Ellipsometry on monolayer films of InAs and AlAs embedded in GaAs and of InP embedded in GaP

Ellipsometric measurements have been made at room temperature on MOVPE-grown InAs monolayers (M). (0.5-1 ML) and AlAs MLs (1 to 12 ML) in GaAs around the GaAs fundamental gap E0(GaAs) and on MOVPE-grown InP MLs (0.5-1 ML) in GaP around the GaP direct gap. Due to the introduction of monolayer films, the optical properties of the host material are strongly modified as a function of the monolayer material and thickness and as a function of the substrate misorientation. The perfection of the steplike monolayerrhost material interfaces has been examined by high-resolution transmission electron microscopy (HRTEM). To our knowledge the modifications of the optical properties of the system InP in GaP have been observed only by ellipsometric measurements.