Journal of Crystal Growth 236 (2002) 145–154 InAs/GaAs(100) self-assembled quantum dots: arsenic pressure and capping effects B.J. Riel a,b, *, K. Hinzer a,b,1 , S. Moisa a , J. Fraser a , P. Finnie a , P. Piercy b , S. Fafard a,2 , Z.R. Wasilewski a a Institute for Microstructural Sciences, National Research Council, Building M50, Montreal Road, Ottawa, Ont., Canada K1A 0R6 b Physics Department, University of Ottawa, Ottawa, Ont., Canada K1A 6N5 Received 1 October 2001; accepted 14 December 2001 Communicated by D.W. Shaw Abstract We explore growth effects leading to size and compositional limitations in the production of self-assembled quantum dots (QD) emitting at long wavelengths. Molecular beam epitaxy grown QDs are studied as a function of arsenic pressure at a specific InAs coverage, and as a function of InAs coverage for three arsenic pressures. As a function of increasing the arsenic pressure used in QD growth, the photoluminescence (PL) of capped QDs is first redshifted at low arsenic pressures, and then blueshifted at high arsenic pressures. Microscopy of uncapped QDs shows that as the arsenic pressure increases, the QD density increases while the average QD width and height decrease monotonically; these trends are consistent with the shift in PL for the high arsenic pressure samples, but are inconsistent with the shift in PL for the low-pressure samples. This points to a modification of the QDs during capping. We discuss prior reports pertaining to arsenic pressure and capping effects, and in this context describe our observations of the effects of adjusting the arsenic pressure on the formation of QDs and the mechanism by which QDs may be modified during capping. r 2002 Elsevier Science B.V. All rights reserved. PACS: 68.37.Hk; 68.37.Ps; 68.66.Hb; 78.55.Cr; 78.67.Hc; 81.07.Ta; 81.15.Hi Keywords: A3. Molecular beam epitaxy; A3. Quantum dots; B2. Semiconducting III–V materials 1. Introduction In recent years, there has been significant interest in zero-dimensional (0D) semiconductor structures. In addition to fundamental scientific interest, there is a strong technological motivation due to the potential applications of 0D structures in better-performing or novel devices such as lasers, wavelength switches, optical memories, and quantum computers. Of all the methods for producing 0D structures in semiconductors, the *Corresponding author. Institute for Microstructural Sciences, National Research Council, Building M50, Montreal Road, Ottawa, Ont., Canada K1A 0R6. Tel.: +1-613-993-4177; fax: +1-613-941-4667. E-mail address: bruno.riel@nrc.ca (B.J. Riel). 1 Present address: Nortel Networks, Ottawa, Canada K1Y 4H7. 2 Present address: Alcatel Optronics, Gatineau, Canada J8T 8R1 0022-0248/02/$-see front matter r 2002 Elsevier Science B.V. All rights reserved. PII:S0022-0248(01)02391-0