Growth and structural characterization of ZnO on Y2O3/YSZ by pulsed laser deposition

Pulsed laser deposition was used to form epitaxial Y2O3 buffer layers on yttria-stabilized zirconia (YSZ) (1 1 1) substrates, followed by formation of epitaxial ZnO. Structural characterization by X-ray diffraction, atomic force microscopy, and transmission electron microscopy (TEM) shows that Y2O3 has high-quality crystalline characteristics with a smooth (1 1 1) surface, providing a good buffer for deposition of ZnO films on YSZ. For ZnO deposition, a two-step growth process had been adopted, which consisted of low-temperature nucleation and high-temperature growth. ZnO films on Y2O3/YSZ have good structural qualities in c-axis orientation with smooth surfaces. Electron diffraction patterns show an orientation relationship of [21¯1¯0]ZnO//[01¯1]Y2O3 and (0002)ZnO//(222)Y2O3. High-resolution TEM clearly reveals that both the interfaces of ZnO/Y2O3 and Y2O3/YSZ are flat without the formation of any interlayers.