Fig. 3: Wafer-scale uniformity and high quality.
From: Epitaxy of wafer-scale single-crystal MoS2 monolayer via buffer layer control
a Representative low-energy electron diffraction (LEED) patterns of a continuous MoS2 film indicating the single domain orientation nature of the MoS2 film, taken at 95 eV. b Stacked linearly polarized SHG six-petal patterns. SHG from different locations is indicated by symbols with different colors. Solid line is the fitting result to show the six-petal pattern. c, d Representative photoluminescence (PL) spectra (c) and Raman spectra (d) at 25 different locations on the wafer. Dash-dotted box highlights the PL signals from sapphire substrate. e Fluorescence microscope image of the as-grown film. A scratch has been intentionally created in the upper right corner to endow with a clear contrast between MoS2 film and bare sapphire substrate. Scale bars, 100 μm. f Polarization-resolved Raman spectra for 532 nm excitation. g The low-temperature (10 K) PL spectra of the as-grown MoS2. h Circularly polarized PL spectra of the as-grown MoS2 at 10 K, Excitation light is right-handed circularly polarized (σ+) at 1.96 eV (633 nm). i Circular polarization calculated from the PL spectra in h. The high value about 68% indicates the high quality of the MoS2 film.
