Epitaxial growth of Cu2O and ZnO/Cu2O thin films on MgO by plasma-assisted molecular beam epitaxy

We report the epitaxial growth of Cu2O (0 0 1) and m-plane (1 0 1¯ 0) ZnO/Cu2O thin films on both bulk MgO (0 0 1) and biaxially textured thin films of MgO (0 0 1) via plasma-assisted molecular beam epitaxy. Cube on cube epitaxial growth of Cu2O thin films on both bulk MgO (0 0 1) and biaxially textured thin films of MgO (0 0 1) was observed and confirmed via X-ray diffraction and reflection high energy electron diffraction measurements. In addition, epitaxial m-plane ZnO growth via plasma-assisted MBE was conducted on both MgO substrates and Cu2O/MgO substrates. The ability to grow oriented, high-quality n-ZnO/p-Cu2O heterostructures enables improved thin film morphology and may have important implications for optoelectronic and photovoltaic devices.