Preparation and Thermoelectric Properties of Nanoporous Bi2Te3-Based Alloys

n-Type nanoporous Bi2Te3-based thermoelectric materials with different porosity ratios have been prepared by spark plasma sintering (SPS). The microstructure and phase morphology have been analyzed by x-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM), and the thermoelectric properties of the SPS samples have been measured. Experimental results show that the nanoporous structures lying in the sheet layers and among the plate grains of the Bi2Te3 bulk material can lead to an increase in the Seebeck coefficient and a decrease in the thermal conductivity, thus leading to an enhanced figure of merit.