Growth and properties of wide bandgap (MgSe)n(ZnxCd1−xSe)m short-period superlattices

We report the molecular beam epitaxy (MBE) growth and properties of (MgSe)n(ZnxCd1−x Se)m short-period superlattices(SPSLs) for potential application in II-VI devices grown on InP substrates. SPSL structures up to 1 µm thick with effective bandgaps ranging from 2.6 eV to above 3.42 eV are grown and characterized, extending the typical range possible for the ZnxCdyMg1−x−ySe random alloy beyond 3.2 eV. Additionally, ZnxCd1−xSe single and multiple quantum well structures using the SPSL barriers are also grown and investigated. The structures are characterized utilizing reflection high-energy electron diffraction, X-ray reflectance, X-ray diffraction and photoluminescence. We observed layer-by-layer growth and smoother interfaces in the QWs grown with SPSL when compared to the ZnxCdyMg1−x−ySe random alloy. The results indicate that this materials platform is a good candidate to replace the random alloy in wide bandgap device applications.