Self-reorganization of CdTenanoparticles into two-dimensional Bi2Te3/CdTenanosheets and their thermoelectrical properties

Abstract

A partial cation exchange reaction between CdTe nanoparticles and Bi³⁺ ions gives rise to spontaneous formation of two-dimensional Bi₂Te₃/CdTe nanosheets. The average size and thickness of the nanosheets are around 200 and 6.9 nm, respectively. Both CdTe and Bi₂Te₃, which are there as the form of nanoparticles with average sizes of 3.4 nm, are found to be homogenously distributed in the nanosheets. The Bi₂Te₃/CdTe nanosheets are further integrated into a pellet by using spark plasma sintering for optimizing thermoelectric performance. Compared with the bulk n-type Bi₂Te₃, the pellets composed of Bi₂Te₃/CdTe nanosheets exhibit a considerably low thermal conductivity, 0.63 W m⁻¹ K⁻¹, and a slightly high Seebeck coefficient, −182.2 μV K⁻¹, at room temperature.