COMPOSITION AND STRAIN OF SELF-ASSEMBLED (IN,GA,AL)SB (GA,AL)AS QUANTUM DOTS/

Quantum dots of InSb, GaSb, and AlSb were grown on GaAs by molecular b eam epitaxy and characterized by atomic force microscopy (AFM), photol uminescence, and Raman spectroscopy. AFM measurements reveal that InSb morphology can be a function of the initial GaAs surface reconstructi on. Photoluminescence measurements demonstrate that strain and confine ment effects result in a type-II band alignment for InSb quantum dots, with electrons in the GaAs and holes in the InSb. Raman spectra revea l phonon modes from quantum dots of GaSb, AlSb, and InSb, and indicate the segregation of Ga into AlSb. (C) 1997 Academic Press Limited