Two-dimensional ZnO–NiO macroporous arrays: Fabrication, structure and electrical properties

Colloidal templating and pulsed laser deposition were combined to fabricate arrays of ordered two-dimensional macroporous ZnO–NiO thin films. The underlying principles involved in the formation of colloidal templates were investigated using Fourier transformations and radial distribution functions. The macroporous thin film consists of hollow half-spheres of nanocrystalline wurtzite ZnO and rock salt NiO. The electrical properties of macroporous ZnO–NiO thin films were investigated by impedance and DC current–voltage measurements. The electrical properties are controlled by the interfaces between oxide grains. The potential applications such as gas sensors and optics are discussed.