Role of Molecular Sieves in the CVD Synthesis of Large-Area 2D MoTe2

The synthesis of high-quality 2D MoTe2 with a desired phase on SiO2/Si substrate is crucial to its diverse applications. A side reaction of Te with the substrate Si leading to SiTe and Si2Te3 tends to happen during growth, resulting in the failure to obtain MoTe2. It has been found that molecular sieves can adsorb the silicon telluride byproducts and eliminate the influence of the side reaction during the chemical vapor deposition synthesis of MoTe2. With the help of molecular sieves, few-layer 1T' MoTe2 can be grown from the MoOx precursor. Pure 1T' MoTe2 and 2H MoTe2 regions in centimeter-sized areas synthesized on the same piece of SiO2/Si substrate can be obtained by using an overlapped geometry. The strategy provides a new method to controllably synthesize MoTe2 with desired phases and can be generalizable to the synthesis of other tellurium-based layered materials.