The thermoelectric properties of two thermoelectric materials (Ca3Co4O9+delta and Ca3−xPrxCo3.95Ga0.05O9+delta) were investigated in this paper. The power factor of one of the samples was improved by 52% relative to the others. The second material tested had a 50% improvement in the figure of merit over the first material. The study concluded that partial substition of the Pr3+ ions can improve the thermoelectric properties of these ...
Author(s): Ankam Bhaskar, C.-S. Jhang, Chia-Jyi Liu, Huey-Lin Hsieh, Jing-Yi Huang
This paper proposes conducting carbon aerogels, composed of graphene and multi-walled carbon nanotubes, as an option for a thermoelectric material. The researchers found that this combination of materials increased the electrical conductivity and the Seebeck coefficient due to bridging effects, and decreased the thermal conductivity through high porosity and a uniquely structured 3-D skeleton. Atomic force microscopy and X-ray diffraction were used to quantify the physical structure of the aerogels. ...
Author(s): Aiping Zhang, Jinghong Zhao, Jinrong Wu, Lijuan Zhao, Quan Li, Xijing Sun, Zhouyue Lei
A series of Bi(2-x)Sb(x)Te3 powders were prepared via hydrothermal methods by varying x (x=1.45, 1.50, 1.55, 1.56). These powders were then heavily characterized by XRD, EDS, ICP-AES, TEM, SEM and the TPS technique. A low thermal conductivity was desired, so as to give the highest thermoelectric figure of merit (ZT). It was determined that the highest figure of merit was obtained when x=1.55, which resulted in a value of 1.65 ...
Author(s): Chia-Jyi Liu, Hsin -Chang Lai, Liang-Ru Chen, Yen-Liang Liu
CaMnO3 has been proposed for use in thermoelectric materials, due to its favourable thermoelectric properties. In this article, the effect of doping using bismuth and silicon to replace calcium and manganese respectively has been studied. Important properties of the doped compounds measured include thermopower, thermal conductivity, and electrical resistance. Different amounts of dopant are used, and it was determined that the compound Ca0.98Bi0.02Mn0.98Si0.02O3 has the highest ...
Author(s): Ankam Bhaskar, Chia-Jyi Liu, Ching-Lin Chang, J. J. Yuan
Vertically-aligned silicon nanowires (SiNWs) are investigated for their use as thermoelectric materials. Using a silver-induced electroless-etching method, SiNWs of varying lengths are prepared, which are expected to have lower thermal conductivities as compared to bulk silicon. A thermal constants analyzer is used to perform the thermal analysis of the SiNWs, and thermal conductivity values are reduced by up to 43%. Theoretical models are then used to explain the quantitative results obtained ...
Author(s): Ci-Ling Pan, Peichen Yu, Rone-Hwa Chou, Ting-Gang Chen
