Thermoelectric properties of electron- and hole-doped BaFe2As2

We investigate the resistivity and thermoelectric power properties for Co- or K-doped BaFe2As2 systems. T-c as a function of Co- or K-doping level exhibits a domelike behavior in both of the systems. The thermoelectric power (S) at room temperature as a function of doping level (x) shows a domelike behavior in Ba1-xKxFe2As2 system while monotonously decreases in BaFe2-xCoxAs2 system. It is intriguing that the superconducting samples simultaneously show large absolute values of thermoelectric power and good conductivity. The power factor shows a peak at low temperature, suggesting possible applications in thermoelectric cooling modules around the liquid-nitrogen temperature range.