Raman line scan analysis. (a) Optical image, the line scan was performed on the black line indicated. (b) Contour plot with phonon modes indicated. (c) Relative intensity of the E12g phonon peak with standard error indicated. The measurements and analysis show a good uniformity for the deposited bilayer GaS. The relative intensity of the E12g peak is shown to present a standard error of only 2.5% across an area spanning 100 μm.