ARPES data of MBE grown MoSe\(_2\) with a monolayer, b bilayer, c trilayer, and d 8-layer thicknesses. The left and right most panels show the theory calculations for monolayer and 8-layer, respectively. Orange and light blue arrows indicate direct band gap from K to K point and indirect band gap from \(\varGamma\) to K point, respectively. Two top panels above a and d are the conduction band minimums for monolayer and 8-layer, respectively, which is brought down in energy by the chemical potential shift through surface potassium doping. One need to note, however, the surface doping may also modify the band structure. The figure is rearranged from the same data set used for Ref.