Thermoelectric Properties of the Homologous Compounds Pb5Bi6Se14−xIx (x = 0.0, 0.025, and 0.05)
Homologous compounds represent an interesting platform for design of new thermoelectric materials. We report herein on synthesis, structural and chemical characterizations, and high-temperature (300 K to 700 K) transport properties measurements of Pb5Bi6Se14−xIx (x = 0.0, 0.025, and 0.05) homologous compounds. Successful insertion of iodine into the crystal structure of Pb5Bi6Se14 was confirmed by its influence on the transport properties. The doping effectiveness of iodine was demonstrated by the increase in the electron concentration, resulting in more pronounced metallic character of transport with respect to undoped Pb5Bi6Se14. The peak ZT value of 0.5, which was achieved at 700 K in the x = 0.025 sample, remains similar to that obtained in Pb5Bi6Se14.