We deposited an AlGaAs/GaAs quantum well (QW) structure by MOCVD on [0 1 1]-aligned pyramids on (1 0 0) semi-insulating GaAs substrate. The pyramids were either flat-top or blade-sharp. They were confined at the sides by facets A and B were tilted to (1 0 0) at similar to 30 degrees and similar to 45 degrees, respectively. The AlGaAs/GaAs QW structure overgrew the pyramids continuously. Facets A were fast-growing and facets B were slow growing. The TEM cross-sectional observation showed the GaAs QW layer on facets B was similar to 10 nm thick. AFM analysis showed that overgrown facets A were rougher than facets B (RMS similar to 20 nm). A photoluminescence signal corresponding to e1 -hh1 transition in QW, with full width at half maximum of 17.6 meV, was detected. (C) 2010 Elsevier B.V. All rights reserved.