Control of II-VI/III-V heterovalent interfaces with light

In-situ light stimulation can provide an additional parameter to control semiconductor epitaxy along with well-known parameters such as growth temperature and V/III ratio. However, the influence of light on the properties of II-VI/III-V interfaces has not been investigated. Using ZnSe/GaAs as a model system, we probe the mechanisms of light-stimulated heterovalent interface formation by molecular beam epitaxy. X-ray diffraction, scanning electron microscopy, atomic force microscopy, and photoluminescence measurements reveal that UV light irradiation during interface initiation enhances As desorption and promotes additional Ga-Se related bonding at the ZnSe/GaAs interface. In moderation, the Se coverage passivates the interface and improves emission from the GaAs epilayer. Light stimulation also allows the ZnSe epilayer to be grown at lower temperatures to prevent excessive atomic interdiffusion. These results suggest that low temperature growth accompanied by UV light irradiation can be used to control intermixing at the ZnSe/GaAs interface [1].
[1] Kwangwook Park and Kirstin Alberi, Sci. Rep. 7 8516 (2017).