Size dependence of the work function in InAs quantum dots on GaAs(001) as studied by Kelvin force probe microscopy

摘要

We have investigated a work function of single InAs quantum dots (QDs) on GaAs(001) correlating with the dot size by means of Kelvin force probe microscopy. The observed contact potential difference (CPD) of the single QD is lower than that of an InAs wetting layer, and increases with decreasing QD height. The height dependence of the CPD is well interpreted in terms of the quantum size effect by which the amount of accumulated charges in the QD is determined through the confinement energy levels in the QD.