Synthesis and Characterization of Single Source Precursors for the Aerosol-assisted Chemical Vapour Deposition of Transition Metal Sulphide Nanoparticles

Abstract

A series of crystalline nickel, cadmium, mixed metal nickel/cadmium and manganese O-n- butylxanthate bis(pyridine) complexes , [Ni(S2COnBu)2.(C5H5N)2] (1), [Ni(S2COnBu)2.(3-Br- C5H4N)2] (2), [Ni(S2COnBu)2.(4-CN-C5H4N)2] (3), [Ni(S2COnBu)2.(3-Me-C5H4N)2] (4) [Ni(S2COnBu)2.(3-Cl-C5H4N)2 (5) [Cd(S2COnBu)2.(C5H5N)2] (6), [Cd(S2COnBu)2.(3-Cl- C5H4N)2 (7) [Mn(S2COnBu)2.(C5H5N)2] (8) and [Ni/Cd(S2COnBu)2.(C5H5N)2] (9), have been synthesized by simple chemical reaction. All the complexes were characterized by their melting points, elemental analyses, proton NMR, thermo gravimetric analyses and their structures were determined by single crystal X-ray analyses. Thermogravimetric analyses show that all precursors undergo facile thermal decomposition at moderate temperature to give NiS, CdS, Ni-CdS and MnS. These precursors were used for deposition of thin films of metal sulphides by Aerosole Assisted Chemical Vapour Deposition (AACVD). All the films deposited from these precursors were crystalline in nature and displayed substrate dependent morphology. Phase purity, particle size, thickness and elemental composition of thin films were determined by X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and atomic force microscopy (AFM). The size of the nanoparticles deposited from these precursors was in the range of 43-58 nm2 which was dependent on thermal behaviour of each of the complex. Thin films of MnS could not be deposited from precursor (8) as it was non volatile and unsuitable for AACVD. High purity Ni-Cd mixed metal sulphide thin films were successfully grown from single source precursor (9) for various technological applications.