Growth of biepitaxial zinc oxide thin films on silicon (100) using yttria-stabilized zirconia buffer layer

In this work, an approach for integrating zinc oxide thin films with Si(100) substrates using an epitaxial tetragonal yttria-stabilized zirconia buffer layer is reported. Selected area electron diffraction measurements revealed the following epitaxial relationship: $[110]YSZ∥[100]Si$ and $(001)YSZ∥(001)Si$⁠. X-ray diffraction studies demonstrated that subsequent growth of the zinc oxide thin film on the yttria-stabilized zirconia buffer layer occurred with the following epitaxial relationship: $(0002)ZnO∥(001)YSZ$⁠. The full width at half maximum value for the (0002) peak of zinc oxide was small $(∼0.16°)$⁠, which indicated good crystalline quality. Transmission electron microscopy revealed that the zinc oxide thin film grew epitaxially on an yttria-stabilized zirconia buffer layer in two different orientations, where one orientation was rotated by $30°$ from the other. The orientation relationship in this case was $[101¯0]ZnO∥[100]YSZ$ or $[21¯1¯0]ZnO∥[100]YSZ$ and $(0002)ZnO∥(001)YSZ$⁠. The biepitaxial growth of the zinc oxide thin film has been explained in the framework of domain matching epitaxy. Optical emission measurements showed a strong excitonic emission peak from the zinc oxide thin film at $∼377nm$⁠. Minimal green band emission in the photoluminescence spectrum indicated that the concentration of point defects was low. Integration of epitaxial zinc oxide thin films with Si(100) substrates is an important step toward developing practical applications of zinc oxide in a variety of optoelectronic devices.