High Thermoelectric Performance of Co-Doped P-Type Polycrystalline SnSe via Optimizing Electrical Transport Properties.
ACS APPLIED MATERIALS & INTERFACES 2020;
12:8446-8455. [PMID:
31986003 DOI:
10.1021/acsami.9b20610]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
This work systematically investigated the thermoelectric properties of p-type Na and M (M = K, Li, Ag) codoped polycrystalline SnSe. It is found that the electrical properties of polycrystalline SnSe can be improved significantly for (Na, Ag) codoped samples, contributed by the enhanced carrier concentration. Specifically, a carrier concentration of 6.23 × 1019 cm-3 was obtained in Sn0.98Na0.016Ag0.004Se sample at 335 K, an increase of 18% compared with that of the Na single-doped sample (5.22 × 1019 cm-3). The power factor reached ∼0.73 mW m-1 K-2 for the Sn0.98Na0.016Ag0.004Se sample at 785 K, enhanced by ∼26% compared with Na single-doped one. In addition, Sn-rich and Ag-rich particles/areas observed in the matrix of Sn0.98Na0.016Ag0.004Se contribute to the reduction of lattice thermal conductivity from 0.61 W m-1 K-1 for Sn0.98Ag0.02Se to 0.47 W m-1 K-1 at 785 K. The combination of simultaneously enhanced power factor and depressed thermal conductivity leads to a maximum ZT ≈ 1.2 at 785 K and a high average ZT ≈ 0.74 at 335-785 K for Sn0.98Na0.016Ag0.004Se, and generating a high theoretical conversion efficiency of ∼11%. These illuminating discoveries could provide routes to enhance the thermoelectric performance in p-type polycrystalline SnSe.
Collapse