Fig. 1: Unidirectional domain alignment enabled by buffer layer control.
From: Epitaxy of wafer-scale single-crystal MoS2 monolayer via buffer layer control
Optical microscopy images of the as-grown MoS2 triangular domains under three representative MoO3/S precursor ratios: 3.9% (a), 4.5% (b) and 5.1% (c). Scale bar, 20 μm. Optical micrographs of MoS2 at different growth stages: nucleation (d), stitching (e) and coalescence of grains (f). Scale bar, 30 μm. g The degree of unidirectional alignment as a function of the MoO3/S precursor ratio. Dashed line is the curve fitted by the Gaussian function. h Schematic illustration of the buffer layer control strategy toward the synthesis of wafer-scale monolayer MoS2 single crystals. i Cross-sectional high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) images of a MoS2 grown on the c-plane sapphire substrate along the <10\(\bar{1}\)0> and <11\(\bar{2}\)0> directions. j Photograph of the as-grown full-coverage monolayer MoS2 on 2-inch c-plane sapphire substrate with a major miscut angle towards M axis.
