Toward controlled thermoelectric properties of Pb and Sb co-doped nanostructured Thallium Telluride for energy applications

• Published in: Materials research express Vol. 7; no. 10; pp. 105010 - 105022
• Main Authors: Khan, Waqas Muhammad, Rahman, Altaf Ur, Tufail, Muhammad, Ibrar, Muhammad, Shah, Wiqar Hussain, Syed, Waqar Adil, Gul, Banat
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.10.2020
• Subjects: Antimony; Density functional theory; DFT; Electrical resistivity; electronic properties; GGA; Lead; Mathematical analysis; Nanoparticles; Nanostructure; Power factor; quaternary compound; Seebeck effect; Tellurides; Temperature dependence; Thallium; Thermal conductivity; thermoelectric properties; Transport properties
• ISSN: 2053-1591; 2053-1591
• DOI: 10.1088/2053-1591/abbb54

Abstract Here, the structure-dependent electronic, thermal, and transport properties of nanostructured thallium telluride (Tl 8 Pb x Sb 2− x Te 6 ) through controlled variation in Pb and Sb (x = 1.96, 1.97, 1.98, 1.99) concentrations have been investigated. In the temperature and concentration-dependent electrical conductivity measurements, the highest electrical conductivity 131.96 × 10 3 Ω − 1 m − 1 at 300 K was measured for x = 1.99 and the maximum observed Seebeck value for the optimized Tl 8 Pb 1.96 Sb 0.04 Te 6 nanoparticles was 110.7 μ V/K at 550 K. Such an increased value of the Seebeck coefficient led to the achievement of a significantly improved high-power factor, which was found to be increasing with temperature and decreasing with the increase of Pb concentration. The density functional theory calculations performed for Pb and Sb co-doped Tl 5 Te 3 resulted in the enhanced σ e and S with a significant reduction in electronic thermal conductivity ( κ e ) and is found consistent with experimentally measured κ e . The highest ZT = 0.35 and 0.18 were recorded experimentally and theoretically for Pb and Sb co-doped in Tl 5 Te 3 nanoparticles.