Wyniki wyszukiwania - BazTech

1

The application of magnetic self-filter to optimization of AIN film growth process during the impulse plasma deposition synthesis

Chodun R., Nowakowska-Langier K., Okrasa S., Zdunek K.

Materials Science Poland

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2016

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Vol. 34, No. 1

126--131

EN

This work presents the very first results of the application of plasma magnetic filtering achieved by a coil coupled with an electrical circuit of a coaxial accelerator during the synthesis of AlN thin films by use of Impulse Plasma Deposition method (IPD). The uniqueness of this technical solution lies in the fact that the filter is not supplied, controlled and synchronized from any external device. Our solution uses the energy from the electrical circuit of plasma accelerator. The plasma state was described on the basis of OES studies. Estimation of the effects of plasma filtering on the film quality was carried out on the basis of characterization of structure morphology (SEM), phase and chemical composition (vibrational spectroscopy). Our work has shown that the use of the developed magnetic self-filter improved the structure of the AlN coatings synthesized under the condition of impulse plasma, especially by the minimization of the tendency to deposit metallic aluminum droplets and columnar growth.

2

Effect of TEA on characteristics of CdS/PbS thin film solar cells prepared by CBD

Sattarian H., Tohidi T., Rahmatallahpur S. H.

Materials Science Poland

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2016

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Vol. 34, No. 3

540--547

EN

In this study, a solar cell with a glass/ITO/CdS/PbS/Al structure was constructed. Both window (CdS) and absorption (PbS) layers were deposited by chemical bath deposition (CBD) method. The CdS window layer was deposited on ITO-glass. The PbS nanocrystalline thin film was prepared with and without triethanolamine on CdS films at bath temperature of 25 °C. CdS and PbS nanocrystals were identified using XRD and SEM. The cells are photosensitive in a large spectral range (at visible and near infrared regions). The cell with absorbing layer obtained from the bath without TEA has higher efficiency with the following parameters: the open circuit voltage (Voc) is 275 mV, short circuit current (J sc) is 12.24 mA/cm 2, maximum voltage (V max) is 165 mV and maximum current (J max) is 7.11 mA/cm 2with the efficiency η = 1.31 %, fill factor FF is 32 % under the illumination intensity of 90 mW/cm2. The cells have an area of 0.15 cm 2.

3

Synthesis of multicomponent metallic layers during impulse plasma deposition

Nowakowska-Langier K., Chodun R., Zdunek K.

Materials Science Poland

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2015

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Vol. 33, No. 4

841--846

EN

Pulsed plasma in the impulse plasma deposition (IPD) synthesis is generated in a coaxial accelerator by strong periodic electrical pulses, and it is distributed in a form of energetic plasma packets. A nearly complete ionization of gas, in these conditions of plasma generation, favors the nucleation of new phase of ions and synthesis of metastable materials in a form of coatings which are characterized by amorphous and/or nanocrystalline structure. In this work, the Fe-Cu alloy, which is immiscible in the state of equilibrium, was selected as a model system to study the possibility of formation of a non-equilibrium phase during the IPD synthesis. Structural characterization of the layers was done by means of X-ray diffraction and conversion-electron Mossbauer spectroscopy. It was found that supersaturated solid solutions were created as a result of mixing and/or alloying effects between the layer components delivered to the substrate independently and separately in time. Therefore, the solubility in the Fe-Cu system was largely extended in relation to the equilibrium conditions, as described by the equilibrium phase diagram in the solid state.

4

Methods of optimization of reactive sputtering conditions of Al target during AlN films deposition

Chodun R., Nowakowska-Langier K., Zdunek K.

Materials Science Poland

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2015

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Vol. 33, No. 4

894--901

EN

Encouraged by recent studies and considering the well-documented problems occurring during AlN synthesis, we have chosen two diagnostic methods which would enable us to fully control the process of synthesis and characterize the synthesized aluminum nitride films. In our experiment we have compared the results coming from OES measurements of plasma and circulating power characteristics of the power supply with basic features of the deposited layers. The dual magnetron system operating in AC mode was used in our studies. Processes of aluminum target sputtering were carried out in an atmosphere of a mixture of argon and nitrogen. The plasma emission spectra were measured with the use of a monochromator device. Analyses were made by comparing the positions and intensities of spectral lines of the plasma components. The results obtained allowed us to characterize the sputtering process under various conditions of gas mixture compositions as well as power distribution more precisely, which is reported in this work. The measured spectra were related to the deposition rate, the structure morphology of the films and chemical composition. Our work proved that the use of plasma OES and circulating power measurements make possible to control the process of sputtering and synthesis of deposited films in situ.

5

Optical properties of Eu(III) doped nanocrystalline films of TiO2

Hreniak A., Nyk M., Hreniak D., Stręk W., Kępiński L., Misiewicz J., Maruszewski K.

Materials Science Poland

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2004

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Vol. 22, No. 3

227--234

EN

The synthesis of europium (III) doped nanocrystalline TiO2 films is described. The morphology and structure of the films were determined by transmission electron microscopy (TEM) and the selected area of electron diffraction (SAED) method. The photoluminescence (PL), lifetimes and cathodoluminescence (CL), recorded at room temperature, are reported. It has been found that the cathodoluminescence characteristics are significantly different from the photoluminescence ones. It is concluded that different Eu3+ sites contribute to the optical behaviour of Eu3+:TiO2 films.