Crack free and spherical shape copper–zinc composite oxide thin films fabrications by AACVD

Abstract

Crack free, mesoporous and crystalline 3CuO–ZnO composite oxide thin films have been prepared by aerosol assisted chemical vapor deposition (AACVD) using the tetranuclear heterobimetallic complex [Zn(TFA)3(μ-O)Cu3(dmap)3Cl]·THF (1) (where dmap=N,N-dimethylamino-1-propanolato, TFA=trifluoroacetate and THF=tetrahydrofuran). The designed precursor 1 has been synthesized by a simple chemical reaction in high yield and characterized by its melting point, elemental analysis, FT-IR, mass spectrometry, single crystal X-ray analysis and thermal analysis (TGA/DTA). The single crystal X-ray analysis of complex 1 shows that it crystallizes in the triclinic space group P1¯ with cell dimensions a=10.617, b=10.952, c=18.713Ǻ. The TGA/DTA analysis proved that the thermal decomposition of precursor 1 at 723K gives the 3CuO–ZnO composite oxide residue. Crystalline thin films of 3CuO–ZnO composite have been fabricated by using AACVD on a glass substrate at 723K in a single step without pre or post annealing. The material properties of the deposited thin films have been characterized by X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX) and Rutherford back scattering (RBS) analysis, and the results proved that the deposited thin films are of the crystalline 3CuO–ZnO composite oxide, free from other impurities. Further exploration of the XRD data of the films proved the formation of the crystalline 3CuO–ZnO composite with an average crystallite size of 45nm, calculated from broadening by the Debye–Scherrer formula. Scanning electron microscopy (SEM) showed that the spherical-like particles have a diameter in the range of 0.2–0.5μm, sintered together to form a compact 3CuO–ZnO composite oxide thin film, and qualify the scotch tape test.