Chapter 2 - Synthesis of 2D heterostructures

Abstract

The rise in both the structural and electronic quality of two-dimensional (2D) layered materials has opened enormous opportunities to construct van der Waals heterostructures with diverse functionalities, which were not accessible earlier in their bulk counterpart. The vertical heterointegration of diverse 2D transition metal dichalcogenides (TMDs) has been reported extensively via mechanical or chemical transfer strategies. However, the present 2D transfer methods still pose severe problems associated with interfacial contamination, stability, and scalability. On the other hand, the controlled growth of high-electronic-quality 2D heterostructures is one of the utmost challenges in the existing method, limiting the opportunity and advancement of 2D device research. This chapter covers the recent progress in the synthesis of wide varieties of 2D TMD-based heterostructures using different growth techniques and approaches. Special emphasis is placed on the growth of heterostructures in lateral and vertical configurations, accessible via cost-effective CVD strategies. Critical parameters such as stoichiometry, crystallographic orientation, grain, surface topography, domain size, and layer number must be controlled for the preparation of electronic quality 2D heterostructures. Methods to tailor their optical, electronic, and magnetic properties through phase engineering via doping, alloying, and intercalation pathways are also enlisted.