GaN based light-emitting diode on silicon (LEDoS) micro-displays for BLU-free full-color projector application

In this paper, we review the design and fabrication of GaN based light emitting diode on silicon (LEDoS) micro-displays with red, green blue and UV colors by integrating monolithic LED micro-arrays and active matrix substrates using flip-chip technology. A silicon complementary metal-oxide-semiconductor (CMOS) active matrix driving scheme was designed to provide sufficient drive capability and individual controllability of each LED pixel. The LEDoS micro-displays had 30×30 and 60×60 pixels on each single chip with pixel pitch of 140μm and 70μm and corresponding diameters of 100μm and 50μm. LEDoS micro-displays with emission wavelengths of 630nm, 535nm, 445nm and 380nm were fabricated. By integrating the red, green and blue LEDoS chips using a trichroic prism and a projection lens, the world´s first full-color 3-LEDoS projector prototype has been demonstrated.