Formation of self-assembled InAs 3D islands on GaAs (1 10) substrate by metal organic vapor phase epitaxy has been investigated. Relatively uniform InAs islands with an average areal density of 10(9) cm(-2) are formed at 400 degrees C using a thin InGaAs strain reducing (SR) layer. No island formation is observed without the SR layer. Island growth on GaAs (I 10) is found to require a significantly lower growth temperature compared to the more conventional growth on GaAs (10 0) substrates. In addition, the island height is observed to depend only weakly on the growth temperature and to be almost independent of the V/III ratio and growth rate. Low-temperature photoluminescence at 1.22 eV is obtained from the overgrown islands. (C) 2007 Elsevier B.V. All rights reserved.