scholarly journals Annealing Effect on Seebeck Coefficient of SiGe Thin Films Deposited on Quartz Substrate

Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1435
Author(s):  
Kaneez Fatima ◽  
Hadia Noor ◽  
Adnan Ali ◽  
Eduard Monakhov ◽  
Muhammad Asghar

Over the past few years, thermoelectrics have gained interest with regard to thermoelectricity interconversion. The improvement in the efficiency of the thermoelectric material at an ambient temperature is the main problem of research. In this work, silicon–germanium (SiGe) thin films, owing to superior properties such as nontoxicity, high stability, and their integrability with silicon technologies, were studied for thermoelectric applications. P-type SiGe thin films were deposited on quartz substrates by DC/RF magnetron sputtering and annealed at three different temperatures for 1 hour. Significant enhancement in the Seebeck coefficient was achieved for the sample annealed at 670 °C. A high power factor of 4.1 μWcm−1K−2 was obtained at room temperature.

2013 ◽  
Vol 200 ◽  
pp. 14-21 ◽  
Author(s):  
Waclaw Bala ◽  
Yurij Zorenko ◽  
Volodymyr Savchyn ◽  
Taras Voznyak ◽  
Kazimierz Paprocki ◽  
...  

The ZnO thin films have been produced on p-type Si and quartz substrates by the spin-coating method and after deposition were heated at different temperatures in the range from 650K to 850K. The photoluminescence (PL) and cathodoluminescence (CL) measurements were carried out at temperature range 12K-350K. I-V, C-V measurements were performed on the Al/ZnO/Si/Al structures at different temperatures. The structural properties of the ZnO thin films were carried out using x-ray and SEM method. The effects of the thickness variation and annealing temperature on the crystallinity parameters were observed. The electrical response of grains, grain boundaries, and contacts of the ZnO film was obtained.


2018 ◽  
Vol 32 (31) ◽  
pp. 1850379
Author(s):  
Yiqi Li ◽  
Lian Chen ◽  
Quanrong Deng ◽  
Yonglong Shen ◽  
Geming Wang ◽  
...  

Delafossite CuFeO[Formula: see text] thin films were fabricated on quartz substrate using radio-frequency sputtering deposition under low O2 flow ratios from 9% to 0% at room temperature. The as-deposited films were in amorphous phase and crystallized into rhombohedral 3R (R3m) delafossite structure after post annealing at 900[Formula: see text]C for 2 h in flowing N2 atmosphere. SEM images showed that the films were composed of nano-sized crystallized grains, thin film composed of smoother surface and higher oxygen content was obtained under higher oxygen percentage in sputtering gas. The optical transmission spectra of these films were studied in the wavelength range 200–1500 nm and the results revealed a narrowing trend of direct bandgap from 3.09 eV to 2.98 eV with the decrease of oxygen flow ratio during deposition. All of the post-annealed CuFeO[Formula: see text] thin films exhibited p-type conductivity and linear ohmic contact feature with Cu electrodes. The carrier concentration of thin films increased from [Formula: see text] to [Formula: see text] whereas the carrier mobility decreased from [Formula: see text] to [Formula: see text] as the oxygen flow ratio reduced from 9% to 0%. The ability of controlling compound composition enables tuning of carrier concentration and mobility in CuFeO[Formula: see text] and offering essential technical basis in engineering photoelectronic devices.


2018 ◽  
Vol 7 (4.30) ◽  
pp. 213
Author(s):  
Lam Wai Yip ◽  
Afishah Alias ◽  
Asmahani Binti Awang ◽  
Abu Bakar Bin Abd Rahman ◽  
Khairul Anuar Bin Mohamad ◽  
...  

Cu-based conductive oxide such as CuGaO2 is seen to be a promising transparent p-type oxide material. The study of p-type semiconductor CuGaO2 thin films have been carried out to investigate the effects of different parameters in providing the optimum result in achieving good optical transparency and conductivity of the thin film. The CuGaO2 thin films were fabricated on quartz substrate via the Radio Frequency (RF) magnetron sputtering technique with varying substrate temperatures and different annealing temperatures. The p-type thin films were deposited at a temperature ranging from room temperature, 100°C, 200°C and 300°C. The samples were also annealed varying from temperature of 500°C, 600°C, 700°C and 800°C. The fabricated sample were characterized using X-ray diffraction (XRD), UV-Visible spectroscopy, and atomic force microscope (afm). XRD showed a peak at 2θ = 36.10° (012). The optical transparency values achieved from UV-Vis spectrometer were seen to be approximately 80% and the bandgaps were found to be in the range of 3.34-3.43 eV which is in line with the bandgap value from the research on CuGaO2 thin films.  From the afm, the mean surface roughness increases with increasing temperature and this is due to the increment of grain size. The highest grain size was observed at substrate temperature of 200°C.


2015 ◽  
Vol 1792 ◽  
Author(s):  
Jiantuo Gan ◽  
Augustinas Galeckas ◽  
Vishnukanthan Venkatachalapathy ◽  
Heine N. Riise ◽  
Bengt G. Svensson ◽  
...  

ABSTRACTCuxO thin films have been deposited on a quartz substrate by reactive radio frequency (rf) magnetron sputtering at different target powers Pt (140-190 W) while keeping other growth process parameters fixed. Room-temperature photoluminescence (PL) measurements indicate considerable improvement of crystallinity for the films deposited at Pt>170 W, with most pronounced excitonic features being observed in the film grown using Pt=190 W. These results corroborate well with the surface morphology of the films, which was found more flat, smooth and homogeneous for Pt >170 W films in comparison with those deposited at lower powers.


Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1183
Author(s):  
Peiyu Wang ◽  
Xin Wang ◽  
Fengyin Tan ◽  
Ronghua Zhang

Molybdenum disulfide (MoS2) thin films were deposited at different temperatures (150 °C, 225 °C, 300 °C, 375 °C, and 450 °C) on quartz glass substrates and silicon substrates using the RF magnetron sputtering method. The influence of deposition temperature on the structural, optical, electrical properties and deposition rate of the obtained thin films was investigated by X-ray diffraction (XRD), Energy Dispersive Spectrometer (EDS), Raman, absorption and transmission spectroscopies, a resistivity-measuring instrument with the four-probe method, and a step profiler. It was found that the MoS2 thin films deposited at the temperatures of 150 °C, 225 °C, and 300 °C were of polycrystalline with a (101) preferred orientation. With increasing deposition temperatures from 150 °C to 300 °C, the crystallization quality of the MoS2 thin films was improved, the Raman vibrational modes were strengthened, the deposition rate decreased, and the optical transmission and bandgap increased. When the deposition temperature increased to above 375 °C, the molecular atoms were partially combined with oxygen atoms to form MoO3 thin film, which caused significant changes in the structural, optical, and electrical properties of the obtained thin films. Therefore, it was necessary to control the deposition temperature and reduce the contamination of oxygen atoms throughout the magnetron sputtering process.


2010 ◽  
Vol 1245 ◽  
Author(s):  
Reza Anvari ◽  
Qi Cheng ◽  
Muhammad Lutful Hai ◽  
Truc Phan Bui ◽  
A. J. Syllaios ◽  
...  

AbstractThis paper presents the formation and the characterization of silicon germanium oxide (SixGeyO1-x-y) infrared sensitive material for uncooled microbolometers. RF magnetron sputtering was used to simultaneously deposit Si and Ge thin films in an Ar/O2 environment at room temperature. The effects of varying Si and O composition on the thin film's electrical properties which include temperature coefficient of resistance (TCR) and resistivity were investigated. The highest achieved TCR and the corresponding resistivity at room temperature were -5.41 %/K and 3.16×103 ohm cm using Si0.039Ge0.875O0.086 for films deposited at room temperature.


2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Pornsiri Wanarattikan ◽  
Piya Jitthammapirom ◽  
Rachsak Sakdanuphab ◽  
Aparporn Sakulkalavek

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.


2016 ◽  
Vol 113 (48) ◽  
pp. 13576-13581 ◽  
Author(s):  
Ran He ◽  
Daniel Kraemer ◽  
Jun Mao ◽  
Lingping Zeng ◽  
Qing Jie ◽  
...  

Improvements in thermoelectric material performance over the past two decades have largely been based on decreasing the phonon thermal conductivity. Enhancing the power factor has been less successful in comparison. In this work, a peak power factor of ∼106 μW⋅cm−1⋅K−2is achieved by increasing the hot pressing temperature up to 1,373 K in the p-type half-Heusler Nb0.95Ti0.05FeSb. The high power factor subsequently yields a record output power density of ∼22 W⋅cm−2based on a single-leg device operating at between 293 K and 868 K. Such a high-output power density can be beneficial for large-scale power generation applications.


2018 ◽  
Vol 24 (8) ◽  
pp. 5866-5871 ◽  
Author(s):  
G Balakrishnan ◽  
J. S. Ram Vinoba ◽  
R Rishaban ◽  
S Nathiya ◽  
O. S. Nirmal Ghosh

Nickel oxide (NiO) thin films were deposited on glass substrates using the RF magnetron sputtering technique at room temperature. The Argon and oxygen flow rates were kept constant at 10 sccm and 5 sccm respectively. The films were annealed at various temperatures (RT-300 °C) and its influence on the microstructural, optical and electrical properties were investigated. The X-ray diffraction (XRD) investigation of NiO films indicated the polycrystallinity of the films with the (111), (200) and (220) reflections corresponding to the cubic structure of NiO films. The crystallite size of NiO films was in the range ~4–14 nm. The transmittance of the films increased from 20 to 75% with increasing annealed temperature. The optical band gap of the films was 3.6–3.75 eV range for the as-deposited and annealed films. The Hall effect studies indicated the p-type conductivity of films and the film annealed at 300 °C showed higher carrier concentration (N), high conductivity (σ) and high mobility (μ) compared to other films. These NiO films can be used as a P-type semiconductor material in the devices require transparent conducting films.


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