Molecular precursors for the electrodeposition of 2D-layered metal chalcogenides.

Two-dimensional transition metal dichalcogenides (TMDCs) are highly anisotropic, layered semiconductors, with the general formula ME (M = metal, E = sulfur, selenium or tellurium). Much current research in this field focusses on TMDCs for catalysis and energy applications; they are also attracting great interest for next-generation transistor and optoelectronic devices. The latter high-tech applications place stringent requirements on the stoichiometry, crystallinity, morphology and electronic properties of monolayer and few-layer materials. As a solution-based process, wherein the material grows specifically on the electrode surface, electrodeposition offers great promise as a readily scalable, area-selective growth process. This Review explores the state-of-the-art for TMDC electrodeposition, highlighting how the choice of precursor (or precursors), solvent and electrode designs, with novel 'device-ready' electrode geometries, influence their morphologies and properties, thus enabling the direct growth of ultrathin, highly anisotropic 2D TMDCs and much scope for future advances.