Zinc has been diffused into Si single crystals and estimations of the diffusion constant and solubility have been obtained by conductivity measurements. In the range 1000-1300°C the diffusivity varies between 10-6 and 10-7 cm2/sec. However, no definite trend with temperature could be established, presumably because of surface barriers on the Si. A maximum solubility of about 1.4×1017 cm-3 occurs at 1350°C and retrograde behavior is observed. Hall effect and conductivity measurements as functions of temperature have been made on Si crystals containing diffused Zn. One acceptor level only was found for Zn at 0.31 ev above the valence band. B, Ga Al, and As were used as doping impurities. The electronic levels of the doping acceptors were altered by the presence of Zn, suggesting compound formation between the acceptor atoms and Zn.