Thermoelectric transport properties of BaBiTe₃-based materials

BaBiTe₃, a material with low thermal conductivity, is an inferior thermoelectric material due to the poor electrical properties originated from its narrow band gap. We choose two types of dopants, K and La, trying to optimize its electrical transport properties. The minority carriers, which harm the Seebeck coefficient in this system, are suppressed by La doping. With the increase of both electrical conductivity and Seebeck coefficient, the power factor of 3% La doped BaBiTe₃ reaches 3.7 μW cm⁻¹ K⁻² which increased by 40% from undoped BaBiTe₃. Besides high power factor, the thermal conductivity is also reduced in it. Eventually, a high ZT value, 0.25 at 473 K, for n-type BaBiTe₃ is achieved in 3% La doped BaBiTe₃.