Enhanced optical properties of InAs/GaAs quantum dots grown by radio-frequency hydrogen plasma-assisted molecular beam epitaxy

Abstract

Strong enhancement of photoluminescence (PL) efficiency has been observed in a GaAs/InAs quantum dots-in-a-well structure, grown with in situ irradiation of atomic hydrogen supplied by a radio-frequency hydrogen plasma source. The PL enhancement and wavelength position at room temperature have been found to be stable under extensive thermal annealing up to 630 degrees C in vacuum. As shown by the corresponding improvement of the barrier material, the possible mechanism for PL enhancement is the reduced nonradiative recombination in the barrier region by in situ passivation of defects while they are generated.