Enhanced Figure-of-Merit in Hierarchical Tubular Porous Cuprous Selenide

Abstract

A melting congruent superionic thermoelectric material, Cu₂Se, with isotropic tubular porous structure was successfully fabricated through a typical gas eutectic transformation process. Elongated pores scoping from nanometric to micrometric were found homogeneously dispersed in the Cu₂Se matrix with different orientations, inside which a corrugated surface was observed and characterized. The as-fabricated samples behave slight fluctuation on Seebeck coefficient and electrical conductivity, while conspicuously reduced thermal conductivity, achieving an enhanced thermoelectric figure-of-merit, zT up to 2.1 at 873 K. Unlike other traditional porous materials, this structured Cu₂Se also presented anomalous intensification on mechanical properties, leading to a promising marketing application.

Keywords: thermoelectric materials, Cu2Se, structure engineering