Blue, Green and White InGaN Light-Emitting Diodes Grown on Si

High-brightness InGaN light-emitting diodes (LEDs) have been grown on Si substrates by metal-organic vapor phase epitaxy. Both blue and green LEDs with an output power exceeding 0.7 mW and a lifetime exceeding 500 h were achieved. Two factors were analyzed: the difference between identical LED structures grown on Si and sapphire substrates, and the effect of cracking on the performance of LEDs grown on Si. Using a Si substrate, the LED emission showed a shift toward longer wavelength compared with that from a LED grown on sapphire. The presence of cracking, unless serious, showed little effect on the brightness and performance of the LEDs grown on Si. The mechanisms involved are discussed.