafer. Some approaches use special structure to fabricate RGB microLEDs on a single GaN wafer (NS Nanotech and Nanosys/Glo), but Porotech uaes a third technique. According to the company, their materials processing is such to allow heavy In doping of the GaN wafer to reach red wavelengths. The current drive to any individual microLED can then change the color from blue to green to red. To get gray scale, they then use pulse width modulation.
