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

Strong enhancement in the luminescence intensity is observed in Al0.22 Ga0.78As epitaxial layers grown on misoriented (111)B GaAs at 636-degr ees-C. For 3-degrees misorientation, the luminescence intensity is alm ost 10 times that of (100) layers and the luminescence efficiency is a n order of magnitude stronger than that of (100). (100) Al0.4Ga0.6As/G aAs quantum well laser diode structures grown under identical conditio ns with a low threshold current density of 150 A/cm2 are indications o f excellent AlGaAs material quality. Electron mobility for 3-degrees m isoriented (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 struct ure shown in transmission electron microscopy are indicative of the na tural formation of quantized structures.