Abstract: A semiconductor structure includes a substrate which may be formed from a ZnS single crystal of wurtzite (2H) structure with a predetermined crystal orientation, and which has a first surface and a second surface. The structure includes a layer of a group III-nitride crystalline material deposited as an epitaxial layer on the first surface of the substrate. In one embodiment, the group III-nitride deposit is epitaxially grown using a MOCVD (or MOVPE) technique or a HVPE technique or a combination thereof. There may be a mask and/or a buffer layer on the first surface and/or a protective layer on the second surface.