Improvement of optical properties of air-exposed regrowth interfaces embedded in InAs quantum dots and GaAs/AlGaAs quantum wells by atomic hydrogen

We report an atomic hydrogen cleaning effect on surface oxide and contaminants on airexposed interfaces embedded in GaAs quantum well (QW) and InAs quantum dot (QD). A partly grown GaAs QW and a GaAs buffer layer for InAs QDs were airexposed and hydrogen cleaned. After this procedure, we directly regrew a GaAs QW and InAs QDs as an active layer. Removal of surface oxide was monitored by reflection high-energy electron diffraction. The cleaned surface showed beta(2 x 4) reconstruction. The photoluminescence properties of GaAs/AlGaAs QWs and InAs/GaAs QDs showed no degradation compared with those of the reference samples, even though the air-exposed interfaces were included in the active regions.