Improved thermoelectric devices using bismuth alloys

We present first-principles transport calculations for bismuth utilizing the linearized-augmented plane-wave method. From the calculated transport distribution, we compute transport coefficients and our results agree well with experiment. Furthermore, we derive the power factor and find two pronounced maxima excelling even the power factor of Bi2Te3. These maxima can be related to the points of steepest slope in the transport distribution. This insight provides a very valuable guideline for the search of improved thermoelectric materials. The maximum in the power factor leads to a thermoelectric figure of merit of 1.44, which is considerably larger than the one for Bi2Te3. (C) 2004 American Institute of Physics.