Electronic structure and transport properties of doped CoSi single crystal

The lattice parameter and electronic structures of CoSi and CoSi1−xYx (Y=Al and P, x=0.03125 and 0.125) were calculated using the full-potential linear augmented plane wave approach based on density functional theory. The calculated lattice parameter of binary CoSi is about 0.27% smaller than the experimental value. Calculated electronic structures show that CoSi is a semimetal and its density of states is very small at the Fermi level. Doping with Y on the Si site can tune the Fermi level and the effective masses as well as the density of the hole carriers or electron ones in the electronic structure of CoSi, which is a valuable way to modulate the transport properties of this compound. Based on the calculated electronic structures and our experimental results on CoSi, the intrinsic relations between the electronic structures and transport properties of doped and undoped CoSi are discussed in detail.