Structural and optical characterization of InAs nanostructures grown on high-index InP substrates

The structural and optical properties of InAs layers grown on high-index In P surfaces by molecular beam epitaxy are investigated in order to understan d the self-organization of quantum dots and quantum wires on novel index su rfaces. Four different InP substrate orientations have been examined, namel y, (1 1 1)B, (3 1 1)A, and (3 1 1)B and (1 0 0). A rich variety of InAs nan ostructures is formed on the surfaces. Quantum wire-like morphology is obse rved on the (1 0 0) surface, and evident island formation is found on (1 1 1)A and (3 1 1)B by atomic force microscopy. The photoluminescence spectra of InP (1 1 1)A and (3 1 1)B samples show typical QD features with PL peaks in the wavelength range 1.3-1.55 mu m with comparable efficiency. These re sults suggest that the high-index substrates are promising candidates for p roduction of high-quality self-organized QD materials for device applicatio ns. (C) 1999 Elsevier Science B.V. All rights reserved.