Compositionally homogeneous Sb-doped (5 x 10(18) and 1 x 10(19) cm(-3)) Sio73Geo 27 bulk crystals were grown by a vertical gradient solution growth method. The sandwich sample Si (seed)/Sb-doped Ge/ Si (feed) was set up inside a furnace under a mild temperature gradient 0.57 C/mm for homogeneous growth. The Si composition was analyzed by electron probe micro-analysis (EPMA). It revealed that the Si composition was homogeneous and the lengths of the Sb-doped (5 x 10(18) and 1 x 10(19) cm(-3)) Si0.73Ge0.27 bulk crystals were 18.3 and 15.1 mm, respectively. Grain distribution was investigated by electron backscattered diffraction spectrum (EBSD). The Seebeck coefficients (440 and 426 V/K) of Sb-doped (5 x 10(18) and 1 x 10(19) cm(-3)) Sio73Geo 27 were higher than the reported value (211 V/K) of P-doped (5 x 10(19) cm(-3)) Sio 8Geo 2 at room temperature. Thermal conductivity of Ga and Sb-doped SiGe was decreased with temperature due to scattering of phonon at the temperature range between 313 and 913 K. The maximum ZT values of Ga and Sb-doped SiGe were 0.34 and 0.44 at 820 K, respectively. The ZT values of Ga and Sb-doped SiGe were higher (0.07 and 0.13) than the reported value of Ga-doped Sio oiGeolo (0.05) and P-doped (5 x 10(19) cm(-3)) Sio oGeo 2 bulk crystals at room temperature. The improvement in ZT value was caused by a decrease of thermal conductivity which related to a composition of the alloy and doping concentration in the crystal. (C) 2016 Elsevier B.V. All rights reserved.