We demonstrate the electrical and thermal transport properties of polycrystalline CoPn2 (Pn = As and Sb) between 300 and 900 K. CoAs2 shows semiconducting electrical transport up to 900 K, while CoSb2 exhibits degenerate conduction. Sign inversion of the Seebeck coefficient is observed at ∼310 and ∼400 K for CoAs2 and CoSb2, respectively. Thermal conductivity at 300 K is 11.7 Wm-1K-1 for CoAs2 and 9.4 Wm-1K-1 for CoSb2. The thermoelectric power factor of CoAs2 is ∼10 μWcm-1K-2, although the dimensionless figure of merit is limited to ∼0.1 due to relatively high thermal conductivity. Using electronic structure calculations, the band gap value is calculated to be 0.55 eV for CoAs2 and 0.26 eV for CoSb2.
ASJC Scopus subject areas
- Physics and Astronomy(all)