Semiconducting nanostructured copper sulfide thin films from bidentate copper(ii) complexes of N-(dialkylcarbamothioyl)-nitrosubstituted benzamides by chemical vapour deposition

Abstract

Copper(II) complexes of various N-(dialkylcarbamothioyl)-nitrosubstituted benzamide [dialkyl = di-n-butyl (1a, 2a); hexyl, methyl (3a); butyl, ethyl (4a)] have been synthesized and characterized by elemental analysis, IR spectroscopy and atmospheric pressure chemical ionization-mass spectrometry (MS-APCI). The molecular structure of the complex 2a was determined by single-crystal X-ray diffraction. These complexes were used as single-source precursors for the deposition of copper sulfide thin films by aerosol assisted chemical vapour deposition (AA-CVD) at 350 °C. The powder X-ray diffraction (p-XRD) patterns of the thin films of complexes 3a and 4ashowed the deposition of rhombohedral digenite Cu₉S₅ phase, and complex 1a deposited monoclinic roxbyite Cu₇S₄ phase at 350 °C with spherical crystallites. Complex 2a deposited orthorhombic anilite Cu₇S₄ phase with spherical crystallites. The degree of roughness of the film surface was determined by atomic force microscopy (AFM). The scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDXA) results showed the uniform distribution of copper sulfide in the films, which makes them useful semiconducting materials on a structured surface.