We describe the growth of GaSb/GaAs self-assembled quantum dots by MBE and also their incorporation into modulation-doped quantum well devices. The importance of the use of a valved arsenic source is also discussed. By varying the deposition thickness of the GaSb layer, it is possible to tune the emission wavelength from the dot ensemble to 1.3 mum at room temperature indicating the potential for optical communications applications. (C) 2002 Elsevier Science B.V. All rights reserved.