Self-relaxation vapor-liquid-solid growth of two-dimensional transition metal dichalcogenides with loose interface

Abstract

Engineering interfacial interactions like adhesion and strain during the growth of two-dimensional (2D) materials is of absolute importance for their properties manipulation and applications. Here, a self-relaxation vapor-liquid-solid (SRVLS) growth of 2D transition metal dichalcogenides (TMDs) is proposed and investigated through molten-precursor-mediated chemical vapor deposition (CVD) method. The liquid droplets can coordinate and balance both processes of precipitation of metal oxides and capture of chalcogens, leading the growth fronts of 2D TMDs and thus forming a contact angle between the resulted solid TMD edges and the growth substrate. On this basis, a loose interface adhesion and in-plane relaxation of strains are revealed in the as-grown TMD layers. The average work of adhesion energy of 33.7 mJ/m2 for SRVLS-grown MoS2 on SiO2 is determined according to Young–Dupré equation, which is approximately three times reduction compared to traditional vapor-solid (VS) growth. Moreover, these SRVSL growth features can be utilized for implement of curl-free delamination and reverse transfer of TMD layers onto target substrates for applications through water-dissolving the solidified droplets by only using water.