Stable operation of AlGaAs/GaAs light-emitting diodes fabricated on Si substrate

An AlGaAs/GaAs LED (light-emitting diode) with very small degradation is fabricated in an UCGAS (undercut GaAs on Si) structure for the first time. The 43 K photoluminescence data show that the stress in UCGAS annealed at 400°C is reduced to less than 1×10 8 dyn/cm 2 . The output power from the UCGAS LED under a constant current of 800 A/cm 2 degrades to 94% of the original value in the first several hours and subsequently maintains constant output for more than 1000 hours. On the other hand, the output power emitted from the conventional mesa-type LED which contains residual stress of more than 10 9 dyn/cm 2 degrades quickly.