Side and top views of the two arrangements of germanene/silicene on MoS2. (a, c) Top site configuration; (b, d) hollow site configuration. Ge/Si, Mo, and S atoms are represented by blue, purple, and yellow balls, respectively. The unit cells are shown by dashed lines.
Li et al. Nanoscale Research Letters 2014 9:110 doi:10.1186/1556-276X-9-110