STRONG LUMINESCENCE INTENSITIES IN AL0.22GA0.78AS GROWN ON MISORIENTED (111)B GAAS

Abstract

Strong enhancement in the luminescence intensity is observed in Al0.22Ga0.78As epitaxial layers grown on misoriented (111)B GaAs at 636-degrees-C. For 3-degrees misorientation, the luminescence intensity is almost 10 times that of (100) layers and the luminescence efficiency is an order of magnitude stronger than that of (100). (100) Al0.4Ga0.6As/GaAs quantum well laser diode structures grown under identical conditions with a low threshold current density of 150 A/cm2 are indications of excellent AlGaAs material quality. Electron mobility for 3-degrees misoriented (111) Al0.25Ga0.75As is about 10% higher than that for side-by-side grown (100). The strong luminescence associated with a large red shift of 90 meV, the 10% mobility enhancement, and wirelike structure shown in transmission electron microscopy are indicative of the natural formation of quantized structures.