The segregation of Ga during the growth of Czochralski-Si crystals with Ge codoping was investigated. The effective segregation coefficient of Ga in Ga/Ge-codoped Si crystal growth was nearly constant over a wide Ge concentration range, even at high Ge concentrations of about 10(21) cm(-3). In contrast, the effective segregation coefficient increased at high B concentrations in Ga/B-codoped CZ-Si crystal growth. The segregation behavior of Ga in Ga/Ge- and Ga/B-codoped CZ-Si crystal growth was theoretically compared. The difference in the segregation coefficients of Ga as a function of the codoped impurity (Ge or B) between the two Si crystals was attributed to a difference in the excess enthalpy due to impurity incorporation into the Si crystal between Ga-Ge pairs and Ga-B pairs The effect of Ge codoping on the minority carrier lifetime in Ga/Ge-codoped a-Si crystals was also investigated. The minority carrier lifetime increased with increasing Ge concentration. The higher minority carrier lifetime was associated with a decrease in interstitial oxygen related to D-defects in the Si crystal. (C) 2010 Elsevier B.V. All rights reserved.