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The analysis of surface morphology, band gaps and optical properties of PAN/GO thin films

Matysiak W., Adamczyk K.

Archives of Materials Science and Engineering

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2020

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Vol. 101, nr 2

49--56

EN

Purpose: PAN/GO nanocomposites are gaining more and more interest from research and industrial environments. According to theoretical studies and experimental tests, PAN/ GO exhibits excellent properties such as tensile strength, good thermal and electrical conductivity, excellent thermal and tribological properties. Thanks to this property, the composite is considered the ideal successor to the nanocomposites used so far. The PAN/GO nanocomposite has great potential in the filtration, automotive, electrical and photovoltaic industry. Design/methodology/approach: The spin-coating process is used to produce thin layers by centrifuging a liquid substance on flat surfaces. The advantages of the spin- coating process are simplicity and ease with which the process can be carried out. Due to the ability to high spin speeds, high airflow leads to fast drying time, which in turn results in high consistency in both macroscopic and nanometre scales. The spin-coting method is usually the starting point and reference point for most academic and industrial processes that require a thin and uniform coating. The use of spin coating has a wide spectrum. This technique can be used to coat small substrates (from a few square mm) up to the coating of flat displays, e.g. TV sets, which may have a meter or more in diameter. Findings: Among the existing methods for producing thin layers, including physical and chemical methods for gas phase deposition or the self-assembly process, the spin-coating process makes it possible to produce uniform thin nanocomposite layers in an easy and cheap way. Spin coating is usually the starting point and reference point for most academic and industrial processes that require a thin and uniform coating. The advantage of the method is the wide spectrum of use. It is used for coating substrates with everything from photoresists, insulators, organic semiconductors, synthetic metals, nanomaterials, metal precursors and metal oxides, transparent conductive oxides and many other materials. Often, spin coating is used to unravel polymer layers or photoresist on semiconductor substrates. Research limitations/implications: Due to the ongoing research on the potential applications of PAN/GO thin layers, including electronics, automotive and photovoltaics, it is worth trying to optimize the parameters of the spin-coiling process such as rotational speed or duration of the process. It is also worth trying to optimize the concentration of GO in the nanocomposite. Practical implications: Despite mixing the solution with an ultrasonic homogenizer to disperse the nanoparticles, the particles dispersed to form a rough surface. Originality/value: Low-cost, easy to carry out method of producing thin nanocomposite layers, having significant application in laboratory environments.

2

Manufacturing process and optical properties of zinc oxide thin films as photoanode in DSSC

Matysiak W., Tański T., Zaborowska M.

Journal of Achievements in Materials and Manufacturing Engineering

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2018

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Vol. 86, nr 1

33--40

EN

Purpose: It has been recently observed, that zinc oxide thin films are gaining much popularity, particularly in applications such as toxic gas sensors, photocatalytic materials and photovoltaic cells. Due to much better physical properties of ZnO compared to the ones of titanium dioxide (TiO2), which is currently the most used material in dye sensitized solar cells, efforts are being made to fabricate DSSCs with thin films and/or nanostructures, including nanowires, nanofibres and nanoparticles of zinc oxide. Design/methodology/approach: In this paper, zinc oxide thin films were prepared using sol-gel and spin coating methods from Zn(COO)2 x 2H2O dissolved in ethanol and acetic acid with ZnO monocrystalline nanoparticles of 0 and 10% (wt.) relative to the final concentration of produced solutions. The effect of calcination process on ZnO thin films at 600°C were examined using atomic force microscope to investigate the morphology of semiconductor coatings, infrared spectroscopy to prove the chemical structure of material. Besides, optical properties were analysed on the basis of absorbance in the function of wavelength spectra and the values of energy band gaps were studied. Findings: The topography analysis of ZnO thin films showed an increase in roughness with the increase of zinc oxide nanoparticles in the thin films material. In addition, the analysis of the optical properties of ZnO thin films showed a decrease in absorption level in the range of near-ultraviolet wavelength for the obtained layers after annealing. Research limitations/implications: It was found that ZnO thin films produced by spin coating and calcination method are a proper material for photoanode in dye-sensitized solar cells, as zinc oxide layers provide better conductivity across the photovoltaic cell. Practical implications: The results provide the possibility of production DSSCs with zinc oxide thin films as photoanode. Originality/value: The dye-sensitized solar cells based on zinc oxide photoanodes could be alternative semiconductor material to titanium dioxide, which is used in nowadays solar cells. It was estimated that ZnO, especially zinc oxide nanostructures have much better physical properties, than TiO2 structures. What is more, zinc oxide thin layers are characterized by the lower energy losses resulting from the physical properties of such nanostructures, which results in more efficient solar energy into electricity conversion.

3

Optical properties of PVP/ZnO composite thin films

Tański T., Matysiak W.

Journal of Achievements in Materials and Manufacturing Engineering

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2017

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Vol. 82, nr 1

5--11

EN

Purpose: The aim of the work was the preparation of thin composite layers from PVP polymer doped by ZnO nanoparticles using the spin coating method and the analysis of the applied reinforcing phase on the morphology and optical properties of obtained composites. Design/methodology/approach: To analyse the morphology of thin coatings a technique of surface topography imaging using the atomic force microscopy (AFM) was applied. Analysis of the optical properties was conducted using absorbance spectrum in function of wavelength for all produced thin coatings using UV-Vis spectroscopy. Findings: AFM results show that mass concentration of ZnO nanoparticles of 10% in a solution of PVP/EtOH polymers has a meaningful influence on the morphology of the surface of the PVP/ZnO composite coatings. Using obtained absorbance spectra, the width of the band gap of the manufactured composite coatings were determined which were compared with a band gap values of pure polymer and used reinforcing phase. Practical implications: The analysis of the values of the energy band gap of the manufactured materials showed that both for pure polymer and composite coatings values of energy band gap are similar approx. 4 eV at the same time decrease the degree of absorption of electromagnetic radiation caused by the increasing concentration of the reinforcing phase, which indicates the broad possibilities of application of this type of the material.

4

Influence of solvent on the surface morphology and optoelectronic properties of a spin coated polymer thin films

Weszka J., Szindler M.M., Szczęsna M., Szindler M.

Journal of Achievements in Materials and Manufacturing Engineering

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2013

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Vol. 61, nr 2

302—307

EN

Purpose: The aim of this paper was to investigate changes in surface morphology and optoelectronic properties of MEH-PPV thin films. Thin films were prepared using spin coating method. Design/methodology/approach: The changes in surface topography was observed by the atomic force microscope AFM. The results of thin films roughness have been prepared in the software XEI. The UV/VIS spectrometer was used to investigate absorbance of the obtained thin films. Findings: Results and their analysis allow to conclude that the solvent, which is an important factor in spin coating technology has an influence on surface morphology and optoelectronic properties of MEH-PPV thin films. Practical implications: Known MEH-PPV optoeletronic properties and the possibility of obtaining a uniform thin film show that it can be a good material for optoelectronic and photovoltaic application. Originality/value: The paper presents some researches of MEH-PPV thin films deposited by spin coating method deposition on glass BK7. A MEH-PPV solution was prepared using three different solvents: chlorobenzene, chloroform and pyridine.

5

Studying of spin-coated oxad-Si properties

Weszka J., Dobrzański L. A., Jarka P., Jurusik J., Hajduk B., Bruma M., Konieczny J., Mańskowski D.

Journal of Achievements in Materials and Manufacturing Engineering

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2009

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Vol. 37, nr 2

505-511

EN

Purpose: The major aim of this paper was describing technical conditions of polymer thin film deposition by spin-coating techniques. Design/methodology/approach: Thin films of about nanometres thickness were prepared by spin-coating and their properties were studied. As a material for preparing polymer thin films oxad-Si was used. The thin films were deposited with various spinning velocity from solution of different concentration. Thin films were deposited on BK7 glass and quartz substrates. Findings: The obtained results describe influence of the solution concentration and spinning velocity on morphology and optical properties of spin-coated oxad-Si thin films. Research limitations/implications: The obtained results confirm the oxad-Si availability for optoelectronic application to be stipulated. Practical implications: The morphology and optical properties of Oxad-Si polymer thin films were described. This paper include also description of the influence of deposition conditions on properties of polymer thin films. Originality/value: The value of this paper is defining the optimal parameters of spin-coating technology for preparing oxad-Si thin film with the best properties for optoelectronics appliances. This paper describes new experimental polymeric material for spin coating technology. Results of these researches enable to develop the spin-coating technology.