Quantum wells with atomically smooth interfaces

By a cleaved-edge overgrowth method with molecular beam epitaxy and a (110) growth-interrupt anneal, we have fabricated a GaAs quantum well exactly 30 monolayers thick bounded by atomically smooth AlGaAs heterointerfaces without atomic roughness. Microphotoluminescence imaging of this quantum well indeed shows spatially uniform and spectrally sharp emission over areas of several tens of microns in extent. By adding a fractional GaAs monolayer to our quantum well we are able to study the details of the atomic step-edge kinetics responsible for flat interface formation. (C) 2002 American Institute of Physics.