A class of single-source precursors to titanium disulfide films. Synthesis, structure, and chemical vapor deposition studies of [TiCl4(HSR)2

Abstract

Titanium disulfide is one of the desirable cathode materials for lithium batteries. Recent emphasis on the development of thin-film batteries has underscored the need for high-purity, crystallographically oriented, stoichiometric coatings. The majority of chemical vapor deposition (CVD) routes of TiS[sub 2] films are based on the reaction between titanium tetrachloride and hydrogen sulfide, organic sulfides, or disulfides. Recently we reported a new atmospheric pressure CVD process for TiS[sub 2] films, which relies upon the reaction of titanium tetrachloride with organothiols at temperature [ge]200 [degrees]C and affords highly pure, crystallographically oriented, stoichiometric, adhesive coatings[sup 5]. It was envisaged the use of a single-source precursor in the deposition of TiS[sub 2] films could provide precise control of titanium and sulfur stoichiometry, could reduce toxic/odiferous waste, and would eliminate the problem of mixing two or more gaseous reactants in a low-pressure CVD reactor. However, no such precursor had been described in the literature. Herein the authors report the synthesis of the first class of single-source precursors to high quality TiS[sub 2] films. These complexes are of the formula [TiCl[sub 4](HSR)[sub 2]] and are obtained upon treatment of titanium tetrachloride with alkanethiols. Significantly, the crystallographic orientation of the films produced from these precursors ismore » ideal for use as cathodes in lithium batteries.« less