68 research outputs found
Pengaruh Variasi Temperatur Uji ZEM-3 pada Properti Termoelektrik Lapisan Tipis Ti-doped ZnO
Lapisan tipis Ti-doped ZnO berhasil difabrikasi pada substrat kaca SiO2 dengan menggunakan metode DC Magnetron Sputtering. Proses sputtering dilakukan dalam waktu 30 menit dan dengan tegangan sebesar 339-349 Volt. Lapisan tipis yang terbentuk memiliki ketebalan 241.287 nm. Uji properti termoelektrik dilakukan pada temperatur 310 K, 373 K, 423 K, 473 K, 523 K, 573 K, dan 623 K. Hasilnya, nilai resistivitas listrik lapisan tipis menurun hingga 523 K, dengan nilai resistivitas terendahnya adalah 0.446 Ļ (mā¦ m). Nilai koefisien Seebeck yang dihasilkan adalah minus menandakan bahwa lapisan tipis merupakan semikonduktor tipe n. Nilai koefisien Seebeck selalu meningkat seiring dengan pertambahan temperatur. Semakin tinggi temperatur yang diberlakukan pada material semikonduktor, maka makin tinggi pula faktor dayanya. Faktor daya paling tinggi terjadi pada temperatur 573 K dengan 32 ĀµWm-1K2
Penggunaan Metode DC Magnetron Sputtering dalam Pembuatan Lapisan Tipis Tipe N (AZO) Sebagai Modul Termoelektrik
Penelitian mengenai termoelektrik sedang gencar dikembangkan sejak tahun 1990. Pada tahun 2017, mulai dikembangkan termoelektrik yang menggunakan lapisan tipis. Pada penelitian ini, dilakukan fabrikasi termoelektrik lapisan tipis tipe N menggunakan material Zink Oxide (ZnO) di doping dengan Al2O3. Massa ZnO yang diperlukan sebanyak 20.680 gram dan Al2O3 10.079 gram. Proses fabrikasi lapisan tipis dilakukan menggunakan mesin DC Magnetron Sputtering. Tahapan-tahapan dalam melakukan penelitian ini terbagi ke dalam tiga tahapan utama yakni sintesis, fabrikasi (sputtering), dan pengujian. Proses sputtering dilakukan selama 10 menit dan substrat yang digunakan yakni kaca. Pengujian yang dilakukan yakni pengujian ketebalan menggunakan Tolansky Apparatus, pngujian XRD untuk mengetahui fasa yang terbentuk, pengujian ZEM-3 untuk mengetahui resistivitas, Koefisien Seebeck, dan power factor. Berdasarkan pengujian yang dilakukan, diperoleh ketebalan dari lapisan tipis yang terbentuk yakni 74.72 nm. Nilai Koefisien Seebeck dari lapisan tipis yang terbentuk semakin bertambah seiring kenaikan suhu sehingga dapat disimpulkan bahwa material AZO baik digunakan untuk aplikasi termoelektrik pada rentang suhu 200-350 Ā°C
Selecting the suitable dopants: electronic structures of transition metal and rare earth doped thermoelectric sodium cobaltate
Engineered is considered a prime candidate to achieve
high-efficiency thermoelectric systems to regenerate electricity from waste
heat. In this work, three elements with outmost electronic configurations, (1)
an open d shell (Ni), (2) a closed d shell (Zn), and (3) a half filled f shell
(Eu) with maximum unpaired electrons, were selected to outline the dopants'
effects on electronic and crystallographic structures of .
Systematic density functional calculations with package
showed that the Ni and Zn were more stable when substituting Co with formation
energy eV, eV when Fermi level equals to the valence band
maximum. While Eu is more stable when it substitutes Na having formation energy
of eV. As these results show great harmony with existing experimental
data, they provide new insights into the fundamental principle of dopant
selection for manipulating the physical properties in the development of
high-performance sodium cobaltate based multifunctional materials.Comment: 8 pages, 9 figure
Fabrication of p-type (MCCO) thin film using DC magnetron sputtering as a preparator for thermoelectric module
Based on existing research, thermoelectric efficiency can be improved through material selection. In this study, the material used is CaCOā doped with Mn and CoāOā to form CaCo3.5Mn0.5O9 material as a p-type thermoelectric material. The substrate used is glass. The stages in this research are material synthesis, sputtering process using DC Magnetron Sputtering machine to form thin films, and testing. The synthesis process includes grinding, calcination, and sintering. Grinding is done using a Ball Mill machine with a rotation speed of 250 rpm for 5 hours. Furthermore, the calcination step was carried out by heating the sample into a furnace at a temperature of 800Ā°C for 10 hours. Then the sintering process was carried out at a temperature of 850Ā°C for 12 hours. After the synthesis process is complete, enter the sputtering process using a DC Magnetron Sputtering machine for approximately 10 minutes. The gas used in this research is Argon (Ar). After the sputtering process was carried out, several tests appeared, such as the XRD test to determine the type of crystal, the ZEM-3 test to determine the Seebeck coefficient and resistivity, the thickness of the thin film formed, and the power factor test to determine the maximum voltage and power generated by the module formed. Several power factor test results were obtained, consisting of 107 Ī¼W/mKĀ² at 100Ā°C, 108 Ī¼W/mKĀ² at 200Ā°C, and 332 Ī¼W/mKĀ² at 300Ā°C and a thickness of 90.34 nm
Characterization of electron and phonon transports in Bi-doped CaMnO3 for thermoelectric applications
Electron and phonon transports in CaMnO3 and its Bi-doped counterpart,
Bi0.03Ca0.97MnO3, are investigated by thermoelectric transport measurements,
Raman spectroscopy, and first-principles calculations. In particular, we focus
on CaMnO3 and Bi0.03Ca0.97MnO3's electronic structures, temperature-dependent
electron and phonon lifetimes, and their sound velocities. We find that the
anti-ferromagnetic insulator CaMnO3 breaks the Wiedemann-Franz (WF) law with
the Lorenz number reaching four times that of ordinary metals at room
temperature. Bismuth doping reduces both the electrical resistivity and the
Seebeck coefficient of CaMnO3, thus it recovers the WF law behavior. Raman
spectroscopy confirms that Bi0.03Ca0.97MnO3 has a lower Debye frequency as well
as a shorter phonon lifetime. As a result, Bi0.03Ca0.97MnO3 exhibits superior
thermoelectric properties over the pristine CaMnO3 due to the lower thermal
conductivity and electronic resistivity.Comment: 7 pages, 7 figure
The Role of Sodium-Rich Pretreatments in the Enhanced Sintering of Sodium Cobalt Oxide Thermoelectric Ceramics
Theoretical Simulation of Thermoelectric Generator consisting of n-Mg2Si and p-MnSi1.75 by Finite Element Method
Design and Implementation of a Low Cost DAQ System for Thermoelectric Property Measurements
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