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1

Tris(8-hydroxyquinoline)aluminium in a polymer matrix as an active layer for green OLED applications

Sypniewska Małgorzata, Pokladko-Kowar Monika, Kaczmarek-Kedziera Anna, Brumboiu Iulia E., Figà Viviana, Apostoluk Aleksandra, Song Peng, Liu Junyan, Szczesny Robert, Gondek Ewa, Derkowska-Zielinska Beata

Opto-Electronics Review

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2023

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Vol. 31, No. 2

art. no. e146105

EN

Tris(8-hydroxyquinoline)aluminium with poly(N-vinylcarbazole) (Alq₃:PVK) or polystyrene sulfonate (Alq₃:PSS) were deposited by spin-coating on glass and silicon substrates. SEM measurements show that relatively smooth thin films were obtained. Fourier transform infrared measurements were performed to confirm the composition of the samples. The optical properties of thin films containing Alq₃:PVK and Alq₃:PSS were characterised using absorption spectroscopy and spectroscopic ellipsometry. It was found that the absorption spectrum of Alq₃:PVK is characterised by four bands, while for Alq₃:PSS only three bands are visible. The photoluminescence of the studied thin layers shows a peak with a maximum at about 500 nm. Additionally, cyclic voltammetry of Alq₃ is also presented. Theoretical density functional theory calculations provide the insight into the interaction and nature of Alq₃:PVK and Alq₃:PSS excited states. Finally, the organic light-emitting diode (OLED) structure based on Alq₃:PVK was fabricated and showed strong electroluminescence with a green emission at 520 nm. The results of the device show that the ITO/PEDOT:PSS/Alq₃:PVK/Ca/Al system can be useful for the production of low-cost OLEDs with Alq₃:PVK as an active layer for future lighting applications.

2

Badanie rozkładu grubości powierzchni cienkich warstw metodą elipsometrii spektroskopowej

Hajduk Barbara, Jarka Paweł, Nitschke Paweł

LAB Laboratoria, Aparatura, Badania

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2019

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R. 24, nr 1

6--8

3

Characterization of a-C:N:H, a-SiNx:H and a-SiCx:Ny:H layers deposited on various substrates

Dyndał K.

Inżynieria Materiałowa

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2018

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Vol. 39, nr 6

198--203

EN

Amorphous hydrogenated carbon nitride layers, a-C:N:H, amorphous hydrogenated silicon nitride layers, a-SiNx:H and amorphous hydrogenated silicon carbonitride, a-SiCxNy:H, layers, fabricated on borosilicate glass and (001) oriented Czochralski silicon wafers by plasma assisted chemical vapour deposition, 13.56 MHz, were compared in this study. For reliable comparison the processing parameters, except temperature, were kept at the same level in each experiment. The layers containing silicon were grown at 473 K, while the layers without silicon were grown at 298 K. Methane, nitrogen and silane gaseous were used as carbon, nitrogen and silicon gaseous precursors respectively. The layers were subjected to structural studies by FTIR spectroscopy. The thicknesses of the layers and optical constants’ functions: refractive index n (λ) and extinction coefficient k (λ), were determined by spectroscopic ellipsometry. Wollam M2000 ellipsometer was used to measure ellipsometric angles Psi (Ψ) and Delta (Δ) within 200÷1800 nm spectral range at three different angles of incidence 65°, 70° and 75°. The differences between structure and properties of the layers were indicated, as well as differences between the same layers deposited on various substrates. The results show that the layers grown on glass and Si are similar materials. Optical constants do not differ much. However, clear differences are seen, when thicknesses of the layers are compared. As a rule, the layers deposited on glass are thicker. A proposed explanation is related to the energy of the bonds C–O and Si–O for the layers deposited on glass and C–Si and Si–Si when the layers were deposited on Si wafers.

PL

Metoda PACVD należy do obiecujących metod inżynierii powierzchni. Pozwala modyfikować warstwę wierzchnią różnego typu materiałów, jak metale, szkło, a nawet polimery, z zastosowaniem zróżnicowanych warstw pod względem składu chemicznego i struktury. Zastosowanie plazmy jako ośrodka niekonwencjonalnej syntezy pozwala obniżyć temperaturę procesu, co jest szczególnie korzystne w przypadku podłoży wrażliwych na działanie wysokiej temperatury. Technika PACVD wymaga ścisłego określenia parametrów procesu: temperatury, ciśnienia, mocy generatora plazmy, czasu osadzania, rodzaju i przepływu gazowych reagentów. Celem tej pracy jest wyznaczenie i porównanie grubości oraz właściwości optycznych (współczynników załamania i współczynników ekstynkcji) warstw osadzonych na szkle borokrzemowym i monokrystalicznym krzemie Si (001) z zastawaniem metody PACVD, 13,56 MHz. Otrzymane i badane były amorficzne uwodornione warstwy: węgla dotowanego azotem (a-C:N:H), azotku krzemu (a-SiNx:H) oraz węgloazotku krzemu (a-SiCxNy:H).

4

Optimization of radio frequency inductively coupled plasma enhanced chemical vapour deposition process of diamond-like carbon films

Kijaszek W., Oleszkiewicz W.

Optica Applicata

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2016

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Vol. 46, nr 2

167--172

EN

The diamond-like carbon materials have unique mechanical, optical, electrical and chemical properties. The material is commonly applied in automotive industry, medicine and in other everyday life products. However, the diamond-like carbons are not used in micro- and optoelectronics on a wider scale due to technological problems. The application of the diamond-like carbon films in electronic structure is limited because the standard methods do not ensure that the quality and properties of the deposited film will be satisfactory for a specific application. On the other hand, more sophisticated methods that allow manufacturing the diamond-like carbon film with adequate properties, such as microwave assisted chemical vapour deposition, require heating of the substrate to high temperature (above 1000°C). The solution to the problem is the radio frequency inductively coupled plasma enhanced chemical vapour deposition method that allows deposition of the diamond-like carbon films with satisfactory properties and the process can be carried out at room temperature. In the paper, basic information and issues concerning the diamond-like carbon films manufacturing technology by radio frequency inductively coupled plasma enhanced chemical vapour deposition method will be explained. The diamond-like carbon films were investigated by the Raman scattering spectroscopy and the spectroscopic ellipsometry.

5

Investigation of optical properties of silicon oxynitride films deposited by RF PECVD method

Kijaszek W., Oleszkiewicz W., Zakrzewski A., Patela S., Tłaczała M.

Materials Science Poland

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2016

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Vol. 34, No. 4

868--871

EN

In this study, the authors deposited silicon oxynitride films by Radio Frequency Plasma Enhanced Chemical Vapour Deposition (RF PECVD) method. The research explores the relationship between the deposition process parameters and the optical properties of the deposited SiOxNy films. The optical constants of SiOxNy films were measured and calculated by spectroscopic ellipsometry method. Additionally, the authors investigated the possibility of controlling the deposited film composition by the flow ratio of different gaseous precursors: ammonia (NH3), diluted silane (2%SiH4 /98%N2), nitrous oxide (N2 O) and nitrogen (N2). The gas mixture introduced to the working chamber during the growth of the film has the influence on the Si–O and Si–N bonds formation and the ratio between these bonds determines the refractive index of the deposited film.

6

Substrate temperature effect on the nanoscale multilayer ZnS/Ag/ZnS for heat mirror application

Kavei G., Nikbin S.

Materials Science Poland

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2015

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Vol. 33, No. 4

760--766

EN

Nanoscale multilayers of ZnS/Ag/ZnS were deposited on Corning glass substrates at different substrate temperatures. The depositions were carried out in high vacuum using electron beam deposition technique at 20, 60, 100 and 150 degrees C, respectively. The optical and electrical performance of each single layer and the accomplished ZnS/Ag/ZnS multilayer system were characterized using spectroscopic ellipsometry analysis, XRD and finally AFM. Based on these analyses and associated theories, such as the characteristic matrix theory, the optimized multilayer system was speculated and tested. Crystallographic structures of the films were studied by X-ray diffraction. In addition to X-ray diffraction, morphological characterizations were carried out by AFM in order to observe the deposited particle size, packing and roughness of the films. The optimum performance was achieved at the substrate temperature of 60 degrees C.

7

Surface morphology and optical properties of Al₂O₃ thin films deposited by ALD method

Dobrzański L. A., Szindler M., Szindler M.M.

Archives of Materials Science and Engineering

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2015

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Vol. 73, nr 1

18--24

EN

Purpose: The paper presents the results of investigations on the changes in surface morphology, roughness, and thickness of the prepared aluminium oxide thin films as dependent on conditions of the thin films preparation. Design/methodology/approach: Thin films have been prepared with use of atomic layer deposition (ALD) method. The changes of surface morphology have been observed in topographic images performed with the atomic force microscope (AFM). Obtained roughness parameters have been calculated with XEI Park Systems software. The thickness distribution have been measured with spectroscopic ellipsometry. The optical transmission spectra have been measured with UV-Vis spectrophotometry. Findings: Results and their analysis show that the atomic layer deposition method allows the deposition of homogenous thin films of Al2O3 with the desired geometric characteristics and good optical properties. Practical implications: The technology of atomic layer deposition of aluminium oxide thin films causes that mentioned thin films are good potential material for optics, optoelectronics and photovoltaics. Originality/value: The paper presents results of investigations on aluminum oxide thin films prepared with atomic layer deposition method on glass substrate.

8

Technika elipsometrii spektroskopowej jako metoda monitorowania jakości powierzchni materiałów grupy SrxBa1-xNb2O6

Dorywalski K., Patryn A.

Przegląd Elektrotechniczny

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2014

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R. 90, nr 9

22-25

PL

W artykule przedstawiono możliwość zastosowania techniki elipsometrii spektroskopowej do szybkiego i nieinwazyjnego monitorowania jakości powierzchni fotorefrakcyjnych kryształów SrxBa1-xNb2O6. Przedstawiono model optyczny materiału z chropowatą warstwą powierzchniową, który umożliwia precyzyjne wyznaczenie wielkości nierówności powierzchni w procesie dopasowania symulowanych krzywych teoretycznych oraz eksperymentalnych funkcji optycznych. Otrzymane wielkości stopnia chropowatości przy pomocy techniki elipsometrii zbliżone są do odpowiednich uzyskanych techniką mikroskopii sił atomowych.

EN

The article presents the capabilities of spectroscopic ellipsometry as a fast and nondestructive tool for monitoring of surface quality of photorefractive SrxBa1-xNb2O6 crystals. Optical model with surface roughness layer is shown which allows to determine precisly the values of surface roughness in the fitting procedure of modeled and experimental optical functions. The obtained surface roughness quantities by spectroscopic ellipsometry and atomic force microscopy are in good agreement.

9

Characterization of optical and electrical properties of transparent conductive boron-doped diamond thin films grown on fused silica

Bogdanowicz R.

Metrology and Measurement Systems

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2014

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Vol. 21, nr 4

685--698

EN

Abstract A conductive boron-doped diamond (BDD) grown on a fused silica/quartz has been investigated. Diamond thin films were deposited by the microwave plasma enhanced chemical vapor deposition (MW PECVD). The main parameters of the BDD synthesis, i.e. the methane admixture and the substrate temperature were investigated in detail. Preliminary studies of optical properties were performed to qualify an optimal CVD synthesis and film parameters for optical sensing applications. The SEM micro-images showed the homogenous, continuous and polycrystalline surface morphology; the mean grain size was within the range of 100-250 nm. The fabricated conductive boron-doped diamond thin films displayed the resistivity below 500 mOhm cm-1 and the transmittance over 50% in the VIS-NIR wavelength range. The studies of optical constants were performed using the spectroscopic ellipsometry for the wavelength range between 260 and 820 nm. A detailed error analysis of the ellipsometric system and optical modelling estimation has been provided. The refractive index values at the 550 nm wavelength were high and varied between 2.24 and 2.35 depending on the percentage content of methane and the temperature of deposition.

10

Sol-gel Al2O3 antireflection coatings for silicon solar cells

Dobrzański L.A., Szindler M., Szindler M.M., Hajduk C.

Archives of Materials Science and Engineering

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2014

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Vol. 67, nr 1

24-31

EN

Purpose: This paper presents the results of investigations on morphology and optical properties of the prepared aluminium oxide thin films Design/methodology/approach: Thin films were prepared with use of sol-gel spin coating method. The changes of surface morphology were observed in topographic pictures performed with the atomic force microscope AFM. Obtained roughness coefficients values were generated with XEI Park Systems software. The thickness distribution were checked with spectroscopic ellipsometry with use of mapping mode. The optical reflection spectra were measured with UV-Vis spectrophotometry. Findings: Results and their analysis show that the sol-gel method allows the deposition of homogenous thin films of Al2O3 with the desired geometric characteristics and good optical properties. Practical implications: The technology of sol-gel aluminium oxide thin films deposition causes that mentioned thin films are good potential material for optics, optoelectronics and photovoltaics. Originality/value: The paper presents some results of investigations on aluminium oxide thin films prepared with sol-gel spin coating method on polished monocrystalline silicon.

11

Parametry optyczne cienkich warstw krzemionkowych na podłożach krzemowych

Skoczek E., Cisowski J., Karasiński P., Jaglarz J., Jarząbek B.

Materiały Ceramiczne

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2012

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T. 64, nr 2

282-285

PL

W pracy przedstawiono wyniki badań właściwości optycznych cienkich warstw krzemionkowych. Badane warstwy zostały wytworzone w technologii zol-żel i naniesione na krzemowe podłoża metodą zanurzeniową. Badania przeprowadzono metodami elipsometrycznymi i spektrofotometrycznymi, a analiza otrzymanych wyników pozwoliła na wyznaczenie parametrów optycznych badanych warstw takich jak zależności dyspersyjne współczynników załamania oraz ekstynkcji. Dodatkowo, wyznaczono grubości warstw oraz ich porowatość. Ze względu na niską wartość współczynnika załamania (1,22-1,25) warstwy krzemionkowe są stosowane jako powłoki antyrefleksyjne oraz elementy światłowodów planarnych.

EN

Studies of optical properties of thin silica fi lms are shown in the paper. The films were manufactured by the sol-gel method combined with spreading on a silicon substrate by immersing. The studies were performed by ellipsometric and spectrophotometric methods to determine optical characteristics of the films such as dispersion dependences of refractive indices or extinction coeffi cients. Moreover, the thickness and porosity of the films were determined. The silica layers are used as antireflective coatings and components of planar optical fibres due to low values of refractive index (1,22-1,25).

12

Elipsometryczna metoda określania naprężeń w strukturach MOS

Rzodkiewicz W.

Elektronika : konstrukcje, technologie, zastosowania

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2011

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Vol. 52, nr 10

98-101

PL

Analiza widm optycznych dostarcza wielu cennych informacji na temat właściwości fizycznych materiałów. W tym celu stosuje się funkcję dielektryczną, opisującą wpływ zewnętrznego pola elektrycznego na optyczne właściwości materiałów półprzewodnikowych. W pracy tej do analizy widm zespolonej funkcji dielektrycznej, zarówno implantowanego, jak i nie implantowanego krzemu, posłużyła elipsometria spektroskopowa w połączeniu z modelem pochodnych ułamkowych FDS (Fractional Derivatives Spectrum). Dokładne wyekstrahowanie parametrów punktów krytycznych przy użyciu tych dwóch metod stało się pomocne przy określeniu naprężeń mechanicznych w warstwie półprzewodnika struktury MOS.

EN

Optical spectra analysis provides a wealth of information on physical properties of various semiconductor materials. Fractional Derivative Spectrum (FDS) technique is especially interesting when the limitations of the standard treatment are occurred. In this paper we present the FDS with spectroscopic ellipsometry method for analyze of the optical spectra of silicon surfaces (after oxidation, after implantation and high pressure-high temperature treatment). On the basis of extracted Van Hove singularities by FDS and SE methods, the stresses in the semiconductor layer of MOS strucutre were determined.

13

Spectroscopic ellipsometry studies of elastic and non-elastic strains in Si-SiO2 systems

Rzodkiewicz W., Panas A.

Zeszyty Naukowe Politechniki Poznańskiej. Budowa Maszyn i Zarządzanie Produkcją

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2010

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Nr 14

77-82

EN

To understand generation mechanisms of elastic and non-elastic strains (decompaction and compaction) in the Si-SiO2 system, it is useful to determine the structural changes of silica under stress. The main aim of the work was to find the proper analytical relationship between refractive index n and density of SiO2 layers on silicon substrates. Such p(n) relationship will give possibility to define the elastic and non-elastic strains in SiO2 layers on silicon substrates. For the sake of the quality of silicon substrates surface, before thermal oxidation, all substrate wafers were undergone the interferometrie measurements. On the other hand, ellipsometric measurements by using Variable Angle Spectroscopic Ellipsometer of J.A. Woollam Company allowed determination of thicknesses and refractive indexes of silicon dioxide layers. The Hill approximation function curve with three parameters turned out to be the best fitting curve for the experimental data. The Hill curve shows saturation for the density of the oxide to the value c.a. 4.53 g/cm3.

PL

Głównym celem tejże pracy było opracowanie analitycznej zależności funkcjonalnej pomiędzy współczynnikiem załamania n, a gęstością p warstw SiO2 na podłożach krzemowych. Na podstawie obliczonych wartości objętości i zważonych mas warstw SiO2 określano gęstość warstwy tlenku. W ten sposób otrzymaną gęstość warstwy tlenku porównywano z wartościami gęstości warstw SiO2 uzyskanymi na podstawie wyznaczonych metodą elipsometrii spektroskopowej współczynników załamania i zastosowania literaturowych zależności. W oparciu o wyniki gęstości otrzymane dla warstw dokonano analizy dopasowywania danych w celu znalezienia odpowiedniej krzywej odzwierciedlającej właściwą zależność gęstości tlenku od współczynnika załamania. Najlepszą krzywą dopasowania do danych eksperymentalnych okazała się funkcja Hilla z trzema zmiennymi parametrami. Tak określona zależność p(n) pomoże określać odkształcenia (sprężyste i niesprężyste) w warstwach SiO2 na podłożach krzemowych.

14

Spectroscopic Ellipsometry Analysis of Rapid Thermal Annealing Effect on MBE Grown GaAs1-x-Nx

Sedrine N., Rihani J., Harmand J., Chtourou R.

Journal of Telecommunications and Information Technology

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2009

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nr 1

51-56

EN

We report on the effect of rapid thermal annealing (RTA) on GaAs1-x-Nx layers, grown by molecular beam epitaxy (MBE), using room temperature spectroscopic ellipsometry (SE). A comparative study was carried out on a set of GaAs1-x-Nx as-grown and the RTA samples with small nitrogen content (x = 0.1%, 0.5% and 1.5%). Thanks to the standard critical point model parameterization of the GaAs1-x-Nx extracted dielectric functions, we have determined the RTA effect, and its nitrogen dependence. We have found that RTA affects more samples with high nitrogen content. In addition, RTA is found to decrease the E1 energy nitrogen blueshift and increase the broadening parameters of E1, E1+?1, E'0 and E2 critical points.

15

Ellipsometric spectroscopy studies of compaction and decompaction of Si-SiO2 systems

Rzodkiewicz W., Panas A.

Journal of Telecommunications and Information Technology

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2007

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nr 3

44-48

EN

The influence of the strain on the optical properties of Si-SiO2 system has been investigated by spectroscopic ellipsometry (SE), interferometry and weighing methods. Subtle changes of densification (compaction degree) in silicon dioxide layers on silicon substrates have been determined by weight technique (relying on measurements of the silicon dioxide layer mass and calculations of the volume). Elastic stress in the oxide layers has been measured by Fizeau fringes image analysis method. A comparison is made between the density of the silicon dioxide (r) and the results of calculations made using r = f = (n) relations (where n is the refractive index) given in the literature.