scholarly journals n-type thermoelectric material Mg2Sn0.75Ge0.25 for high power generation

2015 ◽  
Vol 112 (11) ◽  
pp. 3269-3274 ◽  
Author(s):  
Weishu Liu ◽  
Hee Seok Kim ◽  
Shuo Chen ◽  
Qing Jie ◽  
Bing Lv ◽  
...  
Keyword(s):  
Power Generation ◽  
Output Power ◽  
High Power ◽  
Figure Of Merit ◽  
High Efficiency ◽  
Waste Heat ◽  
Flow Equation ◽  
Thermoelectric Figure ◽  
One Dimensional ◽  
High Power Factor

Thermoelectric power generation is one of the most promising techniques to use the huge amount of waste heat and solar energy. Traditionally, high thermoelectric figure-of-merit, ZT, has been the only parameter pursued for high conversion efficiency. Here, we emphasize that a high power factor (PF) is equivalently important for high power generation, in addition to high efficiency. A new n-type Mg2Sn-based material, Mg2Sn0.75Ge0.25, is a good example to meet the dual requirements in efficiency and output power. It was found that Mg2Sn0.75Ge0.25 has an average ZT of 0.9 and PF of 52 μW⋅cm−1⋅K−2 over the temperature range of 25–450 °C, a peak ZT of 1.4 at 450 °C, and peak PF of 55 μW⋅cm−1⋅K−2 at 350 °C. By using the energy balance of one-dimensional heat flow equation, leg efficiency and output power were calculated with Th = 400 °C and Tc = 50 °C to be of 10.5% and 6.6 W⋅cm−2 under a temperature gradient of 150 °C⋅mm−1, respectively.

Heat Transport in Superlattices and Nanocomposites for Thermoelectric Applications

2006 ◽  
Vol 46 ◽  
pp. 104-110 ◽  
Author(s):  
Gang Chen
Keyword(s):  
Thermal Conductivity ◽  
Figure Of Merit ◽  
Large Scale ◽  
Energy Transport ◽  
High Efficiency ◽  
Waste Heat ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure

Energy transport in nanostructures differs significantly from macrostructures because of classical and quantum size effects on energy carriers. Experimental results show that the thermal conductivity values of nanostructures such as superlattices are significantly lower than that of their bulk constituent materials. The reduction in thermal conductivity led to a large increase in the thermoelectric figure of merit in several superlattice systems. Materials with a large thermoelectric figure of merit can be used to develop efficient solid-state devices that convert waste heat into electricity. Superlattices grown by thin-film deposition techniques, however, are not suitable for large scale applications. Nanocomposites represent one approach that can lead to high thermoelectric figure merit. This paper reviews the current understanding of thermal conductivity reduction mechanisms in superlattices and presents theoretical studies on thermoelectric properties in semiconducting nanocomposites, aiming at developing high efficiency thermoelectric energy conversion materials.

scholarly journals Realizing a 14% single-leg thermoelectric efficiency in GeTe alloys

2021 ◽  
Vol 7 (19) ◽  
pp. eabf2738
Author(s):  
Zhonglin Bu ◽  
Xinyue Zhang ◽  
Bing Shan ◽  
Jing Tang ◽  
Hongxia Liu ◽  
...  
Keyword(s):  
High Performance ◽  
Figure Of Merit ◽  
High Efficiency ◽  
Phonon Scattering ◽  
Waste Heat ◽  
Chemical Diffusion ◽  
Thermoelectric Device ◽  
Thermoelectric Efficiency ◽  
Good Service ◽  
Thermoelectric Figure

GeTe alloys have recently attracted wide attention as efficient thermoelectrics. In this work, a single-leg thermoelectric device with a conversion efficiency as high as 14% under a temperature gradient of 440 K was fabricated on the basis of GeTe-Cu2Te-PbSe alloys, which show a peak thermoelectric figure of merit (zT) > 2.5 and an average zT of 1.8 within working temperatures. The high performance of the material is electronically attributed to the carrier concentration optimization and thermally due to the strengthened phonon scattering, the effects of which all originate from the defects in the alloys. A design of Ag/SnTe/GeTe contact successfully enables both a prevention of chemical diffusion and an interfacial contact resistivity of 8 microhm·cm2 for the realization of highly efficient devices with a good service stability/durability. Not only the material’s high performance but also the device’s high efficiency demonstrated the extraordinariness of GeTe alloys for efficient thermoelectric waste-heat recovery.

scholarly journals Thermoelectric properties of Nb-doped Sr1−x (La0.5Na0.5) x TiO3 perovskites

2021 ◽  
Author(s):  
Makoto Tachibana ◽  
Ahmad Rifqi Muchtar ◽  
Takao Mori
Keyword(s):  
Thermal Conductivity ◽  
Solid Solution ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
High Power ◽  
Figure Of Merit ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
High Power Factor ◽  
Nb Doping

Abstract We report the thermal conductivity (κ) of perovskite Sr1−x(La0.5Na0.5)xTiO3 (0 ≤ x ≤ 1) and the thermoelectric properties of Nb-doped samples for x = 0.1 and 0.2. The κ of the solid solution shows a distinct minimum near the cubic-tetragonal phase boundary at x = 0.2, where the value becomes close to the minimum theoretical κ. Nb doping to x = 0.2 retains the high power factor found in Nb-doped SrTiO3, but also raises the κ to result in a thermoelectric figure of merit of 0.24 at 773 K.

Enhanced Thermoelectric Figure of Merit in P-Type DDy(Fe1-XCox)4Sb12

2011 ◽  
Vol 170 ◽  
pp. 240-243 ◽  
Author(s):  
Gerda Rogl ◽  
Andriy Grytsiv ◽  
Peter Rogl ◽  
Ernst Bauer ◽  
Michael Zehetbauer
Keyword(s):  
Power Generation ◽  
Thermoelectric Power ◽  
Figure Of Merit ◽  
High Efficiency ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
Thermoelectric Power Generation ◽  
Temperature Range ◽  
P Type ◽  
Co Concentrations

Thermoelectric (TE) properties of skutterudites DDy(Fe1-xCox)4Sb12 for 0.2  x 0.3 were studied in the temperature range from 300 K to 800 K and compared with values for x = 0. Didymium (DD, 4.76 mass % Pr and 95.24 mass % Nd) was used as natural double filler. At Co-concentrations 0.225  x  0.25 maximum TE-performance was obtained with impressive power-factors (4.5 mW/mK2) and ZTs (ZT1.2 at 700 K). Furthermore these skutterudites maintain the high ZT over a broad temperature range providing an excellent p-leg for high-efficiency thermoelectric power generation.

Output power feedforward technique applied to a high power factor rectifier with high frequency transformer

2013 ◽  
Author(s):  
Julio Cesar Secolo Ganacim ◽  
Martin Breus Meier ◽  
Alceu Andre Badin ◽  
Roger Gules ◽  
Eduardo Felix Ribeiro Romaneli ◽  
...  
Keyword(s):  
Output Power ◽  
Power Factor ◽  
High Power ◽  
High Frequency ◽  
High Frequency Transformer ◽  
High Power Factor

Theoretical Modeling of Thermoelectricity in Bi Nanowires

1998 ◽  
Vol 545 ◽  
Author(s):  
X. Sun ◽  
Z. Zhang ◽  
G. Dresselhaus ◽  
M. S. Dresselhaus ◽  
J. Y. Ying ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Theoretical Model ◽  
Quantum Confinement ◽  
Figure Of Merit ◽  
Wire Diameter ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
Crystalline Orientation ◽  
One Dimensional ◽  
Bismuth Nanowires

AbstractBismuth as a semimetal is not a good thermoelectric material in bulk form because of the approximate cancellation between the electron and hole contributions. However, quantum confinement can be introduced by making Bi nanowires to move the lowest conduction subband edge up and the highest valence subband edge down to get a one-dimensional (1D) semiconductor at some critical wire diameter dc. A theoretical model based on the basic band structure of bulk Bi is developed to predict the dependence of these quantities on wire diameter and on the crystalline orientation of the bismuth nanowires. Numerical modeling is performed for trigonal, binary and bisectrix crystal orientations. By carefully tailoring the Bi wire diameter and carrier concentration, substantial enhancement in the thermoelectric figure of merit is expected for small nanowire diameters.

High efficiency GeTe-based materials and modules for thermoelectric power generation

2021 ◽  
Author(s):  
Tong Xing ◽  
Qingfeng Song ◽  
Pengfei Qiu ◽  
Qihao Zhang ◽  
Ming Gu ◽  
...  
Keyword(s):  
Power Generation ◽  
Thermoelectric Power ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
High Efficiency ◽  
Waste Heat ◽  
Thermoelectric Performance ◽  
Thermoelectric Generators ◽  
Thermoelectric Power Generation

GeTe-based materials have a great potential to be used in thermoelectric generators for waste heat recovery due to their excellent thermoelectric performance, but their module research is greatly lagging behind...

A Novel High Power Factor Soft-Switching Converter

2012 ◽  
Vol 433-440 ◽  
pp. 5549-5555
Author(s):  
Yun Tao Yue ◽  
Yan Lin
Keyword(s):  
Power Factor ◽  
High Power ◽  
Power Supply ◽  
High Efficiency ◽  
Soft Switching ◽  
Switching Converter ◽  
Turn On ◽  
High Power Factor ◽  
Power Factor Corrector ◽  
Zero Voltage

A novel scheme of low power communication power supply with high power factor and soft-switching is presented, a power factor corrector and dc/dc converter of passive lossless soft-switching is based on a ML4803 IC control. DC/DC converter introduces a novel two-transistor forward soft-switching technique, which realizes zero-voltage turn-on and turn-off, with no additional switches. a communication power supply module is developed in this paper. It has the characteristics of rapid dynamic response, high power factor, high efficiency and small bulk ect.

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