Thermoelectric improvement of the figure of merit of zinc phosphate glass composites by a likely tunnel percolation mechanism

Abstract

Zinc phosphate glasses (ZPG) have emerged as new energy materials due to their femtosecond response and chemical durability. The present investigation renders the methodology to enhance the thermoelectric properties of ZPG by adding external guest graphitic particles. Herein, transport parameters, Seebeck coefficient, and thermal and electrical conductivities of zinc phosphate glass composites were measured as a function of graphite concentration, followed by the calculation of the thermoelectric figure of merit (Z T). It is observed that the thermoelectric properties of the ZPG/graphite composites are superior to that of the pristine ZPG matrix and significantly depend on the volume concentration of graphite filler. ZPG/graphite composite exhibiting with 5 vol. % graphite content imparts the best thermoelectric performance with a power factor of PF ≈ 0.98 μ W m - 1 K - 2 and Z T ≈ 2.6 × 10 - 4.