Atomic scale study of InAs/GaAs heteroepitaxy

The initial growth layer and the island formation of InAs on GaAs are investigated for growth physics and device applications. The InAs layers are grown on the (001)-oriented GaAs substrates at 480 degrees C by molecular beam epitaxy. At and just after the growth transition from a two-dimensional mode to a three-dimensional mode, a single molecular layer of InAs on the GaAs substrate remains. Thus, the heteroepitaxy of InAs/GaAs is confirmed as Stranski-Krastanov growth. The InAs islands were proposed to be utilized as mesoscopic structures from which enhanced luminescence is emitted. It is proved that the luminescence is caused by quantum effects of the islands. These are observed and measured by atomic force microscope, transmission electron microscope, photocurrent spectroscopy, polarized photoluminescence, and electroluminescence.