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1.
A thermopile sensor was processed on a glass substrate by electrodeposition of n-type bismuth telluride (Bi-Te) and p-type antimony telluride (Sb-Te) films. The n-type Bi-Te film electrodeposited at −50 mV in a 50 mM electrolyte with a Bi/(Bi + Te) mole ratio of 0.5 exhibited a Seebeck
coefficient of −51.6 μV/K and a power factor of 7.1 × 10−4 W/K2 · m. The p-type Sb-Te film electroplated at 20 mV in a 70 mM solution with an Sb/(Sb + Te) mole ratio of 0.9 exhibited a Seebeck coefficient
of 52.1 μV/K and a power factor of 1.7 × 10−4 W/K2 · m. A thermopile sensor composed of 196 pairs of the p-type Sb-Te and the n-type Bi-Te thin-film legs exhibited sensitivity of 7.3 mV/K. 相似文献
2.
C. Navone M. Soulier M. Plissonnier A. L. Seiler 《Journal of Electronic Materials》2010,39(9):1755-1759
In major applications, optimal power will be achieved when thermoelectric films are at least 100 μm thick. In this paper we demonstrate that screen-printing is an ideal method to deposit around 100 μm of (Bi,Sb)2(Te,Se)3-based films on a rigid or flexible substrate with high Seebeck coefficient value (90 μV K−1 to 160 μV K−1) using a low-temperature process. Conductive films have been obtained after laser annealing and led to acceptable thermoelectric
performance with a power factor of 0.06 μW K−2 cm−1. While these initial material properties are not at the level of bulk materials, the complete manufacturing process is cost-effective,
compatible with large surfaces, and affords a mass-production technique. 相似文献
3.
Chia-Jyi Liu Gao-Jhih Liu Chun-Wei Tsao Yo-Jhih Huang 《Journal of Electronic Materials》2009,38(7):1499-1503
We report on the successful hydrothermal synthesis of Bi0.5Sb1.5Te3, using water as the solvent. The products of the hydrothermally prepared Bi0.5 Sb1.5Te3 were hexagonal platelets with edges of 200–1500 nm and thicknesses of 30–50 nm. Both the Seebeck coefficient and electrical
conductivity of the hydrothermally prepared Bi0.5Sb1.5Te3 were larger than those of the solvothermally prepared counterpart. Hall measurements of Bi0.5Sb1.5Te3 at room temperature indicated that the charge carrier was p-type, with a carrier concentration of 9.47 × 1018 cm−3 and 1.42 × 1019 cm−3 for the hydrothermally prepared Bi0.5Sb1.5Te3 and solvothermally prepared sample, respectively. The thermoelectric power factor at 290 K was 10.4 μW/cm K2 and 2.9 μW/cm K2 for the hydrothermally prepared Bi0.5Sb1.5Te3 and solvothermally prepared sample, respectively. 相似文献
4.
B. N. Pantha R. Dahal J. Li J. Y. Lin H. X. Jiang G. Pomrenke 《Journal of Electronic Materials》2009,38(7):1132-1135
We report on the experimental investigation of the potential of InGaN alloys as thermoelectric (TE) materials. We have grown
undoped and Si-doped In0.3Ga0.7N alloys by metalorganic chemical vapor deposition and measured the Seebeck coefficient and electrical conductivity of the
grown films with the aim of maximizing the power factor (P). It was found that P decreases as electron concentration (n) increases. The maximum value for P was found to be 7.3 × 10−4 W/m K2 at 750 K in an undoped sample with corresponding values of Seebeck coefficient and electrical conductivity of 280 μV/K and 93␣(Ω cm)−1, respectively. Further enhancement in P is expected by improving the InGaN material quality and conductivity control by reducing background electron concentration. 相似文献
5.
Silver doped p-type Mg2Ge thin films were grown in situ at 773 K using magnetron co-sputtering from individual high-purity Mg and Ge targets. A sacrificial
base layer of silver of various thicknesses from 4 nm to 20 nm was initially deposited onto the substrate to supply Ag atoms,
which entered the growing Mg2Ge films by thermal diffusion. The addition of silver during film growth led to increased grain size and surface microroughness.
The carrier concentration increased from 1.9 × 1018 cm−3 for undoped films to 8.8 × 1018 cm−3 for the most heavily doped films, but it did not reach saturation. Measurements in the temperature range of T = 200–650 K showed a positive Seebeck coefficient for all the films, with maximum values at temperatures between 400 K and
500 K. The highest Seebeck coefficient of the undoped film was 400 μV K−1, while it was 280 μV K−1 for the most heavily doped film at ∼400 K. The electrical conductivity increased with silver doping by a factor of approximately
10. The temperature effects on power factors for the undoped and lightly doped films were very limited, while the effects
for the heavily doped films were substantial. The power factor of the heavily doped films reached a non-optimum value of ∼10−5 W cm−1 K−2 at 700 K. 相似文献
6.
Yong Liu Yuan-Hua Lin Jinle Lan Bo-Ping Zhang Wei Xu Ce-Wen Nan Hongmin Zhu 《Journal of Electronic Materials》2011,40(5):1083-1086
Polycrystalline In2O3 ceramics co-doped with Zn and Nd were prepared by the spark plasma sintering (SPS) process, and microstructure and thermoelectric
(TE) transport properties of the ceramics were investigated. Our results indicate that co-doping with Zn2+ and Nd3+ shows a remarkable effect on the transport properties of In2O3-based ceramics. Large electrical conductivity (~130 S cm−1) and thermopower (~220 μV K−1) can be observed in these In2O3-based ceramic samples. The maximum power factor (PF) reaches 5.3 × 10−4 W m−1 K−2 at 973 K in the In1.92Nd0.04Zn0.04O3 sample, with a highest ZT of ~0.25. 相似文献
7.
Tianbao Chen Ping Fan Zhuanghao Zheng Dongping Zhang Xingmin Cai Guangxing Liang Zhaokun Cai 《Journal of Electronic Materials》2012,41(4):679-683
Antimony and tellurium were deposited on BK7 glass using direct-current magnetron and radiofrequency magnetron cosputtering.
Antimony telluride thermoelectric thin films were synthesized with a heated substrate. The effects of substrate temperature
on the structure, surface morphology, and thermoelectric properties of the thin films were investigated. X-ray diffraction
patterns revealed that the thin films were well crystallized. c-Axis preferred orientation was observed in thin films deposited above 250°C. Scanning electron microscopy images showed hexagonal
crystallites and crystal grains of around 500 nm in thin film fabricated at 250°C. Energy-dispersive spectroscopy indicated
that a temperature of 250°C resulted in stoichiometric Sb2Te3. Sb2Te3 thin film deposited at room temperature exhibited the maximum Seebeck coefficient of 190 μV/K and the lowest power factor (PF), S
2
σ, of 8.75 × 10−5 W/mK2. When the substrate temperature was 250°C, the PF increased to its highest value of 3.26 × 10−3 W/mK2. The electrical conductivity and Seebeck coefficient of the thin film were 2.66 × 105 S/m and 113 μV/K, respectively. 相似文献
8.
Thermoelectric materials are attractive since they can recover waste heat directly in the form of electricity. In this study,
the thermoelectric properties of ternary rare-earth sulfides LaGd1+x
S3 (x = 0.00 to 0.03) and SmGd1+x
S3 (x = 0.00 to 0.06) were investigated over the temperature range of 300 K to 953 K. These sulfides were prepared by CS2 sulfurization, and samples were consolidated by pressure-assisted sintering to obtain dense compacts. The sintered compacts
of LaGd1+x
S3 were n-type metal-like conductors with a thermal conductivity of less than 1.7 W K−1 m−1. Their thermoelectric figure of merit ZT was improved by tuning the chemical composition (self-doping). The optimized ZT value of 0.4 was obtained in LaGd1.02S3 at 953 K. The sintered compacts of SmGd1+x
S3 were n-type hopping conductors with a thermal conductivity of less than 0.8 W K−1 m−1. Their ZT value increased significantly with temperature. In SmGd1+x
S3, the ZT value of 0.3 was attained at 953 K. 相似文献
9.
A PbTiO3/Ba0.85Sr0.15TiO3/PbTiO3 (PT/BST15/PT) sandwich thin film has been prepared on Pt/Ti/SiO2/Si substrates by an improved sol-gel technique. It is found that such films under rapid thermal annealing at 700°C crystallize
more favorably with the addition of a PbTiO3 layer. They possess a pure, perovskite-phase structure with a random orientation. The polarization-electric field (P-E) hysteresis
loop and current-voltage (I-V) characteristic curves reveal that a PT/BST15/PT film exhibits good ferroelectricity at room
temperature. However, no sharp peak, only a weak maximum, is observed in the curves of the dielectric constant versus temperature.
The dielectric constant, loss tangent, leakage current density at 20 kV/cm, remnant polarization, and coercive field of the
PT/BST15/PT film are 438, 0.025, 1.3 × 10−6 Acm−2, 2.46 μCcm−2, and 41 kVcm−1, respectively, at 25°C and 10 kHz. The PT/BST15/PT film is a candidate material for high sensitivity elements for uncooled,
infrared, focal plane arrays (UFPAs) to be used at near ambient temperature. 相似文献
10.
Shih-Yuan Lin Ying-Chung Chen Chih-Ming Wang Kuo-Sheng Kao Chih-Yuan Chan 《Journal of Electronic Materials》2009,38(3):453-459
Calcium copper titanium oxide (CaCu3Ti4O12, abbreviated to CCTO) films were deposited on Pt/Ti/SiO2/Si substrates at room temperature (RT) by radiofrequency magnetron sputtering. As-deposited CCTO films were treated by rapid
thermal annealing (RTA) at various temperatures and in various atmospheres. X-ray diffraction patterns and scanning electron
microscope (SEM) images demonstrated that the crystalline structures and surface morphologies of CCTO thin films were sensitive
to the annealing temperature and ambient atmosphere. Polycrystalline CCTO films could be obtained when the annealing temperature
was 700°C in air, and the grain size increased signifi- cantly with annealing in O2. The 0.8-μm CCTO thin film that was deposited at RT for 2 h and then annealed at 700°C in O2 exhibited a high dielectric constant (ε′) of 410, a dielectric loss (tan δ) of 0.17 (at 10 kHz), and a leakage current density (J) of 1.28 × 10−5 A/cm2 (at 25 kV/cm). 相似文献
11.
L. P. Kazakova K. D. Tsendin E. A. Lebedev D. Arsova I. A. Obukhova 《Semiconductors》2010,44(1):76-78
Charge-carrier transport in Ge20As20S60 films has been studied using the transit time method under low-injection conditions at room temperature. It was found that
drift mobilities of electrons and holes in Ge20As20S60 films are close to each other, i.e., μ
e
≈ μ
h
≈ 2 × 10−3 cm2 V−1 s−1 at T = 295 K and F = 5 × 104 V/cm. It was shown that the time dependence of the photocurrent during carrier drift and the voltage dependence of the drift
mobility allowed the use of the concept of anomalous dispersive transport. Experimental data were explained using the model
of transport controlled by carrier trapping by localized states with energy distribution near conduction and valence band
edges described by the exponential law with a characteristic energy of ∼0.05 eV. 相似文献
12.
The Seebeck coefficient, electrical resistivity, and thermal conductivity of Zr3Mn4Si6 and TiMnSi2 were studied. The crystal lattices of these compounds contain relatively large open spaces, and, therefore, they have fairly
low thermal conductivities (8.26 Wm−1 K−1 and 6.63 Wm−1 K−1, respectively) at room temperature. Their dimensionless figures of merit ZT were found to be 1.92 × 10−3 (at 1200 K) and 2.76 × 10−3 (at 900 K), respectively. The good electrical conductivities and low Seebeck coefficients might possibly be due to the fact
that the distance between silicon atoms in these compounds is shorter than that in pure semiconductive silicon. 相似文献
13.
Andrew Taylor Clay Mortensen Raimar Rostek Ngoc Nguyen David C. Johnson 《Journal of Electronic Materials》2010,39(9):1981-1986
This article demonstrates that carrier concentrations in bismuth telluride films can be controlled through annealing in controlled
vapor pressures of tellurium. For the bismuth telluride source with a small excess of tellurium, all the films reached a steady
state carrier concentration of 4 × 1019 carriers/cm3 with Seebeck coefficients of −170 μV K−1. For temperatures below 300°C and for film thicknesses of 0.4 μm or less, the rate-limiting step in reaching a steady state for the carrier concentration appeared to be the mass transport
of tellurium through the gas phase. At higher temperatures, with the resulting higher pressures of tellurium or for thicker
films, it was expected that mass transport through the solid would become rate limiting. The mobility also changed with annealing,
but at a rate different from that of the carrier concentration, perhaps as a consequence of the non-equilibrium concentration
of defects trapped in the films studied by the low temperature synthesis approach. 相似文献
14.
S. Ceresara M. Codecasa F. Passaretti P. Tomeš A. Weidenkaff C. Fanciulli 《Journal of Electronic Materials》2011,40(5):557-560
A Bi-15 at.%Sb alloy, homogenized by equal channel angular extrusion (ECAE) at T = 523 K, has been treated just above its solidus temperature, causing segregation of a secondary Bi-rich phase at the grain
boundaries. This process results in an in situ composite. The thermoelectric properties of the composite have been measured in the range of 5 K < T < 300 K. The results are compared with those of the homogeneous alloy. The presence of a Bi-rich phase improves the Seebeck
coefficient at T < 50 K, and enhances the electrical conductivity by a factor of 1.4 at T = 300 K up to a factor of 3.4 at T = 50 K; unfortunately, the thermal conductivity also increases by about 50% in the same temperature range. As a result, the
figure of merit, Z, is slightly suppressed above T = 110 K, but increases at lower temperatures, reaching a peak value of 4.2 × 10−3 K−1 at T = 90 K. The power factor considerably increases over the whole temperature range, rendering this material suitable as the
n-type leg of a cryogenic thermoelectric generator for cold energy recovery in a liquefied natural gas plant. 相似文献
15.
In this paper, a novel and simple sodium alginate (SA) gel method was developed to prepare γ-Na
x
Co2O4. This method involved the chemical gelling of SA in the presence of Co2+ ions by cross-linking. After calcining at 700°C to 800°C, single-phase γ-Na
x
Co2O4 crystals were obtained. The arrangement of about 1 μm to 4 μm flaky particles exhibited a well-tiled structure along the plane direction of the flaky particles. SA not only acted as
the control agent for crystal growth, but also provided a Na source for the γ-Na
x
Co2O4 crystals. The electrical properties of γ-Na
x
Co2O4 ceramics prepared via ordinary sintering after cold isostatic pressing were investigated. The Seebeck coefficient and power
factor of the bulk material were 177 μV K−1 and 4.3 × 10−4 W m−1 K−2 at 850 K, respectively. 相似文献
16.
Te-doped Mg2Si (Mg2Si:Te
m
, m = 0, 0.01, 0.02, 0.03, 0.05) alloys were synthesized by a solid-state reaction and mechanical alloying. The electronic transport
properties (Hall coefficient, carrier concentration, and mobility) and thermoelectric properties (Seebeck coefficient, electrical
conductivity, thermal conductivity, and figure of merit) were examined. Mg2Si was synthesized successfully by a solid-state reaction at 673 K for 6 h, and Te-doped Mg2Si powders were obtained by mechanical alloying for 24 h. The alloys were fully consolidated by hot-pressing at 1073 K for
1 h. All the Mg2Si:Te
m
samples showed n-type conduction, indicating that the electrical conduction is due mainly to electrons. The electrical conductivity increased
and the absolute value of the Seebeck coefficient decreased with increasing Te content, because Te doping increased the electron
concentration considerably from 1016 cm−3 to 1018 cm−3. The thermal conductivity did not change significantly on Te doping, due to the much larger contribution of lattice thermal
conductivity over the electronic thermal conductivity. Thermal conduction in Te-doped Mg2Si was due primarily to lattice vibrations (phonons). The thermoelectric figure of merit of intrinsic Mg2Si was improved by Te doping. 相似文献
17.
Alex Zevalkink Jessica Swallow G. Jeffrey Snyder 《Journal of Electronic Materials》2012,41(5):813-818
Ca5Al2Sb6 is a relatively inexpensive Zintl compound exhibiting promising thermoelectric efficiency at temperatures suitable for waste
heat recovery. Motivated by our previous studies of Ca5Al2Sb6 doped with Na and Zn, this study focuses on doping with Mn2+ at the Al3+ site. While Mn is a successful p-type dopant in Ca5Al2Sb6, we find that incomplete dopant activation yields lower hole concentrations than obtained with either previously investigated
dopant. High-temperature Hall effect and Seebeck coefficient measurements show a transition from nondegenerate to degenerate
semiconducting behavior in Ca5Al2−x
Mn
x
Sb6 samples (x = 0.05, 0.1, 0.2, 0.3, 0.4) with increasing Mn content. Ultimately, no improvement in zT is achieved via Mn doping, due in part to the limited carrier concentration range achieved. 相似文献
18.
Colby L. Heideman Raimar Rostek Michael D. Anderson Andrew A. Herzing Ian M. Anderson David C. Johnson 《Journal of Electronic Materials》2010,39(9):1476-1481
An ultralow-thermal-conductivity compound with the ideal formula [(PbSe)1.00]1[MoSe2]1 has been successfully crystallized across a range of compositions. The lattice parameters varied from 1.246 nm to 1.275 nm,
and the quality of the observed 00ℓ diffraction patterns varied through the composition region where the structure crystallized. Measured resistivity values
ranged over an order of magnitude, from 0.03 Ω m to 0.65 Ω m, and Seebeck coefficients ranged from −181 μV K−1 to 91 μV K−1 in the samples after the initial annealing to form the basic structure. Annealing of samples under a controlled atmosphere
of selenium resulted in low conductivities and large negative Seebeck coefficients, suggesting an n-doped semiconductor. Scanning transmission electron microscopy cross-sections confirmed the interleaving of bilayers of PbSe
with Se-Mo-Se trilayers. High-angle annular dark-field images revealed an interesting volume defect, where PbSe grew through
a region where a layer of MoSe2 would be expected in the perfect structure. Further studies are required to correlate the density of these defects with the
observed electrical properties. 相似文献
19.
Thermoelectric Properties of <Emphasis Type="Italic">n</Emphasis>-Type Multiple-Filled Skutterudites
Filled skutterudites are prospective intermediate temperature materials for␣thermoelectric power generation. CoSb3-based n-type filled skutterudites have good electrical transport properties with power factor values over 40 μW/cm K2 at elevated temperatures. Filling multiple fillers into the crystallographic voids of skutterudites would help scatter a
broad range of lattice phonons, thus resulting in lower lattice thermal conductivity values. We report the thermoelectric
properties of n-type multiple-filled skutterudites between 5 K and 800 K. The combination of different fillers inside the voids of the skutterudite
structure shows enhanced phonon scattering, and consequently a strong suppression of the lattice thermal conductivity. Very
good power factor values are achieved in multiple-filled skutterudite compared with single-element-filled materials. The dimensionless
thermoelectric figure of merit for n-type filled skutterudites is improved through multiple-filling in a wide temperature range. 相似文献
20.
Jae-Hong Lim Mi Yeong Park Dong Chan Lim Bongyoung Yoo Jung-Ho Lee Nosang V. Myung Kyu Hwan Lee 《Journal of Electronic Materials》2011,40(5):1321-1325
Thermoelectric Sb
x
Te
y
films were potentiostatically electrodeposited in aqueous nitric acid electrolyte solutions containing different concentrations
of TeO2. Stoichiometric Sb
x
Te
y
films were obtained by applying a voltage of −0.15 V versus saturated calomel electrode (SCE) using a solution consisting
of 2.4 mM TeO2, 0.8 mM Sb2O3, 33 mM tartaric acid, and 1 M HNO3. The nearly stoichiometric Sb2Te3 films had a rhombohedral structure, R[`3]m R\bar{3}m , with a preferred orientation along the (015) direction. The films had hole concentration of 5.8 × 1018/cm3 and exhibited mobility of 54.8 cm2/Vs. A more negative potential resulted in higher Sb content in the deposited Sb
x
Te
y
films. Furthermore, it was observed that the hole concentration and mobility decreased with increasingly negative deposition
potential, and eventually showed insulating properties, possibly due to increased defect formation. The absolute value of
the Seebeck coefficient of the as-deposited Sb2Te3 thin film at room temperature was 118 μV/K. 相似文献