The Thermoelectric Properties of -Type Bismuth Telluride: Bismuth Selenide Alloys BiTe Se .

Alloying bismuth telluride with antimony telluride and bismuth selenide for - and -type materials, respectively, improves the thermoelectric quality factor for use in room temperature modules. As the electronic and thermal transports can vary substantially, the alloy composition is a key engineering parameter. The -type BiTe Se alloy lags its -type counterpart in thermoelectric performance and does not lend itself as readily to simple transport modeling which complicates engineering.

Self-Tuning n-Type Bi(Te,Se)/SiC Thermoelectric Nanocomposites to Realize High Performances up to 300 °C.

BiTe 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 of ≈0.85 at 200 to 300 °C can be achieved by doping small amounts of copper iodide (CuI) in BiTeSe-silicon carbide (SiC) composites, where SiC nanodispersion enhances the flexural strength.

Nanocomposites from Solution-Synthesized PbTe-BiSbTe Nanoheterostructure with Unity Figure of Merit at Low-Medium Temperatures (500-600 K).

A scalable, low-temperature solution process is used to synthesize precursor material for Pb-doped Bi Sb Te thermoelectric nanocomposites. The controllable Pb-doping leads to the increase in the optical bandgap, thus delaying the onset of bipolar conduction. Furthermore, the solution synthesis enables nanostructuring, which greatly reduces thermal conductivity.

Hybridization Gap in the Semiconducting Compound SrIrInGe.

Large single crystals of SrIrInGe were synthesized using the In flux method. This compound is a hybridization gap semiconductor with an experimental optical band gap of E = 0.25(3) eV.

n-Type Bi2Te3-xSex Nanoplates with Enhanced Thermoelectric Efficiency Driven by Wide-Frequency Phonon Scatterings and Synergistic Carrier Scatterings.

Driven by the prospective applications of thermoelectric materials, massive efforts have been dedicated to enhancing the conversion efficiency. The latter is governed by the figure of merit (ZT), which is proportional to the power factor (S(2)σ) and inversely proportional to the thermal conductivity (κ). Here, we demonstrate the synthesis of high-quality ternary Bi2Te3-xSex nanoplates using a microwave-assisted surfactant-free solvothermal method.

Hybridization Gap and Dresselhaus Spin Splitting in EuIr4In2Ge4.

EuIr4In2Ge4 is a new intermetallic semiconductor that adopts a non-centrosymmetric structure in the tetragonal I4̄2m space group with unit cell parameters a=6.9016(5) Å and c=8.7153(9) Å.

Contrasting role of antimony and bismuth dopants on the thermoelectric performance of lead selenide.

Increasing the conversion efficiency of thermoelectric materials is a key scientific driver behind a worldwide effort to enable heat to electricity power generation at competitive cost. Here we report an increased performance for antimony-doped lead selenide with a thermoelectric figure of merit of ~1.5 at 800 K.

High ZT in p-type (PbTe)1-2x(PbSe)x(PbS)x thermoelectric materials.

Lead chalcogenide thermoelectric systems have been shown to reach record high figure of merit values via modification of the band structure to increase the power factor or via nanostructuring to reduce the thermal conductivity. Recently, (PbTe)1-x(PbSe)x was reported to reach high power factors via a delayed onset of interband crossing. Conversely, the (PbTe)1-x(PbS)x was reported to achieve low thermal conductivities arising from extensive nanostructuring.

NMR probe of metallic states in nanoscale topological insulators.

A 125Te NMR study of bismuth telluride nanoparticles as a function of particle size revealed that the spin-lattice relaxation is enhanced below 33 nm, accompanied by a transition of NMR spectra from the single to the bimodal regime. The satellite peak features a negative Knight shift and higher relaxivity, consistent with core polarization from p-band carriers. Whereas nanocrystals follow a Korringa law in the range 140-420 K, micrometer particles do so only below 200 K.