Exploring the impact of doping and processing strategies on the thermoelectric performance of 1D/2D tellurium nanocomposites

Abstract

With increasing demand for heat-electricity energy conversion in various fields increases, materials engineering to improve the performance of thermoelectric materials has gained momentum. Here, we synthesized film-type nanocomposites (NCs) comprising one-dimensional tellurium nanowires and two-dimensional tellurium nanosheets and investigated the effects of dopants on the morphological and thermoelectric characteristics. After the NCs were subjected to either vacuum drying (NCs (V)) or freeze-drying (NCs (F)), the samples were doped with silver, copper, and indium, respectively. The characterization results indicated that Ag and Cu doping led to significant structural changes, whereas In doping had a minimal effect on the structure. The thermoelectric performance, evaluated in terms of power factor (PF), varied with the type of dopant and drying method. The highest PF values were observed in Cu-doped NCs, with Cu@NCs (V) and Cu@NCs (F) exhibiting values of 53.04 and 47.58 μW/mK², respectively, primarily due to a substantial increase in electrical conductivity. The Ag-doped NCs also exhibited improved PF values, whereas the In-doped NCs exhibited only a modest improvement in PF. These results demonstrate that the precise selection of the TE matrix, dopants, and processing conditions can effectively optimize both the conductivity and Seebeck coefficient, leading to high PF values in TE materials.

Graphical abstract

The research demonstrates how controlled doping and varying drying conditions can significantly influence the electrical conductivity and Seebeck coefficient of the novel 1D/2D tellurium nanocrystal composites, leading to notable improvements in thermoelectric efficiency. The manuscript addresses key topics in sustainable energy materials science, such as nanomaterial compound engineering, thermoelectric performance optimization, and materials processing techniques.