Enhancement of the thermoelectric properties in β-Cu2+xSe/a-C nano-multilayer films by heterogeneous interfaces

The beta-Cu2+xSe/a-C nano-multilayer films were prepared. The carrier concentration, mobility and thermal conductivity decrease and the resistivity and Seebeck coefficient increase with reducing the modulation periods. For the beta-Cu2+xSe/a-C nano-multilayer film with the lowest modulation period 160 nm, the power factor and ZT value reach 0.57 mWmiddotm-1middotK-2 and 0.42 at room temperature, respectively. Enhanced power factor and ZT values in the nano-multilayer films are attributed to scattering effect of the depletion layer at the beta-Cu2+xSe/a-C interface that decreases the carrier concentration and mobility. The existence of the heterogeneous interface effectively increases the Seebeck coefficient and decreases thermal conductivity due to increasing the scattering effect of carriers and phonons. The introduction of a-C layer with high electric conduction into beta-Cu2+xSe to form beta-Cu2+xSe/a-C nano-multilayer film can effectively improve its thermoelectric properties.(c) 2022 Elsevier B.V. All rights reserved.

Automated summary

The β-Cu2+xSe/a-C nano-multilayer films were prepared, and their thermoelectric properties were investigated. The modulation periods were found to affect the carrier concentration, mobility, thermal conductivity, resistivity, and Seebeck coefficient. The nano-multilayer films exhibited enhanced power factor and ZT values, which were attributed to the scattering effect of the depletion layer at the β-Cu2+xSe/a-C interface and the presence of the heterogeneous interface.