Influence of the size of self-assembled InAs/AlAs quantum dots on photoluminescence and resonant tunneling

Self-assembled InAs quantum dots (QDs) grown on AlAs have been embedded in three sample structures for atomic force microscopy (AFM), photoluminescence (PL) and resonant-tunneling measurements. The amount of deposited InAs was varied between nominally 1.6 and 2 monolayers. This leads to a shift of the QD-related PL peak from about 1.9 to View the MathML source that is due to an increasing QD size as confirmed by AFM images of the reference wafer. With increasing InAs coverage, the onset voltage for single-electron tunneling shifts from 0.3 to View the MathML source which is explained by the lower lying ground state in the larger QDs. The observed strong dependence of the QD size on the InAs coverage offers up a simple way to adjust the onset voltage for single-electron tunneling via growth parameters.