STRUCTURE AND PHOTOLUMINESCENCE OF SINGLE ALGAAS GAAS QUANTUM DOTS GROWN IN INVERTED TETRAHEDRAL PYRAMIDS/

Arrays of single GaAs/AlGaAs quantum dot (QD) heterostructures grown b y organometallic chemical vapor deposition in inverted tetrahedral pyr amids on {111}B GaAs substrates are investigated. Cross-sectional atom ic force microscopy images evidence a pronounced thickening of the GaA s quantum well layer at the tip of the pyramid, giving rise to a lens- like QD structure. Low- temperature photoluminescence and cathodolumin escence spectra show distinct luminescence from the dots, exhibiting f illing of QD states separated by 33 meV at increased carrier densities . Luminescence linewidths of 15 meV and line energy variations of less than 5 meV are obtained across mm(2) sample areas. (C) 1998 American Institute of Physics. [S0003-6951(98)03442-1].