Tunneling emission from self-organized In(Ga)As∕GaAs quantum dots observed via time-resolved capacitance measurements

The observation of tunneling emission of electrons and holes from In(Ga)As∕GaAs quantum dots in time-resolved capacitance measurements is reported. The electron and hole ground-state localization energies are determined as (290±30)0.3em0exmeV and (210±20)0.3em0exmeV, respectively. These energies are in excellent agreement with predictions from eight-band k∙p theory. Based on the localization energies, we estimate the escape time for thermal excitation at room temperature as ~2000.3em0exns for electrons and ~0.50.3em0exns for holes in case of a zero-electric-field situation. The electric-field dependence of the tunneling emission is investigated in detail.