  Kagome metals AV3Sb5 (A = K, Rb, and Cs) exhibit a unique superconducting
ground state coexisting with charge-density wave (CDW), whereas how these
characteristics are affected by carrier doping remains unexplored because of
the lack of an efficient carrier-doping method. Here we report successful
electron doping to CsV3Sb5 by Cs dosing, as visualized by angle-resolved
photoemission spectroscopy. We found that the electron doping with Cs dosing
proceeds in an orbital-selective way, as characterized by a marked increase in
electron filling of the Sb 5pz and V 3dxz/yz bands as opposed to relatively
insensitive nature of the V 3dxy/x2-y2 bands. By monitoring the temperature
evolution of the CDW gap around the M point, we found that the CDW can be
completely killed by Cs dosing while keeping the saddle point with the V
3dxy/x2-y2 character almost pinned at the Fermi level. The present result
suggests a crucial role of multi-orbital effect to the occurrence of CDW, and
provides an important step toward manipulating the CDW and superconductivity in
AV3Sb5.
