Thermoelectric materials constitute an alternative source of sustainable energy, harvested from waste heat. Bi2Te3 is the most utilized thermoelectric alloy. We show that it can be readily prepared in nanostructured form by arc-melting synthesis, yielding mechanically robust pellets of highly oriented polycrystals. This material has been characterized by neutron powder diffraction (NPD), scanni...

This work presents a novel process to fabricate nanostructures for thermoelectric applications by a combination of a traditional silicon microfabrication techniques, electroplating, and submicron ion-track nanolithography. Polyimide (Kapton HN, PI2731), and PMMA (polymethyl methacrylate) were ion-track irradiated and wet etched. Bi2Te3 nanowires (80 and 120 nm diameter) were electroplated with ...

We have studied the polarization dependence of coherent phonons in the topological insulator Bi2Te3. Using polarization-dependent femtosecond pump-probe spectroscopy, we measured coherent phonons as a function of angle when the pump and probe polarizations were fixed, and the crystal orientation was rotated. For isotropic detection, depending on the spot position, oscillations either from only ...

Physical vapour deposition (PVD) is used to grow millimetre-long Bi2Te3 sub-micron belts catalysed by TiO2 nanoparticles. The catalytic efficiency of TiO2 nanoparticles for the nanostructure growth is compared with the catalyst-free growth employing scanning electron microscopy. The catalyst-coated and catalyst-free substrates are arranged side-by-side, and overgrown at the same time, to assure...

Bi2Te3 thermoelectric materials are utilized for refrigeration for decades, while their application of energy harvesting requires stable thermoelectric and mechanical performances at elevated temperatures. This work reveals that a steady zT of ≈0.85 at 200 to 300 °C can be achieved by doping small amounts of copper iodide (CuI) in Bi2Te2.2Se0.8-silicon carbide (SiC) composites, where SiC nanodi...

Three dimensional Z2 Topological insulator (TI) is an unconventional phase of quantum matter possessing insulating bulk state as well as time-reversal symmetry-protected Dirac-like surface state, which is demonstrated by extensive experiments based on surface sensitive detection techniques. This intriguing gapless surface state is theoretically predicted to exhibit many exotic phenomena when in...

The addition of Cu to layered Bi2Te3-based thermoelectric alloys has been studied as an effective way enhance transport properties. In this study, the influence adding Bi2Se3 alloys, which have same rhombohedral crystal structure Bi2Te3, was investigated by synthesizing a series CuxBi2Se3 (<i>x</i> = 0, 0.004, 0.008, 0.012, and 0.016) alloys. power factors all Cu-added samples were ...