CdZnTe crystals were grown by vertical gradient freezing (VGF) method with a Cd reservoir for controlling the Cd pressure under conditions such that the crystals are in equilibrium with a Cd vapor corresponding to the minimum deviation from stoichiometry. The precipitate size became smaller by a post growth annealing method in the VGF furnace after the crystal growth without using wafer annealing. The size became less than 2 µm. Precipitate-free crystals were also grown by controlling the cooling method. In addition, the carrier concentration of p-type CdZnTe crystals was reduced using polycrystals grown in pBN boats. We have found that the carrier concentration of p-type ingots is dependent on Na and Li impurity concentrations.