[2] Various BiSb alloys also superconduct at low temperatures,[3] are semiconductors,[1] and are used in thermoelectric devices.

[1] Pure bismuth is a semimetal, containing a small band gap, which leads to it having a relatively high conductivity (7.7×105 S/m at 20 °C).

[2] The highest temperatures at which Bi0.4Sb0.6, as a thin film of thicknesses 150–1350 Å, superconducts (the critical temperature Tc) is approximately 2 K.[3] Single crystal Bi0.935Sb0.065 can superconduct at slightly higher temperatures, and at 4.2 K, its critical magnetic field Bc (the maximum magnetic field that the superconductor can expel) of 1.6 T at 4.2 K.[7] Electron mobility is one important parameter describing semiconductors because it describes the rate at which electrons can travel through the semiconductor.

Bismuth antimonides are used as the n-type legs in many thermoelectric devices below room temperature.

The thermoelectric efficiency, given by its figure of merit zT = ⁠σS2T/λ⁠, where S is the Seebeck coefficient, λ is the thermal conductivity, and σ is the electrical conductivity, describes the ratio of the energy provided by the thermoelectric to the heat absorbed by the device.