Wyniki wyszukiwania - BazTech

1

Effect of reaction time on the structure and optical properties of P3HT/MWCNT-OH nanocomposites

Nurazzi, Norizan Mohd, Abdullah Norli, Ngah Demon Siti Zulaikha, Halim Norhana Abdul, Sa'aya Nurul Syahirah Nasuha, Mohamad Imran Syakir

Polimery

|

2022

|

Vol. 67, nr 5

205--211

EN

In the present study, regioregular poly(3-hexylthiophene-2,5-diyl) (P3HT) coated hydroxylated multi-walled carbon nanotubes (MWCNT-OH) nanocomposites were prepared over different reaction times of non-covalent functionalization. The reaction time was set as 24, 48, 72, 96, and 120 hours. The structure and optical characteristics of nanocomposites were analyzed using Fourier-transform infrared (FTIR) and ultraviolet-visible (UV-Vis) spectroscopy, respectively. Reaction time affected prepared nanocomposites by decreasing the intensity of the P3HT/MWCNT-OH peaks gradually with increasing of the reaction time. Comparing with the pure P3HT and MWCNT-OH, the calculated energy band gap and the Urbach energy of the nanocomposites were reduced proportionally as the reaction time reached 120 hours and achieved 2.60 and 0.329 eV, respectively.

PL

Syntetyzowano hydroksylowane wielościenne nanorurki węglowe (MWCNT-OH) pokryte stereoregularnym poli(3-heksylotiofen-2,5-diylu) (P3HT) oraz zbadano wpływ czasu reakcji niekowalencyjnej funkcjonalizacji na strukturę i właściwości optyczne otrzymanego nanokompozytu. Czas reakcji wynosił 24, 48, 72, 96 i 120 godzin. W badaniach wykorzystano spektroskopię w podczerwieni z transformacją Fouriera (FTIR) oraz ultrafioletową UV-Vis. Wraz ze wzrostem czasu reakcji następowało stopniowe zmniejszenie intensywności pików P3HT/MWCNT-OH. W porównaniu z P3HT i MWCNT-OH obliczona przerwa energetyczna i energia Urbacha zmniejszały się wraz z wydłużeniem czasu reakcji i osiągnęły odpowiednio 2,60 i 0,329 eV przy czasie reakcji 120 godzin.

2

Optical and Structural Properties of Cu2O thin Film as Active Layer in Solar Cells Prepared by DC Reactive Magnetron Sputtering

Sawicka-Chudy P., Wisz G., Sibiński M., Cholewa M., Potera P., Głowa Ł., Pawełek R.

Archives of Metallurgy and Materials

|

2019

|

Vol. 64, iss. 1

243--250

EN

A series of copper oxide thin films were synthesized through direct current magnetron sputtering on glass and silicon substrates with various process parameters. Initially, optical microscopy images and their histograms were analyzed to determine the optical quality of the obtained layers and then histograms were created using Image Histogram Generator software. Next, the morphology, and cross-section and layer composition of the samples were evaluated. Finally, the transmission spectra of the thin films were recorded. Transmittance and reflection spectra of the UV–vis analysis were utilized to calculate the optical band gap, the extinction coefficient, and the absorption coefficient of the oxidized layers. Samples showed low transmittance (up to 40%) in the region of 400 to 1000 nm. The mean absorption coefficient varied from ~3 · 105 to ~6 · 105 1/cm and from ~2 · 105 to ~4 · 105 1/cm in the region of 2 eV to 3.5 eV. The extinction coefficient ranged from 0 to 0.11 in the region from 300 to 3000 nm. Reflectance of the samples was ~20% in the region of 1000 to 2500 nm and ranged from 20%-50% in the region of 1000 to 3000 nm. We verified the process parameters of the Cu2O structure to improve the quality as a buffer layer. On the basis of this preliminary analysis, we propose the most promising and future-oriented solutions in photovoltaic applications.

3

Analysis of the morphology and properties of PAN/Bi2O3 composite nanomaterials produced by electrospraying method

Tański T., Matysiak W., Markovičová L., Florek-Szotowicz N., Snopiński P., Krzemiński Ł., Wiśniowski M.

Journal of Achievements in Materials and Manufacturing Engineering

|

2015

|

Vol. 73, nr 2

176--184

EN

Purpose: The aim of the study was the preparation of the composite nanofibers with the polymer matrix reinforced by the reinforcement phase in the form of Bi2O3 ceramic nanoparticles using the electrospinning method from the 10% PAN/DMF solutions with the mass concentration of Bi2O3 nanoparticles of the order of 5 and 10%, and the investigate their morphology and physical properties as a function of the mass concentration of the reinforcing phase and the applied process parameters. Design/methodology/approach: In order to analyze the structure of the used Bi2O3 nanoparticles were used high-resolution transmission electron microscope (TEM) and X-ray diffraction analysis (XRD). To examine the morphology and chemical composition of the resulting of materials was carried out using a scanning electron microscope (SEM) with energy dispersive spectrometer (EDS). In order to analyze the physical properties of obtained composite materials was made the UV-VIS spectroscopy study, which are then used to determine the band structure of the obtained nanocomposite materials and to determine the effect of mass concentration of the reinforcing phase on the value of the energy band gap. Findings: The influence of parameters of the electrospinning process on morphology of the composite materials and influence of mass concentration of reinforcing phase on electrical structure obtained materials were determined. Practical implications: Analysis of the electrical properties resulting composite material showed that the PAN composite material reinforced ceramic Bi2O3 nanoparticles is a potentially attractive dielectric material which may be used in the field of optoelectronics. Originality/value: The Bi2O3 particles, due to their energy structure and the photocatalytic properties applied as the strengthening phase for polymers fibers and particles are attractive alternative for composite materials from PAN/TiO2 used as the photocatalytic and dielectric materials.

4

Structural And Optical Properties Of VOx Thin Films

Schneider K.

Archives of Metallurgy and Materials

|

2015

|

Vol. 60, iss. 2A

957--961

EN

VOx thin films were deposited on Corning glass, fused silica and Ti foils by means of rf reactive sputtering from a metallic vanadium target. Argon-oxygen gas mixtures of different compositions controlled by the flow rates were used for sputtering. Influence of the oxygen partial pressure in the sputtering chamber on the structural and optical properties of thin films has been investigated. Structural properties of as-sputtered thin films were studied by X-ray diffraction at glancing incidence, GIXD. Optical transmittance and reflectance spectra were recordedwith a Lambda 19 Perkin-Elmer double spectrophotometer. Thickness of the films was determined from the profilometry. It has been confirmed by XRD that the deposited films are composed mainly of V2O5 phase. The estimated optical band gap of 2.5 eV corresponds to V2O5.

PL

Cienkie warstwy VOx były nanoszone na szkło Corning metodą rozpylania magnetronowego rf. Jako katody użyto metalicznego wanadu. Były one nanoszone w komorze wypełnionej mieszaniną argonu i tlenu w różnych proporcjach przy ustalonych przepływach. Zbadano wpływ ciśnienia parcjalnego tlenu w komorze na własności strukturalne i optyczne otrzymanych warstw. Własności strukturalne cienkich warstw zostały określone metodą rozpraszania promieniowania rentgenowskiego padającego pod małymi kątami (GIXD). Widma optyczne transmitancji i odbicia zostały wykonane przy użyciu spektrometru Lambda 19 Perkin-Elmer. Grubość badanych warstw zmierzono za pomocą profilometru. Pomiary XRD potwierdziły, że otrzymane warstwy składają się głównie z fazy V2O5. Wyznaczona optycznie przerwa energetyczna wynosząca 2.5 eV odpowiada przerwie energetycznej V2O5.

5

Role of substrate temperature on the growth mechanism and physical properties of spray deposited lead oxide thin films

Suganya M, Balu A R, Usharani K

Materials Science Poland

|

2014

|

Vol. 32, No. 3

448--456

EN

Thin films of lead oxide were synthesized by cost effective spray pyrolysis technique at different substrate temperatures on glass substrates. Effect of substrate temperature on the growth mechanism and physical properties of the films was investigated. All the films were polycrystalline in nature with tetragonal structure corresponding to a-PbO. The films coated at 225 °C and 275 °C were (1 0 1) oriented, while the films deposited at 325 °C and 375 °C were (0 0 2) oriented. Above 375 °C, the pure tetragonal nature deteriorated and the peaks corresponding to orthorhombic phase were observed. The band gap value was found to be in the range of 2.3 to 2.62 eV. All the films had a resistivity of the order of 103 ohm-cm. A minimum resistivity of 0.0191 × 103 ohm-cm was obtained for the film coated at 325 °C. The activation energy increased with increase in substrate temperature.

6

Węglik krzemu - nowy materiał mikroelektroniki

Lisik Z., Stojek H.

Elektronika : prace naukowe

|

1998

|

nr 3

223-241

PL

Pierwsza fala zainteresowania węglikiem krzemu jako materiałem dla mikroelektroniki pojawiła się około 30 lat temu wraz z uzyskaniem pierwszych danych o jego unikatowych i pożądanych właściwościach fizycznych i elektrycznych. Posiada on dużą przerwę energetyczną co czyni z niego materiał wysokotemperaturowy, posiada ponadto dużą prędkość nasycenia unoszenia, duże dopuszczalne natężenie pola elektrycznego i dużą przewodność cieplną. Jest to jednak materiał bardzo trudny technologicznie i dopiero opanowanie w latach 90-tych techniki wytwarzania monokryształów o odpowiednio dużych wymiarach wywołało ponowny renesans zainteresowania SiC jako materiałem wyjściowym do produkcji szeregu przyrządów półprzewodnikowych.

EN

The first interest in silicon carbide as a material for microelectronics appeared 30 years ago when the first data showing its unique and desired physical and electrical features had been achieved. It is characterized by a wide energy band gap, what makes it a high-temperature semiconductor, a high saturation drift velocity of electrons, high permissible electrical field and, additionally, by high thermal conductivity. Its technology appeared, however, to be difficult and therefore only when the technology of large SiC monocrystals had been improved, in nineties the come-back of the interest in SiC as the basic material for manufacturing of several semiconductor devices has been observed. The review of the actual state of testing the possibilities to apply the silicon carbide in microelectronics has been introduced here. The specificity of this material has been shown; it is met in various crystallographic forms and creates crystals that show anisotropy and different electrical, and physical parameters' values. Among these species only 6H-SiC and 4H-SiC polytypes gained significant importance and are applied to manufacture experimental structures of semiconductor devices. Some examples of such devices have been introduced as well.