Phase-selective in-plane heteroepitaxial growth of H-phase CrSe2.

Phase engineering of two-dimensional transition metal dichalcogenides (2D-TMDs) offers opportunities for exploring unique phase-specific properties and achieving new desired functionalities. Here, we report a phase-selective in-plane heteroepitaxial method to grow semiconducting H-phase CrSe₂. The lattice-matched MoSe₂ nanoribbons are utilized as the in-plane heteroepitaxial template to seed the growth of H-phase CrSe₂ with the formation of MoSe₂-CrSe₂ heterostructures. Scanning tunneling microscopy and non-contact atomic force microscopy studies reveal the atomically sharp heterostructure interfaces and the characteristic defects of mirror twin boundaries emerging in the H-phase CrSe₂ monolayers. The type-I straddling band alignments with band bending at the heterostructure interfaces are directly visualized with atomic precision. The mirror twin boundaries in the H-phase CrSe₂ exhibit the Tomonaga-Luttinger liquid behavior in the confined one-dimensional electronic system. Our work provides a promising strategy for phase engineering of 2D TMDs, thereby promoting the property research and device applications of specific phases. Phase engineering of 2D transition metal dichalcogenides enables the investigation of emerging physical properties. Here, the authors report a phase selective in-plane heteroepitaxial method to grow semiconducting H-phase CrSe₂ thin films from MoSe₂ nanoribbons, showing Tomonaga-Luttinger liquid behaviour in the CrSe₂ mirror twin boundaries. [ABSTRACT FROM AUTHOR]