Improvements in MBE Grown AlxGa1-xAs/GaAs Single Quantum Well Structures Resulting from Dimeric Arsenic

The effect of arsenic species on the photoluminescent response of GaAs/Al x Ga 1- x As single quantum well structures grown by molecular beam epitaxy was studied. At high substrate temperatures, e.g. 700°C, the luminescent properties were not highly sensitive to the arsenic species (dimeric or tetrameric) used. At lower substrate temperatures, however, the As species had a significant influence on the response. With a substrate temperature of 620°C, the intensity of the photoluminescence peak due to the quantum well increased by a factor of 2.5 in going from As 4 to As 2 , primarily as a result of an improved inverted heterointerface. One proposed mechanism of improvement, the more effective cracking of arsenic at high substrate temperatures, is supported by these results.