Nanostructured Silicon-based Composites for High Temperature Thermoelectric Applications

2010 ◽  
Vol 1267 ◽  
Author(s):  
Sabah Bux ◽  
Richard B Kaner ◽  
Jean-Pierre Fleurial
Keyword(s):  
Silicon Germanium ◽  
Waste Heat ◽  
Low Cost ◽  
Electric Transport ◽  
High Pressure Sintering ◽  
High Carrier Mobility ◽  
High Carrier ◽  
Low Toxicity ◽  
Silicon Based ◽  
The Impact

AbstractRecently nanostructured bulk silicon and silicon-germanium have achieved large increases in the thermoelectric figure of merit (ZT). The ZT enhancement is attributed to a significant reduction in the lattice thermal conductivity while maintaining relatively high carrier mobility. Silicon-based thermoelectric devices are attractive due to their low-toxicity, thermal stability, low density, relative abundance and low cost of production. Although significant enhancements in ZT have been achieved using the nanostructuring route, additional decoupling of the thermal and electric transport terms is still necessary in order for silicon-based materials to be viable for thermoelectric applications such as waste heat recovery or radioisotope thermoelectric generators. It is theorized that additional increases in ZT could be achieved by forming composites with nanostructured inert inclusions to further scatter the heat-carrying phonons. Here we present the impact of insulating and conductive nanoparticle composites on ZT. The nanostructured composites are formed via ball milling and high pressure sintering of the nanoparticles. The thermoelectric properties and microstructure of the silicon-based composites are discussed.

scholarly journals Achieving High Thermoelectric Performance in Rare-Earth Element-Free CaMg2Bi2 with High Carrier Mobility and Ultralow Lattice Thermal Conductivity

Research ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Muchun Guo ◽  
Fengkai Guo ◽  
Jianbo Zhu ◽  
Li Yin ◽  
Qian Zhang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Materials ◽  
Carrier Mobility ◽  
Lattice Thermal Conductivity ◽  
Low Cost ◽  
Thermoelectric Performance ◽  
Widespread Application ◽  
Compatibility Factor ◽  
High Carrier Mobility ◽  
High Carrier

CaMg2Bi2-based compounds, a kind of the representative compounds of Zintl phases, have uniquely inherent layered structure and hence are considered to be potential thermoelectric materials. Generally, alloying is a traditional and effective way to reduce the lattice thermal conductivity through the mass and strain field fluctuation between host and guest atoms. The cation sites have very few contributions to the band structure around the fermi level; thus, cation substitution may have negligible influence on the electric transport properties. What is more, widespread application of thermoelectric materials not only desires high ZT value but also calls for low-cost and environmentally benign constituent elements. Here, Ba substitution on cation site achieves a sharp reduction in lattice thermal conductivity through enhanced point defects scattering without the obvious sacrifice of high carrier mobility, and thus improves thermoelectric properties. Then, by combining further enhanced phonon scattering caused by isoelectronic substitution of Zn on the Mg site, an extraordinarily low lattice thermal conductivity of 0.51 W m-1 K-1 at 873 K is achieved in (Ca0.75Ba0.25)0.995Na0.005Mg1.95Zn0.05Bi1.98 alloy, approaching the amorphous limit. Such maintenance of high mobility and realization of ultralow lattice thermal conductivity synergistically result in broadly improvement of the quality factor β. Finally, a maximum ZT of 1.25 at 873 K and the corresponding ZTave up to 0.85 from 300 K to 873 K have been obtained for the same composition, meanwhile possessing temperature independent compatibility factor. To our knowledge, the current ZTave exceeds all the reported values in AMg2Bi2-based compounds so far. Furthermore, the low-cost and environment-friendly characteristic plus excellent thermoelectric performance also make the present Zintl phase CaMg2Bi2 more competitive in practical application.

Analytical Modeling of Carbon Nanoparticle-Based Symmetric p–n Junction

2019 ◽  
Vol 11 (11) ◽  
pp. 1031-1035
Author(s):  
Mohammad Majidi ◽  
Mohammad Taghi Ahmadi ◽  
Meisam Rahmani
Keyword(s):  
Carrier Mobility ◽  
High Surface ◽  
Scalar Potential ◽  
High Surface Area ◽  
Nanoscale Devices ◽  
Carbon Nanoparticle ◽  
Bipolar Technology ◽  
High Carrier Mobility ◽  
High Carrier ◽  
Silicon Based

Outstanding physical and electrical properties such as quantum transport, high carrier mobility, excellent electrical and thermal conductivity, high surface area, good optical transparency, strong mechanical strength and easy fabrication make carbon nanoparticles appropriate on nanoelectronic applications. Carbon nanoparticle based p–n junction, as a fundamental structure of nanoscale devices, is analytically presented in this study. The carbon nanoparticle p–n interface reveals an improved transport along the junction in comparison with the conventional p–n junction. Controlling the doping of p–n junction based device partially permit the foundation of carbon nanoparticle based bipolar technology and can overcome application of current in silicon based technology. This paper analytically demonstrates findings on electric field, space charge region width, scalar potential, built-in potential and transport along carbon nanoparticle based p–n junction. The uniqueness of this method is to create a well identified carbon nanoparticle based p–n junction which opens new opportunities for researching high field transport limit in nanoscale devices.

Large grained single-crystalline-like germanium thin film on flexible Ni–W tape

RSC Advances ◽  
2014 ◽  
Vol 4 (40) ◽  
pp. 21042-21048 ◽  
Author(s):  
Pavel Dutta ◽  
Monika Rathi ◽  
Yao Yao ◽  
Ying Gao ◽  
Goran Majkic ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Carrier Mobility ◽  
Low Cost ◽  
Single Crystalline ◽  
Metal Foils ◽  
Roll To Roll ◽  
High Carrier Mobility ◽  
High Carrier

Roll-to-roll growth of single-crystalline-like germanium thin films with high carrier mobility on low-cost flexible Ni–W metal foils has been demonstrated.

scholarly journals Review of Polarization Optical Devices Based on Graphene Materials

2020 ◽  
Vol 21 (5) ◽  
pp. 1608 ◽  
Author(s):  
Shijie Zhang ◽  
Zongwen Li ◽  
Fei Xing
Keyword(s):  
Response Spectrum ◽  
Optical Devices ◽  
Polarization Dependence ◽  
Research Progress ◽  
Absorption Enhancement ◽  
Broadband Absorption ◽  
Polarization Characteristics ◽  
High Carrier Mobility ◽  
High Carrier ◽  
Silicon Based

Graphene has received extensive scholarly attention for its extraordinary optical, electrical, and physicochemical properties, as well as its compatibility with silicon-based semiconductor processes. As a unique two-dimensional atomic crystal material, graphene has excellent mechanical properties, ultra-high carrier mobility, ultra-wide optical response spectrum, and strong polarization dependence effect, which make it have great potential in new optical and polarization devices. A series of new optical devices that are based on graphene have been developed, showing excellent performance and broad application prospects. In this paper, the recent research progress of polarizers, sensors, modulators, and detectors that are based on the polarization characteristics of graphene is reviewed. In particular, the polarization dependence effect and broadband absorption enhancement of graphene under total reflection structure are emphasized, which enhance the interaction between graphene and light and then provide a new direction for research of graphene polarization devices.

High-k Gate Dielectrics on Silicon and Germanium: Impact of Surface Preparation

2005 ◽  
Vol 103-104 ◽  
pp. 3-6 ◽  
Author(s):  
Alessio Beverina ◽  
M.M. Frank ◽  
H. Shang ◽  
S. Rivillon ◽  
F. Amy ◽  
...  
Keyword(s):  
Hafnium Oxide ◽  
Gate Dielectrics ◽  
Surface Preparation ◽  
Semiconductor Surface ◽  
High K ◽  
Prime Concern ◽  
High Carrier Mobility ◽  
High Carrier ◽  
Silicon And Germanium ◽  
The Impact

We review the impact of semiconductor surface preparation on the performance of metal-oxidesemiconductor field-effect transistor (MOSFET) gate stacks. We discuss high-permittivity dielectrics such as hafnium oxide and aluminum oxide on silicon and on the high carrier mobility substrate germanium. On Si, scaling of the gate stack is the prime concern. On Ge, fundamental issues of chemical and electrical passivation need to be resolved. Surface treatments considered include oxidation, nitridation, hydrogenation, chlorination, and organic functionalization.

Computer simulation study about the dependence of amorphous silicon photonic waveguides efficiency on the material quality

2020 ◽  
Vol 90 (3) ◽  
pp. 30502
Author(s):  
Alessandro Fantoni ◽  
João Costa ◽  
Paulo Lourenço ◽  
Manuela Vieira
Keyword(s):  
Amorphous Silicon ◽  
High Throughput Screening ◽  
Simulation Analysis ◽  
Low Cost ◽  
Deposition Process ◽  
Large Area ◽  
Sidewall Roughness ◽  
Sensing Applications ◽  
Fabrication Defects ◽  
The Impact

Amorphous silicon PECVD photonic integrated devices are promising candidates for low cost sensing applications. This manuscript reports a simulation analysis about the impact on the overall efficiency caused by the lithography imperfections in the deposition process. The tolerance to the fabrication defects of a photonic sensor based on surface plasmonic resonance is analysed. The simulations are performed with FDTD and BPM algorithms. The device is a plasmonic interferometer composed by an a-Si:H waveguide covered by a thin gold layer. The sensing analysis is performed by equally splitting the input light into two arms, allowing the sensor to be calibrated by its reference arm. Two different 1 × 2 power splitter configurations are presented: a directional coupler and a multimode interference splitter. The waveguide sidewall roughness is considered as the major negative effect caused by deposition imperfections. The simulation results show that plasmonic effects can be excited in the interferometric waveguide structure, allowing a sensing device with enough sensitivity to support the functioning of a bio sensor for high throughput screening. In addition, the good tolerance to the waveguide wall roughness, points out the PECVD deposition technique as reliable method for the overall sensor system to be produced in a low-cost system. The large area deposition of photonics structures, allowed by the PECVD method, can be explored to design a multiplexed system for analysis of multiple biomarkers to further increase the tolerance to fabrication defects.

Advancing dairy farming profitability through research

2001 ◽  
pp. 17-22
Author(s):  
J.R. Caradus ◽  
D.A. Clark
Keyword(s):  
Research And Development ◽  
Dairy Cow ◽  
Low Cost ◽  
Pasture Management ◽  
Nitrogen Fertiliser ◽  
Grass Endophyte ◽  
Forage Species ◽  
Development Outcomes ◽  
Dairy Cow Nutrition ◽  
The Impact

The New Zealand dairy industry recognises that to remain competitive it must continue to invest in research and development. Outcomes from research have ensured year-round provision of low-cost feed from pasture while improving productivity. Some of these advances, discussed in this paper, include the use of white clover in pasture, understanding the impacts of grass endophyte, improved dairy cow nutrition, the use of alternative forage species and nitrogen fertiliser to improve productivity, demonstration of the impact of days-in-milk on profitability, and the use of feed budgeting and appropriate pasture management. Keywords: dairy, profitability, research and development

Sign in / Sign up

Export Citation Format

Share Document