PbTe has proven to be a very important intermediate
thermoelectric material. The performance of thermoelectric materials can be evaluated by the figure of merit, ZT=S^2\sigma T/\kappa, in which S is the
Seebeck coefficient, \sigma is the
electrical conductivity and \kappa is the
thermal conductivity. In order to improve the thermoelectric performance of materials, the power factor (S^2\sigma) needs to be maximized and the thermal conductivity needs to be minimized. With this approach, point defects, nanoscale precipitates and mesoscale grain boundaries are introduced as effective scattering centers for
phonons with different mean free paths, without affecting charge carrier transport. By applying this method, the record value for zT of PbTe that has been achieved in Na doped PbTe-SrTe system is approximately 2.2. In addition, PbTe is also often alloyed with tin to make
lead tin telluride, which is used as an
infrared detector material. == See also ==