Electron and hole levels of InAs quantum dots in a GaAs matrix

Photoluminescence, capacitance-voltage and transmission electron microscopy studies have been carried out on structures containing a sheet of a self-a ssembled InAs quantum dots formed in GaAs matrices after the deposition of a 1.7 ML of InAs at 480 degrees C. The use of n- and p-type GaAs matrices a llows us to study separately electron and hole levels in the quantum dots b y the capacitance-voltage technique. From analysis of photoluminescence and capacitance-voltage measurements it follows that the quantum dots have ele ctron levels 80 meV below the bottom of the GaAs conduction band and two he avy-hole levels at 100 meV and 170 meV above the top of the GaAs valence ba nd. (C) 1999 Academic Press.