Figure 2
(a,b) HRXRD curves of samples grown under light-start and dark-start conditions, respectively. From bottom to top the Xe lamp power increased from 0 W to 150 W. Fringes between the GaAs and ZnSe peaks disappeared with increasing Xe lamp power in the light-start samples, indicating diffusion at the interface. The fringes remained clear in all dark-start samples, indicating the presence of an abrupt interface. (c,d) Tilt-view SEM images of the light-start sample grown under a lamp power of 150 W as well as a dark reference sample. The yellow curves display a first derivative of the image contrast profile at the ZnSe/GaAs interface. The contrast profile is sharp at the interface of the dark reference sample.
