Photoluminescence study of quantum-wire arrays grown on vicinal (111)B GaAs substrate

Photoluminescence (PL) from (Al, Ga)As quantum-wire arrays grown on vicinal (111)B GaAs substrates by molecular beam epitaxy is reported for the first time. A peak at 1.826 eV is attributed to excitonic recombination in the built-in quantum-wire array, and a peak at 1.759 eV and a low PL emission band also originate from the serpentine superlattice structure. For comparison, the epilayers were also deposited on (100) GaAs substrates simultaneously. But the PL results indicate that they are the alloy-well structures. We explain these PL results with a model and draw a conclusion that steps on (111)B surface can play a very important role in crystal growth.