Thermoelectric Characteristics of Heavily Doped p-Type Lead Telluride at Different Heavy-Hole Band Depths

• Published in: Semiconductors (Woodbury, N.Y.) Vol. 53; no. 4; pp. 419 - 427
• Main Author: Dmitriev, A. V.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.04.2019; Springer; Springer Nature B.V
• Subjects: Doping; Electronic Properties of Semiconductors; Intermetallic compounds; Lead tellurides; Magnetic Materials; Magnetism; Mathematical analysis; Physics; Physics and Astronomy; Thermoelectricity
• ISSN: 1063-7826; 1090-6479
• DOI: 10.1134/S1063782619040079

The full set of thermoelectric parameters of heavily doped p -PbTe in the temperature range of 300–1200 K at an acceptor doping level of N a = 1 × 10 19 –4 × 10 20 cm –3 and a heavy-hole band depth ranging from 0.36 to 0.7 eV is calculated. The figure-of-merit value Z is found to be highly sensitive to the doping level and increased by a factor of 1.5 with an increase in the dopant concentration from 1 × 10 19 to 5 × 10 19 cm –3 ; the maximum Z value is found to correspond to N a = (1–2) × 10 20 cm –3 . It is demonstrated that the change in the heavy-hole band depth leads to a noticeable shift of the Z maximum position along the temperature axis without noticeable Z maximum variation. The temperature corresponding to the maximum Z value is similar to that at which the top of the light-hole band crosses the Fermi level. The maximum calculateded ZT value is shown to be 1.64. At a heavy-hole band depth of 0.5 eV, the calculated results agree well with the available experimental data.