ABSTRACT
I. Introduction Nitride semiconductors of AlGaInN are suitable for light emitting diodes (LEDs) covering colors from violet to amber, because of their wide bandgap and direct-transition band structure. Excellent uniform epitaxial layers of GaN could be grown on sapphire substrates using an A1N buffer layer by metalorganic vapor phase epitaxy (MOVPE)I . We started studies on the improvement of light extraction efficiency early on, and we succeeded in developing flip chip type LEDs2. Furthermore we developed short wavelength flip chip type LEDs, "TG PURPLE Hi", and light source with this LED chip.
