Dramatic enhancement of thermoelectric power factor in PbTe:Cr co-doped with iodine

Abstract

We report thermoelectric properties of PbTe doubly doped with chromium (Cr) and iodine (I). Cr is found to create a local enhancement of density of states (DOS) in the conduction band of PbTe, and I is found to tune the position of the Fermi level. The coincidence of the Fermi level with the enhanced DOS is found to produce up to 135% enhancement in thermopower leading to a high power factor (PF) of 56.16 × 10−4 Wm−1K−2 at 500 K. Such high value of power factor can produce thermoelectric figure of merit (ZT) above 2.