Thermoelectric properties of CuIn1-x AxTe2 (A- Al, Sn, Sb and Bi)

• Main Author: Denish Kumar Ammamuthu
• Other Authors: Kedar Hippalgaonkar
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2021
• Subjects: Engineering::Materials
• Online Access: https://hdl.handle.net/10356/147760
• Institution: Nanyang Technological University

Thermoelectric properties of CuIn1-xAxTe2 compounds whereby A is (Group III = Al, Group IV = Sn and Group V = Sb and Bi) with (x=0, 0.05 and 0.1) have been studied. We have synthesized the compounds through solid-state reaction followed by spark plasma sintering. The electrical and thermal properties were studied using ZEM-3 and PPMS. We achieved the high power factor with Sb doping among the prepared samples. Though the power factor decreased with Al doping from group III (isovalent), the thermal conductivity dramatically reduced due to precipitate at grain boundaries and surface. The thermal conductivity decreased from to 5.6 W/mK to 2.8W/mK at 300K. CuIn1-xSnxTe2 displays a reduction in electrical conductivity due to charge compensation cause by Sn2+ and Sn4+ as it replaces the Indium. The reduction in electrical properties leads to a lower power factor compared to the pristine compound. Both CuIn1-xSbxTe2 and CuIn1-xBixTe2 displays an increase in carrier concentration by introducing acceptors. This lead to higher electrical conductivity and high power factor. CuIn0.95Sn0.05Te2 exhibits a power factor of 1.10 at 650 K, which is higher than the power factor stated in the latest research paper on CuIn1-xGaxTe2. Further optimization can increase the power factor and enhance the zT value.