scholarly journals Effect of Surfactant Concentration Variation on the Thermoelectric Properties of Mesoporous ZnO

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Min-Hee Hong ◽  
Chang-Sun Park ◽  
Sangwoo Shin ◽  
Hyung Hee Cho ◽  
Won-Seon Seo ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Surfactant Concentration ◽  
Zinc Acetate Dihydrate ◽  
Zno Thin Films ◽  
Molar Ratio ◽  
Zno Films ◽  
Mesoporous Zno

The electrical and thermal conductivities and the Seebeck coefficient of mesoporous ZnO thin films were investigated to determine the change of their thermoelectric properties by controlling surfactant concentration in the mesoporous ZnO films, because the thermoelectric properties of mesoporous ZnO films can be influenced by the porosity of the mesoporous structures, which is primarily determined by surfactant concentration in the films. Mesoporous ZnO thin films were successfully synthesized by using sol-gel and evaporation-induced self-assembly processes. Zinc acetate dihydrate and Brij-76 were used as the starting material and pore structure-forming template, respectively. The porosity of mesoporous ZnO thin films increased from 29% to 40% with increasing surfactant molar ratio. Porosity can be easily altered by controlling the molar ratio of surfactant/precursor. The electrical and thermal conductivity and Seebeck coefficients showed a close correlation with the porosity of the films, indicating that the thermoelectric properties of thin films can be changed by altering their porosity. Mesoporous ZnO thin films with the highest porosity had the best thermoelectric properties (the lowest thermal conductivity and the highest Seebeck coefficient) of the films examined.

scholarly journals Effect of Grain Size and Film Thickness on the Thermoelectric Properties of Flexible Sb2Te3 Thin Films

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Pornsiri Wanarattikan ◽  
Piya Jitthammapirom ◽  
Rachsak Sakdanuphab ◽  
Aparporn Sakulkalavek
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Grain Size ◽  
Film Thickness ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Flexible Substrate ◽  
Rf Magnetron Sputtering ◽  
Mean Free Path

In this work, stoichiometric Sb2Te3 thin films with various thicknesses were deposited on a flexible substrate using RF magnetron sputtering. The grain size and thickness effects on the thermoelectric properties, such as the Seebeck coefficient (S), electrical conductivity (σ), power factor (PF), and thermal conductivity (k), were investigated. The results show that the grain size was directly related to film thickness. As the film thickness increased, the grain size also increased. The Seebeck coefficient and electrical conductivity corresponded to the grain size of the films. The mean free path of carriers increases as the grain size increases, resulting in a decrease in the Seebeck coefficient and increase in electrical conductivity. Electrical conductivity strongly affects the temperature dependence of PF which results in the highest value of 7.5 × 10−4 W/m·K2 at 250°C for film thickness thicker than 1 µm. In the thermal conductivity mechanism, film thickness affects the dominance of phonons or carriers. For film thicknesses less than 1 µm, the behaviour of the phonons is dominant, while both are dominant for film thicknesses greater than 1 µm. Control of the grain size and film thickness is thus critical for controlling the performance of Sb2Te3 thin films.

Photocatalytic Properties of ZnO and Ag Doped ZnO Thin Films

2014 ◽  
Vol 685 ◽  
pp. 3-6
Author(s):  
Ying Lian Wang ◽  
Jun Yao Ye
Keyword(s):  
Thin Films ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Structural Features ◽  
Photocatalytic Properties ◽  
Zno Thin Films ◽  
Molar Ratio ◽  
Zno Films ◽  
Doped Zno ◽  
Excellent Adhesion

Pure ZnO thin films and Ag doped ZnO thin films were prepared on quartz substrates by sol-gel process. Structural features and UV absorption spectrum have been studied by XRD and UV-Vis-Nir scanning spectrophotometer. Taking phenol as pollutants, further study of the effect of different annealing temperature and Ag dopant amount of ZnO films on photocatalytic properties was carried out. The results showed that, the optimal annealing temperature on photocatalytic degradation of phenol in this experiment was 300 °C, the best molar ratio of ZnO and Ag was 30:1, which was better than pure ZnO film greatly. Excellent adhesion, recyclable and efficient degradation Ag doped ZnO thin films were found in this experiment.

Thermoelectric Properties of YbBiPt and YBiPt Thin Films

2008 ◽  
Vol 1100 ◽  
Author(s):  
Sadik Guner ◽  
Satilmis Budak ◽  
Claudiu I Muntele ◽  
Daryush Ila
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Rutherford Backscattering Spectrometry ◽  
Conductivity Measurement ◽  
Electronic Energy ◽  
Before And After

AbstractMonolayer thin films of YbBiPt and YBiPt have been produced with 560 nm and 394 nm thick respectively in house and their thermoelectric properties were measured before and after MeV ion bombardment. The energy of the ions were selected such that the bombarding Si ions stop in the silicon substrate and deposit only electronic energy by ionization in the deposited thin film. The bombardment by 5.0 MeV Si ions at various fluences changed the homogeneity as well as reducing the internal stress in the films thus affecting the thermal, electrical and Seebeck coefficient of thin films. The stoichiometry of the thin films was determined using Rutherford Backscattering Spectrometry, the thickness has been measured using interferometry and the electrical conductivity was measured using Van der Pauw method. Thermal conductivity of the thin films was measured using an in-house built 3ω thermal conductivity measurement system. Using the measured Seebeck coefficient, thermal conductivity and electrical conductivity we calculated the figure of merit (ZT). We will report our findings of change in the measured figure of merit as a function of bombardment fluence.

Effect of TiO2 additive on thermoelectric properties of SrTiO3

2019 ◽  
Vol 13 (02) ◽  
pp. 2051001
Author(s):  
Wei-Ying Yang ◽  
Ke-Xian Wang ◽  
Zheng Cao ◽  
Hao-Yang Yu ◽  
Xiao-Bo Ma ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
High Temperature ◽  
Seebeck Coefficient ◽  
Strontium Titanate ◽  
Thermoelectric Properties ◽  
Waste Heat ◽  
Molar Ratio ◽  
Composite Powders ◽  
The Impact

Strontium titanate ([Formula: see text] has the advantages of being non-toxic, environmentally friendly and high-temperature stable, and has potential application in waste heat power generation at medium and high temperature. To explore the impact of TiO2 on the thermoelectric properties of SrTiO3, we synthesized TiO2/La10Nbb10-STO composite powders by hydrothermal method using precursor solution of 10[Formula: see text]mol.% La and 10[Formula: see text]mol.% Nb co-doped STO (La10Nb10-STO) containing TiO2 nanopowders with different molar ratio. After cold pressing and sintering, composite bulk materials were obtained, and their microstructure and thermoelectric transport properties were analyzed. With the increasing TiO2, although the thermal conductivity of TiO2/La10Nb10-STO composite decreased and the Seebeck coefficient increased, the minimum thermal conductivity and the maximum Seebeck coefficient were 2.54[Formula: see text][Formula: see text][Formula: see text] and 215[Formula: see text][Formula: see text]V[Formula: see text][Formula: see text], respectively, at 1000[Formula: see text]K, but the power factor decreased at high temperature due to the apparent decrease of electrical conductivity, resulting in the ZT values being lower than that of La0Nb10-STO without TiO2 addition at high temperature. Significantly, the addition of TiO2 can improve the thermoelectric performance of strontium titanate at low temperature. This approach is expected to improve the ZT of SrTiO3-based thermoelectric material through additional controlling of electrical conductivity.

Effect of mesopore-induced strain/stress on the thermoelectric properties of mesoporous ZnO thin films

2018 ◽  
Vol 446 ◽  
pp. 160-167 ◽  
Author(s):  
Min-Hee Hong ◽  
Dong Il Shim ◽  
Hyung Hee Cho ◽  
Hyung-Ho Park
Keyword(s):  
Thin Films ◽  
Thermoelectric Properties ◽  
Zno Thin Films ◽  
Strain Stress ◽  
Mesoporous Zno

Growth and Characterisation of Nanocrystalline ZnO Thin Films by Dip Coating Technique

2013 ◽  
Vol 832 ◽  
pp. 368-373
Author(s):  
Mohd Firdaus Malek ◽  
Mohamad Hafiz Mamat ◽  
Mohd Zainizan Sahdan ◽  
Musa Mohamed Zaihidi ◽  
Zuraida Khusaimi ◽  
...  
Keyword(s):  
Thin Films ◽  
Zinc Acetate ◽  
Sol Gel ◽  
Homogeneous Solution ◽  
Nir Spectroscopy ◽  
Dip Coating ◽  
Zno Thin Films ◽  
Molar Ratio ◽  
Zno Films ◽  
Glass Substrates

Nanocrystalline zinc oxide (ZnO) thin films have been obtained by the sol gel process. A stable and homogeneous solution was prepared by dissolving zinc acetate dehydrate as a starting material in a solution of 2-methoxyethanol and monoethanolamine (MEA). The molar concentration of zinc acetate was fixed at 0.6 mol/L while the molar ratio of MEA to zinc acetate was kept at 1:1. The films were deposited by various deposition speeds by dip-coating on glass substrates, and subsequently transformed into nanocrystalline pure ZnO films after a thermal treatment. Various deposition speeds were selected as the parameter to optimize the thin films quality. The structural and optical properties of the ZnO films were studied by X-ray diffraction (XRD), UV-Vis-NIR spectroscopy, respectively. The electrical properties of the ZnO thin films were characterised by dc 2 probing system and power supply (Advantest R6243). It was found that the deposition speed affects the resultant properties of ZnO thin films.

Structural and optical properties of ZnO thin film prepared by sol-gel spin coating

2020 ◽  
Vol 38 (1) ◽  
pp. 17-22
Author(s):  
G Balakrishnan ◽  
Vivek Sinha ◽  
Yogesh Palai Peethala ◽  
Manoj Kumar ◽  
R.J. Golden Renjith Nimal ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Spin Coating ◽  
Zinc Acetate Dihydrate ◽  
Sol Gel ◽  
Hexagonal Structure ◽  
Zno Thin Films ◽  
Zno Films ◽  
Structural And Optical Properties ◽  
Vis Spectroscopy

AbstractZinc oxide (ZnO) thin films were deposited on Si (1 0 0) and glass substrates by sol-gel spin coating technique. Zinc acetate dihydrate, monoethanolamine and isopropanol were used as the sources for precursor solution and the resulting gel was used for the preparation of ZnO thin films. The films were annealed at different temperatures (100 °C to 500 °C) and the effect of annealing on the structural and optical properties was investigated. X-ray diffraction (XRD) and UV-Vis spectroscopy were used for the analysis of the films. The XRD results indicated the polycrystalline hexagonal structure of the ZnO films with (0 0 2) orientation. The optical properties of the films were studied using UV-Vis spectrophotometer in the wavelength range of 190 – 1100 nm. The optical characterization of the ZnO thin films showed the high transmittance of ~90 % for the films annealed at 400 °C. The films showed the absorbance ~360 – 390 nm and bandgap values of 3.40 – 3.10 eV, depending on the annealing temperature of the films.

Effects of the Sputtering Time of AlN Buffer Layer on the Quality of ZnO Thin Films

2014 ◽  
Vol 881-883 ◽  
pp. 1117-1121 ◽  
Author(s):  
Xiang Min Zhao
Keyword(s):  
Thin Films ◽  
Buffer Layer ◽  
Rf Magnetron Sputtering ◽  
Buffer Layers ◽  
Zno Thin Films ◽  
Zno Films ◽  
Si Substrates ◽  
Atomic Force ◽  
Structure Morphology ◽  
Aln Buffer

ZnO thin films with different thickness (the sputtering time of AlN buffer layers was 0 min, 30 min,60 min, and 90 min, respectively) were prepared on Si substrates using radio frequency (RF) magnetron sputtering system.X-ray diffraction (XRD), atomic force microscope (AFM), Hall measurements setup (Hall) were used to analyze the structure, morphology and electrical properties of ZnO films.The results show that growth are still preferred (002) orientation of ZnO thin films with different sputtering time of AlN buffer layer,and for the better growth of ZnO films, the optimal sputtering time is 60 min.

MeV Ion-Beam Bombardment Effects on The Thermoelectric Figures of Merit of Zn4Sb3 and ZrNiSn-Based half-heusler compounds

2007 ◽  
Vol 1020 ◽  
Author(s):  
S. Budak ◽  
S. Guner ◽  
C. Muntele ◽  
C. C. Smith ◽  
B. Zheng ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Seebeck Coefficient ◽  
Measurement System ◽  
Ion Beam ◽  
Electrical Energy ◽  
Figures Of Merit ◽  
Material Systems ◽  
The Cross ◽  
Conductivity Of Thin Films

AbstractSemiconducting â-Zn4Sb3and ZrNiSn-based half-heusler compound thin films were prepared by co-evaporation for the application of thermoelectric (TE) materials. High-purity solid zinc and antimony were evaporated by electron beam to grow the â-Zn4Sb3thin film while high-purity zirconium powder and nickel tin powders were evaporated by electron beam to grow the ZrNiSn-based half-heusler compound thin film. Rutherford backscattering spectrometry (RBS) was used to analyze the composition of the thin films. The grown thin films were subjected to 5 MeV Si ions bombardments for generation of nanostructures in the films. We measured the thermal conductivity, Seebeck coefficient, and electrical conductivity of these two systems before and after 5 MeV Si ions beam bombardments. The two material systems have been identified as promising TE materials for the application of thermal-to-electrical energy conversion, but the efficiency still limits their applications. The electronic energy deposited due to ionization in the track of MeV ion beam can cause localized crystallization. The nanostructures produced by MeV ion beam can cause significant change in both the electrical and the thermal conductivity of thin films, thereby improving the efficiency. We used the 3ù-method measurement system to measure the cross-plane thermal conductivity ,the Van der Pauw measurement system to measure the cross-plane electrical conductivity, and the Seebeck-coefficient measurement system to measure the cross-plane Seebeck coefficient. The thermoelectric figures of merit of the two material systems were then derived by calculations using the measurement results. The MeV ion-beam bombardment was found to decrease the thermal conductivity of thin films and increase the efficiency of thermal-to-electrical energy conversion.

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...

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