Shape and Orientation Controlled Hydrothermal Synthesis of Silicide and Metal Dichalcogenide on a Silicon Substrate

Shape-controlled MoS₂ has been grown directly on a silicon substrate, for the first time, with the use of a facile hydrothermal synthesis approach. The growth morphology is dependent on the substrate orientation. Square, hexagonal, and triangular patterns of MoS₂ are grown on Si(100), Si(110), and Si(111), respectively. Detailed studies reveal that Mo silicide is formed at the initial stage, and the formation of silicide patterns is dictated by the different surface energies of Si(100), Si(110) and Si(111). Subsequently, shaped MoS₂ patterns are formed following the silicide ones at the thermodynamic equilibrium. The approach for the formation of these patterns can be generalized to other 2D materials and can also be formed on a large scale by a lithography method. The work has shown a new technique to form silicide via solution processing and grow patterned 2D materials directly on silicon substrates, which may have the potential for advancing next-generation electronic devices.