Growth and emission tuning of InAs/InP quantum dots superlattice

We report the solid source molecular beam epitaxial growth of InAs/InP quan tum dot (QD) superlattices and the effect of As/P exchange on the interface between InAs and InP. The InAs QDs were found to have an average lateral d iameter of similar to 40nm and a density of 3-4 x 10(9)cm(-2). The QDs supe rlattice has photoluminescence (PL) emission centred at 0.77eV with a linew idth of 64meV at low temperature (4K). X-ray diffraction (XRD) spectra show ed evidence of significant As/P exchange on the interface between InAs and InP during in situ annealing under Pt pressure before growing the spacer la yer of InP. An average P composition of similar to 30% in the resulting InA sP QDs in samples: annealed for 50s was deduced from dynamical simulations of the experimental XRD spectra. The QDs superlattice PL emission exhibits a blueshift following an increase in annealing time, and emission at 1.55 m um and at 300K was achieved. This observation holds promise for possible te lecommunication device applications at long wavelengths. (C) 2001 Elsevier Science B.V. All rights reserved.