We report the measurement of microstructure and transport properties in pure Bi91Sb9 and heavily doped with Sn (0.8at%, 1.2at%, 2.4at%) foils prepared by the high velocity crystallization ≈ 5·105 K/s. The foil thickness was 30-100 μm. It is shown that the rapidly solidified alloys (Bi91-Sb9)100-xSnx has a microcrystalline structure and contains the dispersed tin particles. Their average size increases with increasing concentration of tin in the alloys and does not exceed 0.3 μm. The rapidly solidified foils have a microcrystalline structure and texture (1012). It is shown that the electrophysical properties of the alloys (Bi91 -Sb9)100-xSnx (x = 0,8 - 2,0) are determined mainly by holes. The foils are characterized by a high positive Peltier coefficient value and can be used for manufacturing the thermoelectric devices, working at the temperatures below room temperature.