The embedding of nanoprecipitates into a semiconducting matrix can lead to improved thermoelectric performances by enhancing the power factor or reducing the thermal conductivity of the system in which they are incorporated. Thus, we herein demonstrate the successive annealing of an electrodeposited amorphous Ag-Sb-Te film for the simple and effective fabrication of a nanocomposite consisting of highly dense (∼6 vol%) β-Ag2Te nanoprecipitates in an Ag-doped Sb2Te3 matrix. During the annealing process, nanoscale (∼40 nm) β-Ag2Te precipitates were generated spontaneously due to differences in the binding energies of the Ag-Te and Sb-Te bonds. As a result, the electron-transport properties of the p-type Sb2Te3 were significantly enhanced in the presence of the β-Ag2Te nanoprecipitates owing to an energy-dependent carrier-filtering effect at the Ag-doped Sb2Te3/β-Ag2Te interface. Furthermore, a high power factor of 1870 μW m-1 K-2 was obtained at 300 K due to the increased density of states effective mass (m∗ ∼1.8m0) without any significant deterioration in the electrical conductivity being observed.
Bibliographical noteFunding Information:
This work was supported mainly by the Global Frontier Program through the Global Frontier Hybrid Interface Materials (GFHIM) project (grant number 2013M3A6B1078870) and Future Materials Discovery Program (grant number 2016M3D1A1027836) of the National Research Foundation of Korea (NRF), which is funded by the Ministry of Science, ICT, & Future Planning, and by the New & Renewable Energy Technology Development Program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) (grant number 20153030013200). This work was also supported by Korea Institute of Materials Science.
© 2018 The Royal Society of Chemistry.
All Science Journal Classification (ASJC) codes
- Renewable Energy, Sustainability and the Environment
- Materials Science(all)