Synthesis of NixZn1-xO thin films by dip-coating

ALASTUEY, PATRICIO; MARIN, OSCAR; CARRILLO, MIGUEL ANGEL; COMEDI, DAVID; TIRADO, MONICA

Nara City

Simposio; 23th International Symposium on Metastable, Amorphous and Nanostructured Materials: ISMANAM 2016; 2016

WPI Advanced Institute for Materials Research, Tohoku University, SENDAI, JAPAN

Transparent conductive oxides (TCO) have extensive technological applications, due to the combination of two, in principle, exclusive physical properties: transparency in the visible region and high conductivity. Applications of these materials include UV light sensors, transparent electrodes for solar cells, displays and chemical sensors, among others. ZnO can be considered one of the most important TCO; this material has a bandgap of 3.3 eV, an electron binding energy at room temperature of 60 meV. The formation of stable solid solutionsbetween ZnO and ions of transition metals has been an interesting way to improve the physical properties of ZnO. In particular, the inclusion of Ni+2 attracts great attention due to electrical and magnetic properties of the Ni+2. The optimization of the physical properties of is important due to the broad range of applications of these materials, including catalysis, solar cell electrodes, LEDs, etc.The ZnO oxide and their derivatives can be synthesized by wet routes, where the SolGel technique is presented as the best option because of its scalability, reproducibility and fine control of the properties of the materials from the fabrication conditions. This technique generally involves the deposition of a film on a substrate through various methods, such as drop-coating, spin-coating and dip-coating. For rectangular substrates, dip-coating is the technique that allows greater homogeneity of the films. In this work, we present the synthesis of NixZn1-xO thin films by dip-coating and the optical and structural characterization of the films obtained. For the synthesis of NixZn1-xO, dihydrate zinc acetate was used as zinc precursor, hexahydrated nickel chloride was used as nickel precursor, ethanol as solvent and dimethylamine as stabilizer. Films were deposited on silicon substrates and were annealed in a tubular furnace at different times and atmospheres. They were later characterized by Photoluminescence, Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDX) and X-Ray Diffraction (XRD). The relative content of Zn, Ni and O in the films was estimated by EDX measurements; the SEM microscopy evidences the nanostructured nature of the films and the PL experiments shows that both UV and green emission depends on Ni content. A lineal dependency in the thickness of the films fabricated with the number of immersions in the precursor solution was observed.