Luminescence properties of as-grown and annealed InGaAs quantum dots on cross-hatch patterns

InGaAs quantum dots (QDs) grown on cross-hatch (CH) pattern of InGaAs/GaAs exhibit two fundamental luminescence peaks associated with the QD and the CH layers. The as-grown sample exhibits stronger QD luminescence due to QDs's better crystallinity. Upon hydrogen annealing, the QD peak is found to reduce while the CH peak gains in strength. This is most likely due to hydrogen termination of dangling bonds at the substrate/CH layer interface. The termination neutralizes the defects, making them ineffective as carrier traps and improving the CH layer's optical properties. This in turn has an unexpected, undesirable effect of reducing QD luminescence efficiency.