SPATIALLY-RESOLVED VISIBLE LUMINESCENCE OF SELF-ASSEMBLED SEMICONDUCTOR QUANTUM DOTS

Ensembles of defect-free lnAlAs islands of ultrasmall dimensions embed ded in AlGaAs have been grown by molecular beam epitaxy. Cathodolumine scence was used to directly image the spatial distribution of the quan tum dots by mapping their luminescence and to spectrally resolve very sharp peaks from small groups of dots, thus providing experimental ver ification for the discrete density of states in a zero-dimensional qua ntum structure. Visible luminescence is produced by different nominal compositions of ln(x)Al((1-x))As-AlyGa(1-y)As.