SUBMONOLAYER AND SUPERMONOLAYER OF INAS QUANTUM-WELLS GROWN ON GAAS BY MOLECULAR-BEAM EPITAXY

Submonolayer and supermonolayer quantum wells (QWs) of GaAs/InAs/GaAs structure were successively grown at 500 degrees C by molecular beam epitaxy and the thickness of QWs was controlled by referring the growth time of a preliminary grown layer having the critical thickness (1.85 ML). The peak energy of the photoluminescence of QWs coincides well with the calculated results carried out under the assumption of virtual crystal approximation. In case of QWs, of which well thickness just gets over the critical thickness, InAs islands of various size are formed on InAs monolayer and the fluctuation of the islands size obeys to Gaussian distribution.