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 ρ (mΩ 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 µWm-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 °C

Fabrication and Performance Analysis of AZO and MCCO as Thin Film-Thermoelectric Generator Materials

The purpose of this research was to determine the performance of AZO and MCCO materials as constituents of the thin film-thermoelectric generator module. The method used for fabrication is DC Magnetron Sputtering. The electrode material used is Ag and the substrate used is SiO2 glass. The arrangement of the thin film used for the fabrication of the thermoelectric module is P-N-P-N-P-N-P-N-P-N (5 couples of p-n junctions). Based on the test results, the thickness of the thin film type N is 74.72 nm and type P is 90.34 nm. At the highest test temperature (300 oC), the AZO Seebeck coefficient value is -108 µV/K while the MCCO Seebeck coefficient value is 350 µV/K, and the AZO electrical resistivity value is 0.07 Ω.m while the MCCO electrical resistivity value is 0.36 Ω.m. The highest temperature difference given in the test of the AZO and MCCO thin film thermoelectric module is 1.538 °C and the thermoelectric module can produce a voltage of 1,842 ± 0.047 mV, a Seebeck coefficient of 4 µV/K, and an efficiency of 0.44%. Based on this research, it can be concluded that the performance of AZO and MCCO thin film-thermoelectric modules will have better performance at temperatures around 300 - 350 °C

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 CaCO₃ doped with Mn and Co₂O₃ 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 800°C for 10 hours. Then the sintering process was carried out at a temperature of 850°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 μW/mK² at 100°C, 108 μW/mK² at 200°C, and 332 μW/mK² at 300°C and a thickness of 90.34 nm

Investigation on the Enhancement of the Thermoelectric Power Factor of ZnO Thin Films by Al-doping using Asymmetric Bipolar Pulsed-DC Magnetron Sputtering Technology

AbstractZnO and Al-doped ZnO thin films were deposited on ceramic substrate by using an asymmetric bipolar pulsed-DC magnetron sputtering system under Ar atmosphere. Compacted ZnO powder and ZnO:Al2O3 premixed powder in copper supports were used as sputtering targets for the deposition of ZnO and Al-doped ZnO thin films, respectively. Optical emissions from the plasma during the deposition, measured using a high resolution spectrometer in the wavelength range of 360-800 nm, showed that the constituents of each target were successfully sputtered off. X-ray diffraction (XRD) analysis confirmed the formation of ZnO and Al-doped ZnO thin films of hexagonal crystal structure. The deposition rates of 24 and 15 nm/min were obtained for the ZnO and Al-dopoed ZnO thin films, respectively. The electrical conductivity and Seebeck coefficient of the thin films were measured at room temperature by the steady state and the Van der Pauw four probe methods, respectively. The increase in thermoelectric power factor of about 2 orders of magnitude was observed for the Al-doped ZnO thin films

Thermoelectric Power Factor Enhancement by Pulsed Plasma Engineering in Magnetron Sputtering Induced Ge₂Sb₂Te₅ Thin Films

Precise control over microstructure and composition is desired prerequisite for the performance enhancement of thermoelectric materials. In conventional magnetron plasma sputtering synthesis, composition control is challenging when the sputtering-target is composed by different elements. Here, the potential of pulsed power utilization is demonstrated for compositional control of Ge₂Sb₂Te₅ thin films via pulse-reversal time and pulse-frequency engineering in pulsed DC-magnetron sputtering process. When annealed at 400 °C for 1 h in vacuum conditions, amorphous thin films (of 200 nm thickness, deposited on glass substrate) crystallize in to face centered cubic phase with average nanocrystallite size ∼10 nm. Power density enhancement to 5.56 W/cm² at low pulse reversal time induces maximum process throughput as 450 nm/min. Increase in either of pulse frequency or pulse reversal time decreases the discharge voltage and plasma density. As a consequence, kinetic energy of ions and ionization of plasma species are sequentially controlled to improve the stoichiometry of film and eventually; the electronic transport. The optimization of pulse plasma engineering yields maximum thermoelectric power factor value as 1.35 μW cm^–1 K^–2 with process throughput more than 300 nm/min. The obtained values are promising for applications in the automobile and microelectronics industry