Highly oriented [1 1 0] Bi2Te3 films were obtained by pulsed electrodeposition. The structure, composition, and morphology of these films were characterized. The thermoelectric figure of merit (zT), both parallel and perpendicular to the substrate surface, were determined by measuring the Seebeck coefficient, electrical conductivity, and thermal conductivity in each direction. At 300 K, the in-...

A thermoelectric thin-film device consisting of n-type Bi2Te3 and p-type Sb2Te3 thin-film legs was prepared on a glass substrate by using co-evaporation and annealing process. The Seebeck coefficient and the power factor of the co-evaporated Bi2Te3 film were 130μV/K and 0.7 © 1014W/K2·m, respectively, and became substantially improved to 1160μV/K and 16 © 1014W/K2·m by annealing at 400°C for 20...

The lattice dynamics in an array of 56 nm diameter Bi2Te3 nanowires embedded in a self-ordered amorphous alumina membrane were investigated microscopically using (125)Te nuclear inelastic scattering. The element specific density of phonon states is measured on nanowires in two perpendicular orientations and the speed of sound is extracted. Combined high energy synchrotron radiation diffraction ...

In thermoelectric devices, Bi2Te3 must be able to operate under high temperature gradients for very long times (years) without appreciable deformation, while being subjected to stresses created by internal thermal mismatch and external forces (e.g., vibrations). The deformation rate of cast, coarsegrained Bi2Te3 was measured under uniaxial compressive stresses from 2 to 16 MPa at temperatures b...

Over the past two decades several nano-structuring methods have helped improve the figure of merit (ZT) in the state-of-the art bulk thermoelectric materials. While these methods could enhance the thermoelectric performance of p-type Bi2Te3, it was frustrating to researchers that they proved ineffective for n-type Bi2Te3 due to the inevitable deterioration of its thermoelectric properties in th...

Bismuth telluride/iron telluride (Bi2Te3/Fe1+yTe) heterostructures are known to exhibit interfacial superconductivity between two non-superconducting materials: Fe1+yTe as the parent compound of Fe-based superconducting materials and topological insulator Bi2Te3. Here, a top-down approach is presented starting from 2D fabricate 1D Bi2Te3/Fe1+yTe nanowires or narrow nanoribbons. It demonstrated ...

The electronic structure of p-type doped Bi2Te3 is studied by angle resolved photoemission spectroscopy (ARPES) to experimentally confirm the mechanism responsible for the high thermoelectric figure of merit. Our ARPES study shows that the band edges are located off the Γ-Z line in the Brillouin zone, which provides direct observation that the spin-orbit interaction is a key factor to understan...

Anomalous Hall effect (AHE) was recently discovered in magnetic element-doped topological insulators (TIs), which promises low power consumption and high efficiency spintronics and electronics. This discovery broadens the family of Hall sensors. In this paper, AHE sensors based on Cr-doped Bi2Te3 topological insulator thin films are studied with two thicknesses (15 and 65 nm). It is found, in b...

The successful exfoliation of atomically-thin bismuth telluride (Bi2Te3) quintuple layer (QL) attracts tremendous research interest in this strongly anharmonic quasi-two-dimensional material. The thermal transport properties of this material are not well understood, especially the mode-wise properties and when it is coupled with a substrate. In this work, we have performed molecular dynamics si...

Thermoelectric figure-of-merits (ZT) are enhanced or degraded by crystal defects such as twins and excess atoms that are correlated with thermal conductivity (k) and carrier concentration (n). For Bi2Te3, it is unclear whether the crystal defects can enhance ZT without a degradation in the thermopower factor. In the present study, n-type Bi2Te3 nanowires (NWs) are electrochemically synthesized ...