Bis-3-methylpyridine and bis-4-methylpyridine complexes of cadmium(II) ethylxanthate have been characterized by elemental analysis, NMR spectroscopy, and thermogravimetric analysis. The single crystal X-ray structures of both methylpyridine derivatives have also been determined and shown to display a cis, cis, cis-configuration of the N-and S-donor ligands. The compounds have been utilized as single source precursors to deposit CdS films on silica-coated glass substrates at 220 and 350 °C by aerosol-assisted chemical vapor deposition. The surface morphology of the films has been examined by scanning electron microscopy analysis and the crystalline phases were studied by powder X-ray diffraction. The films deposited from the 3methylpyridine adduct comprised more densely packed and more highly crystalline hexagonal CdS than those provided by either of the other two precursors. The crystallite sizes were found to be <20 nm for films deposited from the pyridine and 4methylpyridine adducts but to display a dimension of ca. 30 nm when deposited from the 3-methylpyridine precursor. Despite these differences in morphology and crystalline composition, the electronic properties of all the CdS films were deduced by UV− vis spectroscopy to be very similar and to display absorption behavior and band gaps (E g = 2.25−2.40 eV) consistent with bulk CdS.

We report the development of a true single source precursor for the growth of zirconia thin films by aerosol-assisted chemical vapour deposition using an original family of zirconium(iv) amidate derivatives.

Sunlight is the ultimate source of energy on Earth. Although the photovoltaic (PV) effect remains the most promising means to convert sunlight directly to useable electricity, current devices are dominated by crystalline silicon solar cells. While a mature technology, the indirect band gap of silicon means that the light absorption coefficient is low (102 cm-1) and thick layers (100-500 μm) are needed to absorb the requisite number of photons to produce the necessary efficiencies. The cost associated with the production of the thick layers of silicon needed to meet the increasing supply demand is, thus, very high. To date, the supply of sufficient high purity silicon has been economical due to the electronics industry, which produces large amounts of high purity silicon waste. This economic benefit will start to be eroded, however, should the silicon solar sector to continue to grow. To this end, materials containing post-transition metals with an ns 2 electronic configuration (e.g. Pb 2+ , Sn 2+ , Ge 2+ , Sb 3+ and Bi 3+) are attracting significant recent attention for their solar absorber ability. 1 A case in point is provided by tin(II) monosulfide (SnS), which possesses a high absorption coefficient (>104 cm-1) and a near ideal direct band gap of ca. 1.3 eV. 2 Although these properties, in conjunction with the high relative abundance of both tin and sulfur, denote SnS as an attractive candidate photovoltaic absorber, the efficiency of SnS-based devices has yet to reach 5% indicating that significant further advances in materials processing and thin film deposition methods will be required if this promise is to be fulfilled. 3-5 SnS thin films have been deposited by ALD, 6, 7 spray pyrolysis, 8-13 sputtering, 14-16 chemical bath deposition, 17-29 vacuum evaporation, 30-35 and CVD. 11, 36-49 In this latter regard, an initial report by Price et al. described the use of atmospheric pressure (AP) CVD to deposit a variety of tin sulfide stoichiometries from SnCl4 and H2S in the temperature range 300-545 °C, 36, 38 albeit SnS was only obtained at 545 °C. Similarly, (fluoroalkylthiolato)tin(IV) and organotin(IV) dithiocarbamates have been reported to provided SnS under APCVD conditions with the addition of H2S. 39, 44, 46 The tin thiolate precursor, (PhS)4Sn, has also allowed SnS deposition in the temperature range 350-500 ºC both with and without the presence of H2S by aerosol-assisted (AA) CVD. 40, 41 All the deposited films were amorphous, although Raman spectroscopy and EDX analysis confirmed the presence of tin sulfide. O'Brien and co-workers subsequently described a range of organo tin(IV) and Sn(II) dithiocarbamates, for example the diethyldithiocarbamate derivatives 1 and 2, which were suitable