Enhancement of thermoelectric efficiency in vapor deposited Sb₂Te₃ and Sb_1.8In_0.2Te₃ crystals

Abstract

Pure and indium doped antimony telluride (Sb 2 Te 3 ) crystals find applications in high performance room temperature thermoelectric devices. Owing to the meagre physical properties exhibited on the cleavage faces of melt grown samples, an attempt was made to explore the thermoelectric parameters of p-type crystals grown by the physical vapor deposition (PVD) method. The crystal structure of the grown platelets (9 mm× 8 mm× 2 mm) was identified as rhombohedral by x-ray powder diffraction method. The energy dispersive analysis confirmed the elemental composition of the crystals. The electron microscopic and scanning probe image studies revealed that the crystals were grown by layer growth mechanism with low surface roughness. At room temperature (300 K), the values of Seebeck coefficient S ( c) and power factor were observed to be higher for Sb 1.8 In 0.2 Te 3 crystals (155 μVK −1 , 2.669 × 10 −3 W/mK 2 ) than those of pure ones. Upon doping, the thermal conductivity κ ( c) was decreased by 37.14% and thus thermoelectric efficiency was improved. The increased figure of merit, Z = 1.23 × 10 −3 K −1 for vapour grown Sb 1.8 In 0.2 Te 3 platelets indicates that it could be used as a potential thermoelectric candidate.

60Co Gamma Irradiation and Annealing Effects on Transport Properties of Antimony Telluride Platelets Grown by Physical Vapor Deposition

“…The raw materials were melted at 700°C in a furnace for about 48 h and slowly cooled to room temperature. The synthesized polycrystalline ingot obtained was powdered and kept for growth in a dual-zone furnace, as described by Thankamma and Kunjomana [16]. From the obtained crystals, samples labeled 1-4 were subjected to gamma irradiation by a source of 60 Co having a rate of 3.0 kGy h -1 and 5-7 were annealed at 375, 475 and 575 K for 1 h in a vacuum chamber at a pressure of 1.33 9 10 -3 Pa.…”

Enhanced Thermoelectric Performance of Lightly Pb-Doped Sb2Te3 Polycrystalline Alloys for Power Generation in Midtemperature Range

“…However, Sb 2 Te 3 has been typically shown to exhibit a high thermoelectric performance when codoped with two or more elements [15][16][17][18]. The maximum achievable zT value for singly doped Sb 2 Te 3 alloys is 0.7, which is significantly lower than that obtained via codoping [13,19].…”

A strategy to optimize the thermoelectric performance in a spark plasma sintering process

“…Doping effects on Sb 2 Te 3 have been intensively studied for theoretical and applicational purposes. Dopant candidates such as bismuth16, selenium17, titanium18, vanadium19, and indium2021 have been examined. Indium is a promising dopant because it not only effectively suppresses the formation of antisite defects but also widens the bandgap of Sb 2 Te 3 , which is helpful in reducing the detrimental bipolar conduction at high temperatures.…”