Growth of ZnSnN 2 by Molecular Beam Epitaxy

The Zn-IV-N 2 family of materials represents a potential earth abundant element alternative to conventional compound semiconductor materials that are based on gallium and indium. While both ZnSiN 2 and ZnGeN 2 have been studied to some degree, very little is known about the narrow-gap member ZnSnN 2 . Here, we investigate the growth dynamics of crystalline ZnSnN 2 through plasma-assisted molecular beam epitaxy. All films exhibit some degree of crystalline order regardless of growth conditions, although significant tin coverage was observed for films grown with low Zn:Sn flux ratio; Zn flux in particular became increasingly problematic at increased substrate temperatures designed to improve crystallinity. Single-crystal material was achieved through careful optimization of growth parameters. Regardless of deposition conditions or substrate choice, however, all films exhibit a monoclinic structure as opposed to the predicted orthorhombic lattice; this can be directly attributed to sublattice disorder.