Performance and Testing of Novel Quantum Well Thermoelectric Devices

2010 ◽  
Author(s):  
Velimir Jovanovic ◽  
Saeid Ghamaty ◽  
Norbert B. Elsner ◽  
Daniel Krommenhoek ◽  
John C. Bass
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Quantum Well ◽  
Seebeck Coefficient ◽  
Coefficient Of Performance ◽  
Test Technique ◽  
Low Thermal Conductivity ◽  
Barrier Materials ◽  
Te Modules ◽  
Conversion Efficiencies

New nano-structured thermoelectric (TE) materials have been developed and fabricated that have much higher conversion efficiencies than the state-of-the-art (SOTA) bulk thermoelectrics. In these new quantum well (QW) materials, the carrier and barrier materials (in this case SiGe and Si) are confined in alternating layers less than 10 nm thick, and this confinement has been shown to result in greatly improved TE properties (Seebeck coefficient, electrical resistivity and thermal conductivity) leading to higher TE Figure of Merit, ZT, conversion efficiencies and Coefficient of Performance (COP) for cooling applications than for SOTA thermoelectrics. From the most recent QW test data, ZTs greater than 3 at room temperature have been obtained which constitutes a significant improvement over the SOTA bulk thermoelectrics which have ZTs less than 1. QW materials have the best measured TE power factor (Seebeck coefficient squared divided by electrical resistivity) and, combined with low thermal conductivity substrates, should provide very high efficiency TE modules. The QW TE materials with ZTs greater than 3 lead to conversion efficiencies greater than 20 percent, which allows for much wider commercial applications, particularly in the applications such as the waste-heat recovery from truck engines, refrigeration, and air conditioning, where the SOTA bulk TE modules were shown to be technically feasible but economically unjustified due to low conversion efficiencies. With higher efficiency QW materials, these applications become economically attractive. The above mentioned QW TE ZTs include the effect of the substrate which degrades the overall performance, and a new test technique was developed that eliminates the effect of the substrate and for just the QW films, ZTs greater than 6 have been measured. This illustrated the importance of using a low thermal conductivity substrate in order to achieve good TE performance. In a recent QW test, a conversion efficiency corresponding to 62 percent of the Carnot efficiency was measured and this is believed to be the highest such value ever measured for a TE material. For power generation applications, QW TE generators can be designed for capacities ranging from milliwatts to kilowatts and for cooling applications with capacities ranging from watts to several tons of refrigeration. The paper discusses the effects of the thermal and electrical contact resistances and of substrate thermal conductivity on the TE performance, the status of the prototype QW TE generators and coolers being designed and fabricated, and the latest test results.

Properties and Performance of Quantum Well Thermoelectric Materials

2010 ◽  
Author(s):  
Velimir Jovanovic ◽  
Saeid Ghamaty ◽  
Norbert B. Elsner ◽  
Daniel Krommenhoek
Keyword(s):  
Thermal Conductivity ◽  
Seebeck Coefficient ◽  
Quantum Wells ◽  
Air Conditioning ◽  
High Efficiency ◽  
Waste Heat ◽  
Test Technique ◽  
And Performance ◽  
Te Modules ◽  
Conversion Efficiencies

New and more efficient thermoelectric (TE) materials that make use of nanotechnology have been developed. These new materials, called quantum wells (QW), are composed of alternating layers of 10 nm thick silicon and SiGe films. They can be deposited by various techniques and magnetron sputtering was used to obtain uniform layered structures that exhibited no degradation of the TE properties or microstructure after thermal aging. For QW thin films, the heat and current flow are “in plane” and in this orientation all of the thermoelectric properties (the Seebeck coefficient, electrical resistivty, and the thermal conductivity) are improved to increase the TE Figure of Merit, ZT (see equation 3, p. 4, for the definition of Z). From the most recent QW test data, ZTs greater than 3 at room temperature have been obtained which constitutes a significant improvement over the state-of-the-art (SOTA) bulk thermoelectrics which have ZTs less than 1. QW materials have the best measured TE power factor (Seebeck coefficient squared divided by electrical resistivity) and, combined with low thermal conductivity substrates, should provide very high efficiency TE modules. The QW TE materials with ZTs greater than 3 lead to conversion efficiencies greater than 20 percent, which allows for much wider commercial applications, particularly in the applications such as the waste-heat recovery from truck engines, refrigeration, and air conditioning, where the SOTA bulk TE modules were shown to be technically feasible but economically unjustified due to low conversion efficiencies. With higher efficiency QW materials, these applications become economically attractive. For the refrigeration and air conditioning applications, the QW TE materials are predicted to have higher coefficients of performance (COP) than the SOTA vapor compression systems, with the additional advantages of having no compressors, no moving parts, no refrigerants, no vibrations, no noise, and practically no maintenance. With such significant advantages, it is very important to have independent confirmation of the QW TE properties that lead to such improved performance. Three independent researchers have confirmed the previously measured QW TE properties using conventional test techniques, and a totally new test technique was developed to measure the TE properties and performance and the results provided yet another confirmation of the superior TE performance of the QW materials versus the SOTA bulk thermoelectrics. The temperature range for the applications is anticipated to be as low as −150C to the upper temperature of 1000C, with the power generation capacity ranging from milliwatts to kilowatts and cooling capacity ranging from watts to several tons of refrigeration.

Novel Nano-Structured High-Performance Thermoelectric Materials and Devices

2011 ◽  
Author(s):  
Velimir Jovanovic ◽  
Saeid Ghamaty ◽  
John C. Bass ◽  
Daniel Krommenhoek
Keyword(s):  
High Performance ◽  
Power Plants ◽  
Waste Heat ◽  
Coefficient Of Performance ◽  
Barrier Materials ◽  
Macro Scale ◽  
Commercial Applications ◽  
Te Modules ◽  
Te Material ◽  
Conversion Efficiencies

Recent developments of high-performance nano-structured thermoelectric (TE) materials show that these materials have much higher conversion efficiencies than the state-of-the-art (SOTA) thermoelectrics. In these new quantum well (QW) materials, the carrier and barrier materials (in this case SiGe and Si) are confined in alternating layers less than 10 nm thick, and this confinement has been shown to result in greatly improved TE properties (Seebeck coefficient, electrical resistivity and thermal conductivity) leading to higher TE Figure of Merit, ZT, conversion efficiencies and Coefficient of Performance (COP) for cooling applications than for SOTA bulk thermoelectrics. From the most recent QW test data, ZTs greater than 3 at room temperature have been obtained which constitutes a significant improvement over the SOTA bulk thermoelectrics which have ZTs less than 1. The QW TE materials with ZTs greater than 3 lead to conversion efficiencies greater than 20 percent and higher COPs than for the SOTA vapor-compression cooling systems, which allow for much wider commercial applications, particularly in the applications such as the waste-heat recovery from truck engines and power plants, refrigeration and air conditioning, where the SOTA bulk TE modules were shown to be technically feasible but economically unjustified due to low conversion efficiencies. With higher efficiency QW materials, these applications become economically attractive. In a recent QW test, a conversion efficiency corresponding to 60 percent of the Carnot efficiency was measured and this is believed to be the highest such value ever measured for a TE material. For power generation applications, QW TE generators can be designed for capacities ranging from milliwatts to kilowatts and for cooling applications with capacities ranging from watts to several tons of refrigeration. This involves the transition from the nano scale QW thin films to macro scale TE devices. This paper discusses the status of the prototype QW TE generators and coolers being designed and fabricated, and the latest test results.

Thermoelectric Properties and Power Generation of p–Ca3Co4O9 and n–Sr0.87La0.13TiO3 Thermoelectric Modules

2016 ◽  
Vol 675-676 ◽  
pp. 679-682 ◽  
Author(s):  
Kunchit Singsoog ◽  
Chanchana Thanachayanont ◽  
Anek Charoenphakdee ◽  
Tosawat Seetawan
Keyword(s):  
Thermal Conductivity ◽  
Power Generation ◽  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Maximum Output Power ◽  
Thermoelectric Module ◽  
Maximum Output ◽  
Te Modules ◽  
Matching Load

The Ca3Co4O9 (CCO) and Sr0.87La0.13TiO3 (SLTO) are good property of oxide thermoelectric (TE) materials. They synthesized by solid state reaction (SSR) method to study thermoelectric properties and fabrication of thermoelectric module. It was found that, synthesis of CCO shows that Seebeck coefficient, electrical resistivity, thermal conductivity and values are 130 μV K–1, 8.31 mΩ cm, 0.82 W m–1 K–1 and 0.08, respectively at 473 K. The Seebeck coefficient, electrical resistivity, thermal conductivity and ZT values of SLTO are –359 μV K–1, 2.9 mΩ m, 18.09 W m–1 K–1 and 1.13×10–3, respectively at 473 K. TE modules of CCO and SLTO were fabricated by ultra sonic soldering method. The power generation of TE modules were measured with temperature difference (ΔT) of 10–180 K. The 1 pair and 2 pairs TE modules for a maximum power generation of matching load are 19 k and 30 k, respectively. The maximum output power of 2 pairs TE module is larger than 1 pair TE module about two times.

Sticky thermoelectric materials for flexible thermoelectric modules to capture low-temperature waste heat

MRS Advances ◽  
2020 ◽  
Vol 5 (10) ◽  
pp. 481-487 ◽  
Author(s):  
Norifusa Satoh ◽  
Masaji Otsuka ◽  
Yasuaki Sakurai ◽  
Takeshi Asami ◽  
Yoshitsugu Goto ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Low Temperature ◽  
Waste Heat ◽  
Air Cooling ◽  
Conductive Adhesives ◽  
Hot Plate ◽  
Low Thermal Conductivity ◽  
Te Modules ◽  
P Type ◽  
Flexible Thermoelectric

ABSTRACTWe examined a working hypothesis of sticky thermoelectric (TE) materials, which is inversely designed to mass-produce flexible TE sheets with lamination or roll-to-roll processes without electric conductive adhesives. Herein, we prepared p-type and n-type sticky TE materials via mixing antimony and bismuth powders with low-volatilizable organic solvents to achieve a low thermal conductivity. Since the sticky TE materials are additionally injected into punched polymer sheets to contact with the upper and bottom electrodes in the fabrication process, the sticky TE modules of ca. 2.4 mm in thickness maintained temperature differences of ca. 10°C and 40°C on a hot plate of 40 °C and 120°C under a natural-air cooling condition with a fin. In the single-cell resistance analysis, we found that 75∼150-µm bismuth powder shows lower resistance than the smaller-sized one due to the fewer number of particle-particle interfaces in the electric pass between the upper and bottom electrodes. After adjusting the printed wiring pattern for the upper and bottom electrodes, we achieved 42 mV on a hot plate (120°C) with the 6 x 6 module having 212 Ω in the total resistance. In addition to the possibility of mass production at a reasonable cost, the sticky TE materials provide a low thermal conductivity for flexible TE modules to capture low-temperature waste heat under natural-air cooling conditions with fins for the purpose of energy harvesting.

Thermoelectric Properties of Semiconducting Intermetallic Compounds: FeGa3and RuGa3

2003 ◽  
Vol 793 ◽  
Author(s):  
Y. Amagai ◽  
A. Yamamoto ◽  
C. H. Lee ◽  
H. Takazawa ◽  
T. Noguchi ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
High Temperature ◽  
Seebeck Coefficient ◽  
Transport Properties ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
High Seebeck Coefficient

ABSTRACTWe report transport properties of polycrystalline TMGa3(TM = Fe and Ru) compounds in the temperature range 313K<T<973K. These compounds exhibit semiconductorlike behavior with relatively high Seebeck coefficient, electrical resistivity, and Hall carrier concentrations at room temperature in the range of 1017- 1018cm−3. Seebeck coefficient measurements reveal that FeGa3isn-type material, while the Seebeck coefficient of RuGa3changes signs rapidly from large positive values to large negative values around 450K. The thermal conductivity of these compounds is estimated to be 3.5Wm−1K−1at room temperature and decreased to 2.5Wm−1K−1for FeGa3and 2.0Wm−1K−1for RuGa3at high temperature. The resulting thermoelectric figure of merit,ZT, at 945K for RuGa3reaches 0.18.

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...

Thermoelectric Properties of Doped Iron Disilicide

2000 ◽  
Vol 626 ◽  
Author(s):  
Jun-ichi Tani ◽  
Hiroyasu Kido
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Measured Temperature ◽  
Iron Disilicide ◽  
Measured Temperature Range ◽  
Temperature Range

ABSTRACTIn order to investigate the thermoelectric properties of Re-doped β-FeSi2 (Fe1-xRexSi2), Ir-doped β-FeSi2 (Fe1-xIrxSi2), and Pt-doped β-FeSi2 (Fe1-xPtxSi2), the electrical resistivity, the Seebeck coefficient, and the thermal conductivity of these samples have been measured in the temperature range between 300 and 1150 K. Fe1-xRexSi2 is p-type, while Fe1-xIrxSi2 and Fe1-xPt xSi2 are n-type over the measured temperature range. The solubility limits of dopant are estimated to be 0.2at% for Fe1-xRexSi2, 0.5at% for Fe1-xIrxSi2, and 1.9at% for Fe1-xPtxSi2. A maximum ZT value of 0.14 was obtained for Fe1-xPt xSi2 (x=0.03) at the temperature 847 K.

High-temperature thermoelectric properties of W-substituted CaMnO3

2013 ◽  
Vol 1490 ◽  
pp. 3-8 ◽  
Author(s):  
Dimas S. Alfaruq ◽  
James Eilertsen ◽  
Philipp Thiel ◽  
Myriam H Aguirre ◽  
Eugenio Otal ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
High Temperature ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Soft Chemistry ◽  
Absolute Seebeck Coefficient

AbstractThe thermoelectric properties of W-substituted CaMn1-xWxO3-δ (x = 0.01, 0.03; 0.05) samples, prepared by soft chemistry, were investigated from 300 K to 1000 K and compared to Nb-substituted CaMn0.98Nb0.02O3-δ. All compositions exhibit both an increase in absolute Seebeck coefficient and electrical resistivity with temperature. Moreover, compared to the Nb-substituted sample, the thermal conductivity of the W-substituted samples was strongly reduced. This reduction is attributed to the nearly two times greater mass of tungsten. Consequently, a ZT of 0.19 was found in CaMn0.97W0.03O3-δ at 1000 K, which was larger than ZT exhibited by the 2% Nb-doped sample.

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