Dissolution-precipitation growth of uniform and clean two dimensional transition metal dichalcogenides

Abstract

Two-dimensional (2D) transition metal dichalcogenides (TMDCs) have attracted much interest and shown promise in many applications. However, it is challenging to obtain uniform TMDCs with clean surfaces, because of the difficulties in controlling the way the reactants are supplied to the reaction in the current chemical vapor deposition (CVD) growth process. Here, we report a new growth approach called “dissolution-precipitation” (DP) growth, where the metal sources are sealed inside glass substrates to control their feeding to the reaction. Noteworthy, the diffusion of metal source inside glass to its surface provides a uniform metal source on the glass surface, and restricts the TMDC growth to only a surface reaction while eliminates unwanted gas-phase reaction. This feature gives rise to highly-uniform monolayer TMDCs with a clean surface on centimeter-scale substrates. The DP growth works well for a large variety of TMDCs and their alloys, providing a solid foundation for the controlled growth of clean TMDCs by the fine control of the metal source.

Synthesis of Ultrahigh‐Quality Monolayer Molybdenum Disulfide through In Situ Defect Healing with Thiol Molecules

“…[ 10 ] Among all these methods, chemical vapor deposition (CVD) has been considered as a promising method as it provides a relatively scalable and controllable way for growing TMDCs. [ 11–21 ] Current CVD method usually uses solid (such as metal oxides and sulfur powder) as precursors for the growth of TMDCs. However, due to the significant differences of vapor pressure between sulfur and metal oxides, the reaction usually needs precise control of temperature and pressure in order to achieve stable supply of precursors, leading to poor controllability and reproducibility.…”

Chemical Vapor Deposition Growth of Two-Dimensional Compound Materials: Controllability, Material Quality, and Growth Mechanism

“…Recently, our group reported a dissolution-precipitation (DP) growth method to control the metal precursor, and obtained uniform monolayer TMDCs over the whole centimeter-scale substrate (Figure 3a). 12 Different from the traditional CVD process (Figure 3c), in the DP growth method, the metal precursor was first buried in a confined space between a piece of top thin and another piece of bottom thick glass. The metal precursor then diffused to the surface of the upper glass where it served as a reactant to grow TMDCs at high temperature.…”

Recent progress about 2D metal dichalcogenides: Synthesis and application in photodetectors

“…In a typical CVD system, the metal oxide and sulfur precursor share the same diffusion path which leads to the reaction both in the transmitting process and on the substrate, causing pollution on surface of the as-grown products. Many efforts have been done to solve this problem [77,80]. Inspired by the graphene growth method [81,82], carbon source is dissolved in the bulk or sub-surface of substrates like Cu or Ni, carbon atoms are precipitated on substrate surface to generate largearea uniform graphene.…”

“…Inspired by the graphene growth method [81,82], carbon source is dissolved in the bulk or sub-surface of substrates like Cu or Ni, carbon atoms are precipitated on substrate surface to generate largearea uniform graphene. Cai et al [77] reported a "dissolutionprecipitation" (DP) growth method that achieved the dissolution of the required metal source into the glass substrate and succeeded in growing uniform monolayer transition metal dichalcogenides (TMDs). As shown in Fig.…”