Capacitance spectroscopy of InAs self-assembled quantum dots embedded in aGaAs/AlAs superlattice

The characteristics of the InAs self-assembled quantum dots embedded both i n a GaAs bulk matrix and in a GaAs/AlAs superlattice were investigated. Evi dences of electrons confinement inside the InAs quantum dots were obtained using both capacitance-voltage measurements and Raman spectroscopy. A much stronger electron localization was detected for the quantum dots embedded i n the superlattice in comparison with those embedded in bulk GaAs. As a con sequence, the electrical characteristics of the structures with quantum dot s grown in superlattices were found to be significantly thermo-stabilized. The origins of these effects are discussed in connection with the differenc es between the electronic features of the two kinds of structures. (C) 2000 American Institute of Physics. [S0021-8979(00)01116-6].