- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Effect of indium and antimony doping on the transport properties of direct vapour transport (DVT) grown SnSe single crystals
摘要： Pure SnSe, 5% In, 10% In, 5% Sb, and 10% Sb doped SnSe single crystals were grown by the direct vapour transport technique. The energy dispersive X-ray analysis study of the samples showed them to be near stoichiometric but slightly Sn deficient. The X-ray diffraction study of all the as-grown single crystal samples showed that they possess an orthorhombic structure and the lattice parameters are in good agreement with the reported parameters. The thermoelectric power (S), dc electrical conductivity (σ), and thermal conductivity (κ) variation with temperature from ambient to 573 K substantiated the semiconducting nature of all the five samples. The sign of “S” was positive for all five samples for all the temperature range stating the sample to be a p-type semiconductor. The power factor (S2σ) and figure of merit (ZT) variation with temperature showed that pure SnSe possesses the highest value compared to doped samples. The obtained results are studied and discussed in detail.
关键词： direct vapour transport,thermoelectric,SnSe,doping,single crystals
更新于2025-09-09 09:28:46
-
Performance enhance of CMOS-MEMS thermoelectric infrared sensor by using sensing material and structure design
摘要： This study presents the micro thermoelectric infrared sensor consisted of the heat material. Experiment results indicate the Detectivity of proposed design is 2-2.6 fold higher The proposed infrared absorber design has an umbrella-like structure with a post anchor to the TSMC 0.18μm 1P6M standard CMOS process and the in-house post-CMOS MEMS process. (infrared sensor consisted of only the serpentine structure with embedded thermocouple), a transduction absorber and the serpentine structure with embedded thermocouple using the serpentine suspension with embedded thermocouple. As compare with the reference design much higher Seebeck coefficient (56-fold), and is employed in this study as the thermocouple junctions is increased. Moreover, the umbrella-like structure has higher infrared absorption area with and without Silicide are respectively characterized. The poly-Si with no Silicide has a as compare with the serpentine structure. In addition, the Seebeck coefficients of poly-Si films better heat-flow path is achieved and the temperature difference between the hot and cold than that of the reference one at 200mtorr. Experiment also show that the responsivity enhancement of proposed design is further increased as the sensor size is reduced in area.
关键词： thermoelectric,Seebeck effect,thermopile,CMOS-MEMS,infrared sensor
更新于2025-09-09 09:28:46
-
Flexible TEG Using Amorphous InGaZnO Thin Film
摘要： We have demonstrated ?exible thermoelectric generators (TEGs) using transverse type structure with amorphous InGaZnO/Mo and amorphous InGaZnO/ITO materials. The amorphous-InGaZnO (a-IGZO) ?lm has advantages such as its low thermal conductivity and relatively high carrier mobility. Additionally, the a-IGZO ?lm can form on a ?exible substrate using a low temperature fabrication process. The a-IGZO thin ?lms were deposited at room temperature by RF magnetron sputtering on PEN substrate. The thin ?lm TEG can create a temperature difference in the in-plane lateral direction by using a heat guide. For the heat guide, polymer photoresist material (KMPR 1035) was spin-coated and patterned using the standard photolithography process. Metal masks were used for all the deposition steps. A total of 676 a-IGZO/metal paired cells were connected in series. Temperature difference was applied between the heat guide and the back side of the substrate, and it was con?rmed that both temperature difference and Seebeck voltage were generated in the IGZO cell. We have shown that the transparent and ?exible TEG on PEN substrate can be fabricated using a-IGZO with the standard fabrication process.
关键词： thin ?lm,TAOS,Thermoelectric generator,module
更新于2025-09-04 15:30:14
-
Investigations on electrical and thermal transport properties of Cu2SnSe3 with unusual coexisting nanophases
摘要： The ternary diamond-like compound Cu2SnSe3 is a potential thermoelectric material. Its Cu-Se conducting network leaves Sn as a likely doping site to optimize the carrier concentration without much deterioration to the carrier mobility. Thus, the precise determination on the intricate phase structures of Cu2SnSe3 is critical. Here, we first use the atomically resolved scanning transmission electron microscopy and reveal an unusual phase coexistence (monoclinic and orthorhombic phases) in Ag-doped Cu2SnSe3. Owing to coexisting phases and the orderedisorder transition in the orthorhombic phase, the Ag-doped Cu2SnSe3 shows an unusual three-stage behavior in its temperature-dependent electrical transport properties and achieves record high power factors in this system. The observed three-stage behavior due to the phase coexistence is supported by the first principle calculations, Hall measurements, and optical diffuse reflectance measurements. To fully understand the band structures and the coherent interface between these coexisting phases, a band contact model is proposed that could well explain the three-stage electrical transport behavior. Moreover, the phase coexistence is observed at the nanoscale regime, thus providing a high density of phase boundaries. Such coexisting nanophases play an important role in lowering the lattice thermal conductivity. As a result, the ZT value obtained in Cu2Sn0.93Ag0.07Se3 is double that of undoped Cu2SnSe3.
关键词： Diamond-like compound,Phase coexistence,Thermoelectric,Cu2SnSe3
更新于2025-09-04 15:30:14
-
Formation mechanism of twin structures in p-type (Bi0.25Sb0.75)2Te3 thermoelectric compound
摘要： The formation mechanism of twin structures in p-type (Bi0.25Sb0.75)2Te3 compound was examined using high-resolution transmission electron microscopy (HR-TEM) and computer simulations. The results shown that the formation of twins is analogous to the twinning mechanism via synchronized activation of Shockley partial dislocations commonly observed terminating {111} growth and annealing twins in face centered cubic (FCC) metals. The f1010g boundary, as an incoherent twin boundary (ITB), is mobile due to its lower shear stress compared to that of the coherent {0001} twin boundary; thickness of the twin region can be reduced or increased according to the direction of the movement.
关键词： Twin structure,Interfacial step,Transmission electron microscopy (TEM),(Bi, Sb)2Te3 thermoelectric compound
更新于2025-09-04 15:30:14
-
Electron and phonon transport properties of layered Bi <sub/>2</sub> O <sub/>2</sub> Se and Bi <sub/>2</sub> O <sub/>2</sub> Te from first-principles calculations
摘要： Recent experiments indicated that both layered Bi2O2Se and Bi2O2Te are promising thermoelectric materials with low thermal conductivities. However, theoretical study on the thermoelectric properties, especially the phonon transport properties, is rare. In order to understand the thermoelectric transport mechanism, we here investigate the electron and phonon transport properties by using the first-principles calculations combined with the Boltzmann transport theory. Our results indicate that both Bi2O2Se and Bi2O2Te are semiconductors with indirect energy gaps of 0.87 eV and 0.21 eV within spin–orbit coupling, respectively. Large Seebeck coefficient and power factor are found in the p-type than the n-type for both compounds. Low lattice thermal conductivities at room temperature are obtained, 1.14 W m?1 K?1 for Bi2O2Se and 0.58 W m?1 K?1 for Bi2O2Te, which are close to the experimental values. It is found that the low-frequency optical phonon branches with higher group velocity and longer lifetime also make a main contribution to the lattice thermal conductivity. Interestingly, the lattice thermal conductivity exhibits obvious anisotropy especially for Bi2O2Te. These results are helpful for the understanding and optimization of thermoelectric performance of layered Bi2O2Se and Bi2O2Te.
关键词： thermoelectric,Bi2O2Se,lattice thermal conductivity,Bi2O2Te,first-principles
更新于2025-09-04 15:30:14
-
Polymer morphology and interfacial charge transfer dominate over energy-dependent scattering in organic-inorganic thermoelectrics
摘要： Hybrid (organic-inorganic) materials have emerged as a promising class of thermoelectric materials, achieving power factors (S2σ) exceeding those of either constituent. The mechanism of this enhancement is still under debate, and pinpointing the underlying physics has proven dif?cult. In this work, we combine transport measurements with theoretical simulations and ?rst principles calculations on a prototypical PEDOT:PSS-Te(Cux) nanowire hybrid material system to understand the effect of templating and charge redistribution on the thermoelectric performance. Further, we apply the recently developed Kang-Snyder charge transport model to show that scattering of holes in the hybrid system, de?ned by the energy-dependent scattering parameter, remains the same as in the host polymer matrix; performance is instead dictated by polymer morphology manifested in an energy-independent transport coef?cient. We build upon this language to explain thermoelectric behavior in a variety of PEDOT and P3HT based hybrids acting as a guide for future work in multiphase materials.
关键词： polymer morphology,charge transport,PEDOT:PSS,thermoelectric materials,hybrid materials
更新于2025-09-04 15:30:14
-
Bipolar Thermoelectric Effects in Semiconducting Carbon Nanotubes: Description in Terms of One-Dimensional Dirac Electrons
摘要： The thermoelectric effects in semiconducting single-walled carbon nanotubes (SWCNTs) are investigated based on the linear response theory combined with the thermal Green’s function method. It is shown that the electronic states near the lowest conduction band minimum and the highest valence band maximum can be effectively described in terms of one-dimensional (1D) Dirac electrons to which a theoretical scheme is developed to describe the thermoelectric responses making it possible to study the effects of inter-band impurity scattering and in-gap states. Using the proposed scheme, the bipolar thermoelectric effects (i.e., the sign inversion of the Seebeck coefficient) in semiconducting SWCNTs observed in recent experiments are explained. Moreover, the temperature dependence of the Seebeck coefficient of semiconducting SWCNTs at low temperature is clarified.
关键词： thermal Green’s function method,Seebeck coefficient,linear response theory,Dirac electrons,semiconducting single-walled carbon nanotubes,thermoelectric effects
更新于2025-09-04 15:30:14
-
Multiphysics THz Antenna Simulations
摘要： The electrical response of an antenna-coupled nanothermocouple depends on how well the antenna converts incident optical energy to heat, and how this heat is converted to electrical signals by the nanothermocouples. In this paper, we study by COMSOL simulations the heat dissipated in dipole antennas operating at 600 GHz to maximize the temperature at the center of the antenna where the nanothermocouples are attached. We study antennas constructed from all-Au, all-Ni, and Au with Ni center segment. We also study the heat loss into the Si substrate, and use various thicknesses of SiO2 for thermal insulation from the substrate. We also discuss our simulation setup and our symmetric, geometry-independent mesh structure to avoid a variety of simulation errors and artifacts.
关键词： Simulation,Nanotechnology,Thermoelectricity,Thermoelectric devices,Antennas
更新于2025-09-04 15:30:14
-
[SpringerBriefs in Materials] Anisotropic Metal Chalcogenide Nanomaterials (Synthesis, Assembly, and Applications) || Applications
摘要： Interest in anisotropic 1D and 2D nanostructures has been steadily increasing due to their large surface area, quantum con?nement effect, and superior optoelectrical or thermoelectrical properties. Anisotropic geometry and size reduction comparable to the Debye length can alter the optical, electric, and magnetic properties of the bulk counterparts. Focusing on MCs prepared in solution the major interests for practical applications are thermoelectric power phases, generation or electronic device cooling, high performance electrodes for batteries, nanocrystal-based photovoltaic devices, and photodetectors. Recently, new potential uses of the solution-based MC nanocrystals are being investigated, which include localized surface plasmon resonance (LSPR) and oxygen reduction reaction (ORR). MC thin ?lms prepared by the vacuum process have shown the possibilities as new class of materials such as topological insulator, semiconductor with a high electron mobility, and superconductor. Although the organic surfactants indispensable in solution chemistry diminish such superior physical properties, solution-based approach has large room to achieve such physical properties. This chapter will introduce recent advances in the practical applications of the anisotropic MC nanocrystals, and introduce brie?y the potential applications.
关键词： thermoelectric,oxygen reduction reaction,photodetector,metal chalcogenides,localized surface plasmon resonance,photovoltaic,superconductor,topological insulator,anisotropic nanostructures
更新于2025-09-04 15:30:14