Scanning tunneling microscopy investigation of truncated InP/GaInP2 self-assembled islands

We present an investigation of the morphology of InP/GaInP three-dimensiona l (3D) islands obtained by molecular beam epitaxy. This material system sho uld represent the counterpart of the InGaAs/GaAs system for the visible ran ge. The islands are found to be truncated pyramids with observable phosphor ous-rich surface reconstruction on top. The investigation of the effect of P overpressure reveals a path to achieve extremely homogeneous 3D islands t hrough an island shape transition. These results help us understand the eme rging issue of 3D island shape transition. (C) 2000 American Institute of P hysics. [S0003-6951(00)00147-9].