Thermoelectric Properties of p and n-type Nanocrystalline Silicon Nanowires with High Doping Levels

2012 ◽  
Vol 1408 ◽  
Author(s):  
F. Suriano ◽  
M. Ferri ◽  
S. Solmi ◽  
L. Belsito ◽  
A. Roncaglia ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Cross Section ◽  
Thermoelectric Properties ◽  
Silicon Nanowires ◽  
Low Cost ◽  
Nanocrystalline Silicon ◽  
Nanowire Diameter ◽  
Vertical Arrays ◽  
Heavily Doped ◽  
Average Size

ABSTRACTAn experimental investigation about the thermoelectric properties of heavily doped p ad n-type nanocrystalline silicon nanowires (NWs) is described. The NWs are produced with low cost CMOS compatible processes, highly customizable in terms of cross-section and placement, which enables the fabrication of both stacked NWs in nearly vertical arrays within nanostructured templates built with SiO2/Si3N4 thin films and individual, freestanding NWs suited for thermal conductivity measurements. The cross-section dimensions of the investigated NWs range between 30 and 120 nm in size and up to about 2 cm in length. The structure of the NWs, as shown by SEM/TEM observations, is nanocrystalline with average size of the nanocrystals in one dimension that is comparable with the nanowire diameter. On the NWs, Seebeck coefficient, electrical resistivity and thermal conductivity have been measured, yielding thermoelectric figure of merit (ZT) values of 0.2 at 300 K for the best case.

Simultaneous enhancements in the Seebeck coefficient and conductivity of PEDOT:PSS by blending ferroelectric BaTiO3 nanoparticles

2021 ◽  
Author(s):  
Chang'an Li ◽  
Xin Guan ◽  
Shizhong Yue ◽  
Xi Zu Wang ◽  
Jianmin Li ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Low Cost ◽  
Low Thermal Conductivity ◽  
Low Toxicity ◽  
Batio3 Nanoparticles

Thermoelectric polymers have attracted great attention because of their unique merits including low thermal conductivity, low cost, non- or low toxicity and high mechanical flexibility. However, their thermoelectric properties particularly...

The Effect of Cross-sectional Geometry on ZT Enhancement in Rough Silicon Nanostructures

2010 ◽  
Vol 1267 ◽  
Author(s):  
Jyothi Swaroop Sadhu ◽  
Marc G Ghossoub ◽  
Sanjiv Sinha
Keyword(s):  
Thermal Conductivity ◽  
Boundary Condition ◽  
Cross Section ◽  
Silicon Nanowires ◽  
Silicon Nanostructures ◽  
Dramatic Reduction ◽  
Cross Sectional ◽  
The Wire ◽  
Phonon Localization ◽  
The Impact

AbstractThe dramatic reduction in the thermal conductivity of rough silicon nanowires is due to phonon localization in the wire resulting from multiple scattering of phonons from the rough walls. We report the dependence of thermal conductivity of the nanowires as a function of the surface roughness and the diameter of the wire by modeling the nanowire as a waveguide. In addition, we estimate the impact of boundary condition, dimensionality and cross section of rough wire on the thermal conductivity. This theoretical model gives insights for tailoring thermal conductivity and enhancing the ZT of silicon to 1 for its use in thermoelectrics

MICROSTRUCTURAL PROPERTIES OF NC-Si/SiO2 FILMS IN SITU GROWN BY REACTIVE MAGNETRON CO-SPUTTERING

2012 ◽  
Vol 11 (06) ◽  
pp. 1240035
Author(s):  
WANBING LU ◽  
SHAOGANG GUO ◽  
JIANTAO WANG ◽  
YUN LI ◽  
XINZHAN WANG ◽  
...  
Keyword(s):  
Deposition Rate ◽  
Silicon Oxide ◽  
Low Cost ◽  
Nanocrystalline Silicon ◽  
Reactive Magnetron ◽  
Microstructural Properties ◽  
Hydrogen Atoms ◽  
Glass Substrates ◽  
Average Size

Nanocrystalline silicon embedded in silicon oxide (nc- Si/SiO2 ) films have been in situ grown at a low substrate temperature of 300°C by reactive magnetron co-sputtering of Si and SiO2 targets in a mixed Ar/H2 discharge. The influences of H2 flow rate (F H ) on the microstructural properties of the deposited nc- Si/SiO2 films were investigated. The results of XRD and the deposition rate of nc- Si/SiO2 films show that the introduction of H2 contributes to the growth of nc- Si grains in silicon oxide matrix. With further increasing F H , the average size of nc- Si grains increases and the deposition rate of nc- Si/SiO2 films decreases gradually. Fourier transform infrared spectra analyses reveal that introduction of hydrogen contributes to the phase separation of nc- Si and SiO x in the deposited films. Moreover, the Si–O 4-n Si n(n = 0, 1) concentration of the deposited nc- Si/SiO2 films reduces with the increase of F H , while that of Si – O 4-n Si n(n = 2, 3) concentration increases. These results can be explained by that active hydrogen atoms increase the probability of reducing oxygen from precursor in the plasma and prompting oxygen desorption from the growing surface. This low-temperature procedure for preparing nc- Si/SiO2 films opens up the possibility of fabricating the silicon-based thin-film solar cells onto low-cost glass substrates using nc- Si/SiO2 films.

scholarly journals Synthesis and Thermoelectric Properties of C60/Cu2GeSe3Composites

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Degang Zhao ◽  
Jiai Ning ◽  
Shuyu Li ◽  
Min Zuo
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Grain Boundaries ◽  
Ball Milling ◽  
Thermoelectric Properties ◽  
Phonon Scattering ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Average Size

Nanosized C60powder was sufficiently incorporated with Cu2GeSe3powder by ball milling and C60/Cu2GeSe3composites were prepared by spark plasma sintering. C60distributed uniformly in the form of clusters and the average size of cluster was lower than 1 μm. With the addition of C60increasing, the electrical resistivity and Seebeck coefficient of C60/Cu2GeSe3composites increased while the thermal conductivity decreased significantly which resulted from the phonon scattering by C60clusters locating on the grain boundaries of Cu2GeSe3matrix. The maximumZTof 0.20 was achieved at 700 K for 0.9% C60/Cu2GeSe3sample.

Influence of Addition of Alumina Nanoparticles on Thermoelectric Properties of Higher Manganese Silicide

2012 ◽  
Vol 1490 ◽  
pp. 127-132 ◽  
Author(s):  
Takashi Itoh ◽  
Naoki Ono
Keyword(s):  
Thermal Conductivity ◽  
Grain Boundary ◽  
Thermoelectric Properties ◽  
Lattice Thermal Conductivity ◽  
Waste Heat ◽  
Low Cost ◽  
Thermoelectric Performance ◽  
Alumina Nanoparticles ◽  
Higher Manganese Silicide ◽  
Manganese Silicide

ABSTRACTHigher manganese silicide (HMS) is a low-cost and eco-friendly thermoelectric material available for recovering waste heat of 500 to 900 K. In this research, we tried to uniformly disperse the alumina nanoparticles (ANPs) in the HMS matrix to reduce the thermal conductivity and to improve the thermoelectric performance. Influence of addition of ANPs on the thermoelectric properties was investigated. It was confirmed that ANPs were uniformly dispersed in the HMS grain boundary. The lattice thermal conductivity was reduced by adding ANPs. As a result, the maximum thermoelectric performance of ZT=0.58 was achieved at about 800 K by adding 1 vol% of ANPs. The performance of ANPs-added HMS was improved about 25 %.

scholarly journals Submicron Features in Higher Manganese Silicide

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Yatir Sadia ◽  
Mor Elegrably ◽  
Oren Ben-Nun ◽  
Yossi Marciano ◽  
Yaniv Gelbstein
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Hot Pressing ◽  
Alternative Energy ◽  
Low Cost ◽  
Electrical Energy ◽  
Thermoelectric Effects ◽  
Higher Manganese Silicide ◽  
Low Thermal Conductivity ◽  
Manganese Silicide

The world energy crisis had increased the demand for alternative energy sources and as such is one of the topics at the forefront of research. One way for reducing energy consumption is by thermoelectricity. Thermoelectric effects enable direct conversion of thermal into electrical energy. Higher manganese silicide (HMS, MnSi1.75) is one of the promising materials for applications in the field of thermoelectricity. The abundance and low cost of the elements, combined with good thermoelectric properties and high mechanical and chemical stability at high temperatures, make it very attractive for thermoelectric applications. Recent studies have shown that Si-rich HMS has improved thermoelectric properties. The most interesting of which is the unusual reduction in thermal conductivity. In the current research, transmission (TEM) and scanning (SEM) electron microscopy as well as X-ray diffraction methods were applied for investigation of the govern mechanisms resulting in very low thermal conductivity values of an Si-rich HMS composition, following arc melting and hot-pressing procedures. In this paper, it is shown that there is a presence of sub-micron dislocations walls, stacking faults, and silicon and HMS precipitates inside each other apparent in the matrix, following a high temperature (0.9 Tm) hot pressing for an hour. These are not just responsible for the low thermal conductivity values observed but also indicate the ability to create complicate nano-structures that will last during the production process and possibly during the application.

Thermoelectric Properties of PbSr(Se,Te)-Based Low Dimensional Structures

2000 ◽  
Vol 626 ◽  
Author(s):  
Harald Beyer ◽  
Joachim Nurnus ◽  
Harald Böttner ◽  
Armin Lambrecht ◽  
Lothar Schmitt ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Evaluation Method ◽  
Interband Transition ◽  
Multiple Quantum Well ◽  
Calculated Data ◽  
Multiple Quantum ◽  
Ir Transmission ◽  
Low Dimensional

ABSTRACTThermoelectric properties of low dimensional structures based on PbTe/PbSrTe-multiple quantum-well (MQW)-structures with regard to the structural dimensions, doping profiles and levels are presented. Interband transition energies and barrier band-gap are determined from IR-transmission spectra and compared with Kronig-Penney calculations. The influence of the data evaluation method to obtain the 2D power factor will be discussed. The thermoelectrical data of our layers show a more modest enhancement in the power factor σS2 compared with former publications and are in good agreement with calculated data from Broido et al. [5]. The maximum allowed doping level for modulation doped MQW structures is determined. Thermal conductivity measurements show that a ZT enhancement can be achieved by reducing the thermal conductivity due to interface scattering. Additionally promising lead chalcogenide based superlattices for an increased 3D figure of merit are presented.

Structure and Thermoelectric Properties of New Quaternary Tin and Lead Bismuth Selenides, K1+xM4-2xBi7+xSe15 (M = Sn, Pb) and K1+xSn5-xBi11+xSe22

2000 ◽  
Vol 626 ◽  
Author(s):  
Antje Mrotzek ◽  
Kyoung-Shin Choi ◽  
Duck-Young Chung ◽  
Melissa A. Lane ◽  
John R. Ireland ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Single Crystal ◽  
Thermoelectric Properties ◽  
Three Dimensional ◽  
Structure Type ◽  
Narrow Gap ◽  
Low Thermal Conductivity ◽  
Seebeck Coefficients ◽  
Metal Atoms ◽  
Anionic Framework

ABSTRACTWe present the structure and thermoelectric properties of the new quaternary selenides K1+xM4–2xBi7+xSe15 (M = Sn, Pb) and K1-xSn5-xBi11+xSe22. The compounds K1+xM4-2xBi7+xSe15 (M= Sn, Pb) crystallize isostructural to A1+xPb4-2xSb7+xSe15 with A = K, Rb, while K1-xSn5-xBi11+xSe22 reveals a new structure type. In both structure types fragments of the Bi2Te3-type and the NaCl-type are connected to a three-dimensional anionic framework with K+ ions filled tunnels. The two structures vary by the size of the NaCl-type rods and are closely related to β-K2Bi8Se13 and K2.5Bi8.5Se14. The thermoelectric properties of K1+xM4-2xBi7+xSe15 (M = Sn, Pb) and K1-xSn5-xBi11+xSe22 were explored on single crystal and ingot samples. These compounds are narrow gap semiconductors and show n-type behavior with moderate Seebeck coefficients. They have very low thermal conductivity due to an extensive disorder of the metal atoms and possible “rattling” K+ ions.

scholarly journals Microstructure and Thermoelectric Properties of (Bi0.48Sb1.52)Te3 Thick Films Prepared with Tape Casting Method

Electronics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 140
Author(s):  
Lichen Liu ◽  
Ziping Cao ◽  
Min Chen ◽  
Jun Jiang
Keyword(s):  
Thermoelectric Properties ◽  
Low Cost ◽  
Thick Films ◽  
Tape Casting ◽  
Casting Process ◽  
Casting Method ◽  
Glass Substrates ◽  
Conductive Films ◽  
Casting Technology

This paper reports the fabrication and characterization of (Bi0.48Sb1.52)Te3 thick films using a tape casting process on glass substrates. A slurry of thermoelectric (Bi0.48Sb1.52)Te3 was developed and cured thick films were annealed in a vacuum chamber at 500–600 °C. The microstructure of these films was analyzed, and the Seebeck coefficient and electric conductivity were tested. It was found that the subsequent annealing process must be carefully designed to achieve good thermoelectric properties of these samples. Conductive films were obtained after annealing and led to acceptable thermoelectric performance. While the properties of these initial materials are not at the level of bulk materials, this work demonstrates that the low-cost tape casting technology is promising for fabricating thermoelectric modules for energy conversion.

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