nanostructured thermoelectric material

This study describes a method by which to synthesize SiO2 -based graphene nanoballs (SGB) using atmospheric pressure chemical vapor deposition (APCVD) with copper vapor assistance. This method should solve the contamination, damage, and high costs associated with silica-based indirect graphene synthesis. The SGB was synthesized using APCVD, which was optimized using the Taguchi method. Multiple synthesis factors were optimized and investigated to find the ideal synthesis condition to grow SGB for thermoelectric (TE) applications...

Heat is an inexhaustible source of energy, and it can be exploited by thermoelectronics to produce electrical power or electrical responses. The search for a low-cost thermoelectric material that could achieve high efficiencies and can also be straightforwardly scalable has turned significant attention to the halide perovskite family. Here, we report the thermal voltage response of bismuth-based perovskite derivates and suggest a path to increase the electrical conductivity by applying chalcogenide doping. The films were produced by drop-casting or spin coating, and sulfur was introduced in the precursor solution using bismuth triethylxanthate...

Nanostructured semiconductors promise functional thermal management for microelectronics and thermoelectrics through a rich design capability. However, experimental studies on anisotropic in-plane thermal conduction remain limited, despite the demand for directional heat dissipation. Here, inspired by an oriental wave pattern, a periodic network of bent wires, we investigate anisotropic in-plane thermal conduction in nanoscale silicon phononic crystals with the thermally dead volume. We observed the anisotropy reversal of the material thermal conductivity from 1...

Thermoelectric materials can realize direct and mutual conversion between electricity and heat. However, developing a strategy to improve high thermoelectric performance is challenging because of strongly entangled electrical and thermal transport properties. We demonstrate a case in which both pseudo-nanostructures of vacancy clusters and dynamic charge-carrier regulation of trapped-hole release have been achieved in p-type lead telluride-based materials, enabling the simultaneous regulations of phonon and charge carrier transports...

Functional materials such as magnetic, thermoelectric, and battery materials have been revolutionized through nanostructure engineering. However, spin caloritronics, an advancing field based on spintronics and thermoelectrics with fundamental physics studies, has focused only on uniform materials without complex microstructures. Here, we show how nanostructure engineering enables transforming simple magnetic alloys into spin-caloritronic materials displaying significantly large transverse thermoelectric conversion properties...

Flexible thermoelectric generators (FTEGs), which can overcome the energy supply limitations of wearable devices, have received considerable attention. However, the use of toxic Te-based materials and fracture-prone electrodes constrains the application of FTEGs. In this study, a novel Ag2 Se and Poly (3,4-ethylene dioxythiophene): poly (styrene sulfonate) (PEDOT:PSS)/multi-walled carbon nanotube (MWCNT) FTEG with a high output performance and good flexibility is developed. The thermoelectric columns formulated in the work are environmentally friendly and reliable...

Thermoelectric technology has potential for converting waste heat into electricity. Although traditional thermoelectric materials exhibit extremely high thermoelectric performances, their scarcity and toxicity limit their applications. Zinc oxide (ZnO) emerges as a promising alternative owing to its high thermal stability and relatively high Seebeck coefficient, while also being earth-abundant and nontoxic. However, its high thermal conductivity (>40 W m-1 K-1 ) remains a challenge. In this study, we use a multi-step strategy to achieve a significantly high dimensionless figure-of-merit (zT) value of approximately 0...

Calcium titanium oxide has emerged as a highly promising material for optoelectronic devices, with recent studies suggesting its potential for favorable thermoelectric properties. However, current experimental observations indicate a low thermoelectric performance, with a significant gap between these observations and theoretical predictions. Therefore, this study employs a combined approach of experiments and simulations to thoroughly investigate the impact of structural and directional differences on the thermoelectric properties of two-dimensional (2D) and three-dimensional (3D) metal halide perovskites...

The creation of hierarchical nanostructures can effectively strengthen phonon scattering to reduce lattice thermal conductivity for improving thermoelectric properties in inorganic solids. Here, we use Zn doping to induce a remarkable reduction in the lattice thermal conductivity in SnTe, approaching the theoretical minimum limit. Microstructure analysis reveals that ZnTe nanoprecipitates can embed within SnTe grains beyond the solubility limit of Zn in the Zn alloyed SnTe. These nanoprecipitates result in a substantial decrease of the lattice thermal conductivity in SnTe, leading to an ultralow lattice thermal conductivity of 0...

A race to achieve a crossover from positive to negative magnetoresistance is intense in the field of nanostructured materials to reduce the size of memory devices. Here, the unusual complex magnetoresistance in nonmagnetic sulfur-doped Sb2 Se3  nanowires is demonstrated. Intentionally, sulfur is doped in such a way to nearly achieve the charge neutrality point that is evident from switching of carrier type from p-type to n-type at 13 K as inferred from the low-temperature thermoelectric power measurements...

Traditional thermoelectric materials often face a trade-off between efficient power generation (high ZT) and cooling performance. Here, we explore the potential of achieving simultaneous thermoelectric power generation and cooling capability in the recently fabricated bulk ZrSeTe Janus structure using first-principles density functional theory (DFT). The layered ZrSeTe Janus structure exhibits a semimetal character with anisotropic transport properties along the in-plane and out-of-plane directions. Our DFT calculations, including the explicit calculation of relaxation time, reveal a maximum ZT of ~0...

Flexible thermoelectric devices of nanomaterials have shown a great potential for applications in wearable to remotely located electronics with desired shapes and geometries. Continuous powering up the low power flexible electronics is a major challenge.  We are reporting a flexible thermoelectric module prepared from silver telluride (Ag2Te) nanowires (NWs), which are chemically transformed from uniquely synthesized and scalable tellurium (Te) NWs. Conducting Ag2Te NWs composites have shown an ultralow total thermal conductivity ~ 0...

This work presents the synthesis of novel copper oxide-multiwalled carbon nanotube (CuO-MWCNT) hybrid nanostructured composites and a systematic study of their thermoelectric performance at near-room temperatures as a function of MWCNT wt% in the composite. The CuO-MWCNT hybrid nanostructured composites were synthesized by thermal oxidation of a thin metallic Cu layer pre-deposited on the MWCNT network. This resulted in the complete incorporation of MWCNTs in the nanostructured CuO matrix. The thermoelectric properties of the fabricated CuO-MWCNT composites were compared with the properties of CuO-MWCNT networks prepared by mechanical mixing and with the properties of previously reported thermoelectric [CuO]99...

Enhancing the performance of thermoelectric materials is demanded to develop strategies for introducing multidimensional microstructures into materials to induce full-scale phonon scattering while ensuring electrical transport performance. Herein, a previously unreported rhombohedral h-SnTe ( R 3̄ m ) has been achieved in the nanoscale dimension by the electron beam irradiation of β-SnTe ( Fm 3̄ m ) materials. The h-SnTe structure contains interlayer van der Waals gaps and exhibits metallic behavior evaluated by density-functional theory calculations, which coherently appears in the narrow-band semiconductor β-SnTe matrix...

The development of green, renewable energy conversion and storage systems is an urgent task to address the energy crisis and environmental issues in the future. To achieve high performance, stable, and safe operation of energy conversion and storage systems, energy materials need to be modified and fabricated through rationalization. Among various modification and fabrication strategies, ion beam technology has been widely used to introduce various defects/dopants into energy materials and fabricate various nanostructures, where the structure, composition, and property of prefabricated materials can be further accurately tailored to achieve better performance...

Thermoelectric generators convert heat into a potential difference with arrays of p- and n-type materials, a process that allows thermal energy harvesting and temperature detection. Thermoelectric sensors have attracted interest in relation to the creation of temperature and combustible gas sensors due to their simple operation principle and self-powering ability. CuI is an efficient p-type thermoelectric material that can be readily produced from a Cu layer by an iodination method. However, the vapor iodination of Cu has the disadvantage of weak adhesion on a bare glass substrate due to stress caused by crystal growth, limiting microfabrication applications of this process...

Mg3 Bi2-v Sbv (0 ≤ v ≤ 2) is a class of promising thermoelectric materials that have a high thermoelectric performance around room temperatures, whereas their thermoelectric properties under pressures and temperatures are still illusive. In this study, we examined the influence of pressure, temperature, and carrier concentration on the thermoelectric properties of Mg3 Bi2-v Sbv using first-principle calculations accompanied with Boltzmann transport equations method. There is a decrease in the lattice thermal conductivity of Mg3 Sb2 (i...

In this contribution, a comprehensive study of nanostructured Bi2 Te3 (BT) thermoelectric material was performed using a combination of synchrotron radiation-based techniques such as XAFS, and XRF, along with some other laboratory techniques such as XRD, XPS, FESEM, and HRTEM. This study aims to track the change in morphological, compositional, average and local/electronic structures of Bi2 Te3 of two different phases; nanostructure (thin film) and nanopowders (NPs). Bi2 Te3 nanomaterial was fabricated as pellets using zone melting process in a one step process, while Bi2 Te3 thin film was deposited on sodalime glass substrate using a vacuum thermal evaporation technique...

Incorporating donor doping into Mg3 Sb1.5 Bi0.5 to achieve n-type conductivity is one of the crucial strategies for performance enhancement. In pursuit of higher thermoelectric performance, we herein report co-doping with Te and Y to optimize the thermoelectric properties of Mg3 Sb1.5 Bi0.5 , achieving a peak ZT exceeding 1.7 at 703 K in Y0.01 Mg3.19 Sb1.5 Bi0.47 Te0.03 . Guided by first-principles calculations for compositional design, we find that Te-doping shifts the Fermi level into the conduction band, resulting in n-type semiconductor behavior, while Y-doping further shifts the Fermi level into the conduction band and reduces the bandgap, leading to enhanced thermoelectric performance with a power factor as high as >20 μW cm-1 K-2 ...

Recently, there has been growing academic interest in researching thermoelectric materials that exhibit energy conversion capability between thermal energy and electricity, providing solutions to energy crises and environmental pollution [...].