Wyniki wyszukiwania - Biblioteka Nauki

1

Second and third order dispersion of broadband thin-film antireflection coatings for ultrafast lasers

100%

Cojocaru E.

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2004

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tom Vol. 34, nr 1

25-29

EN

Ultrashort pulse generation relies on a high quality of the laser cavity dispersion control. Common dielectric thin-film coatings, the broadband antireflection (AR) coatings being included, may introduce great fluctuations on the group delay dispersion (GDD) and the third order dispersion (TOD) of the reflected pulse. By accumulation in time, these fluctuations may contribute to the alteration or the cease of the ultrafast regime, especially in ring laser resonators. With an insignificant computational effort, optimized broadband AR coatings may be designed to provide near-zero values of the GDD and the TOD at the expense of poor AR quality.

2

Graded SiOxNy layers as antireflection coatings for solar cells application

75%

Lipiński M. , Kluska S. , Czternastek H. , Zięba P.

Materials Science Poland

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2006

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tom Vol. 24, No. 4

1009--1016

EN

The results of theoretical optical optimization of the graded index oxynitride antireflection coatings for silicon solar cells are presented. The calculation of reflectance and absorption of layers were carried out using the Bruggeman effective medium approximation with various concentration profiles of SiNx:H in the SiO2 matrices. The experimental optical data of SiNx:H layers deposited by RF (13.56 MHz) plasma enhanced chemical vapour deposition system in various conditions were used for simulation. The highest improvement of the short-circuit current JSC (44.6%) was obtained with an SiOxNy graded layer for SiNx:H with a low refractive index (2.1 at 600 nm) and abrupt concentration profile which is characteristic of a double layer SiO 2-SiNx:H. The graded index profile can be advantageous for SiNx:H with higher indices (n greater than or equal 2.4). Moreover, the enhancement of JSC obtained by application of the antireflection coating is smaller (42.3% for n = 2.4) in this case. The improvement should be higher if the effect of surface passivation is taken into account.

3

Al2O3 antireflection coatings for silicon solar cells

75%

Dobrzański L. A. , Szindler M.

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tom Vol. 59, nr 1

13--19

EN

Purpose: The aim of this paper was to investigate changes in surface morphology and optical properties of thin films of Al2O3. Thin films were prepared using atomic layer deposition (ALD) method. Design/methodology/approach: The microanalysis was investigated by the Energy-dispersive X-ray spectroscopy EDS. The changes in surface topography was observed by the atomic force microscope AFM XE-100 and scanning electron microscope SEM. The results of roughness was obtained by the software XEI Park Systems. The measurement of thickness and dispersion of refractive index was performed using SE800 PV spectroscopic ellipsometer. The optical reflection was investigated by the spectrometer UV/VIS. Findings: Results and their analysis allow to conclude that the atomic layer deposition method enables uniform coating of smooth and complicated shapes surfaces. The thin film thickness depends only on the number of cycles, so that can be easily control the thickness of the material. Practical implications: Knowledge about the ALD Al2O3 optical parameters and the possibility to obtaining a uniform thin films show that the previously named material has a big potential in photovoltaic application. Originality/value: The paper presents some researches of aluminium trioxide thin films deposited by atomic layer deposition method on monocrystalline silicon.

4

Pomiar współczynnika odbicia zwierciadeł diod laserowych z wnęką Fabry-Perota

75%

Pruszyńska-Karbownik E. , Mroziewicz B.

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2009

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tom Vol. 50, nr 5

83-85

PL

Pokrycie zwierciadeł diod laserowych o konstrukcji krawędziowej powłokami optycznymi, dpowiednio - refleksyjnymi i antyrefleksyjnymi, jest ważnym elementem technologii tych przyrządów zarówno z punktu widzenia ich trwałości, jak i sprawności kwantowej. W artykule opisano metodę pomiaru współczynnika odbicia powłoki antyrefleksyjnej, którą opracowano pod kątem zastosowania w pomiarach diod laserowych zmontowanych na chłodnicach.

EN

It is essential for reliability and quantum efficiency of the edge emitting diode lasers to protect their mirrors with reflection and antireflection coatings, respectively. In the paper there is described a measurement method that has been developed to measure refractive index of the antireflection coating deposited on the front mirror of a diode laser bonded to a heatsink.

5

Szerokopasmowe filtry i pokrycia antyrefleksyjne na germanie dla zakresu 8÷12 µm

63%

Ciosek J. , Firak J.

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tom Vol. 51, nr 6

125-139

PL

Przedstawiono wyniki badań szerokopasmowych (8÷12 µm) pokryć antyefleksyjnych na podłożu germanowym oraz charakterystyki spektalne interferencyjnych filtrów szerokopasmowych dla zakresu spektralnego 8÷12 µm. Do projektowania filtrów i powłok antyrefleksyjnych przyjęto materiały warstwowe: Ge (nH = 4,0), ZnS (nM = 2,2) i Mirę (nL = 1,47) oraz materiały podłoża: Ge dla powłok antyrefleksyjnych oraz ZnSe dla filtrów interferencyjnych. Filtr szerokopasmowy w zakresie 8÷12 µm. wymaga zastosowania dwóch filtrów odcinających promieniowanie z zakesu 1÷7 µm. Filtry odcinające są filtrami interferencyjnymi, do konstukcji których zastosowano również german, Mirę i ZnS. Konstrukcje filtrów podstawowego i odcinających zaprojektowane zostały z uwzględnieniem możliwości technicznych urządzenia próżniowego BAK 550 firmy Balzers.

EN

The study presents the results of investigation of broadband antireflection coatings on the germanium substrate and the spectral characteristics of broadband interference filter for 8÷12 µm. To design of filters and antireflection of broadband folowing layer materials weve taken: Ge (nH = 4,0), ZnS (nM = 2,2), Mira (nL = 1,47) and substrate materials: Ge for antireflection coatings and ZnSe for interference filters. The broadband filter for 8÷12 µm demands to use two filters cutting the radiation in the range 1÷7 µm. For the cutting filters there are used the materials: Ge, Mira and ZnS. There were considered technical possibility of BAK 550 Balzers equipment in the design of main and cutting filters construction.

6

Otrzymywanie powłok antyrefleksyjnych na szkle techniką zol-żel

63%

Nocuń M. , Kwaśny S. , Skuba P.

Materiały Ceramiczne

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2010

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tom T. 62, nr 1

46-50

PL

Przedmiotem badań było otrzymywanie warstw antyrefleksyjnych wytwarzanych techniką zol-żel. W szczególności analizowano stabilność długoczasową zolu. Badano również wpływ starzenia na parametry antyrefleksyjne i porowatość powłok. Współczynnik załamania, porowatość i grubość warstw wyznaczono w oparciu o pomiary elipsometryczne. Stwierdzono, że z czasem starzenia współczynnik załamania powłoki maleje co pogarsza jej własności antyrefleksyjne. Porowatość wzrasta z ok. 26%, dla roztworu wyjściowego, do ok. 50% po czasie 185 dni. Badany zol wykazuje technologiczną stabilność w czasie ok. 30 dni.

EN

Preparation of antireflection coatings by a sol-gel method was the subject of this study. In particular, long-term stability was the main concern. The influence of aging on antireflection parameters and porosity was also studied. Refractive index, porosity and thickness of the layers were estimated on the base of ellipsometric measurements. It was found that the refractive index lowers with time of aging making worse antireflection properties of the coatings. Porosity increases from 26% for the freshly prepared sol up to about 50% after 185 days of aging. The sol of studied composition is technologically stabile within 30 days.

7

Struktura i własności warstw Al₂O₃ osadzonych metodą ALD na krzemowych ogniwach fotowoltaicznych

63%

Szindler M. , Szindler M.

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2018

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tom Vol. 59, nr 9

9--11

PL

W pracy zbadano możliwości zminimalizowania współczynnika odbicia światła, a w konsekwencji zwiększenia sprawności wytwarzanych krzemowych ogniw fotowoltaicznych, poprzez wytworzenie cienkiej warstwy antyrefleksyjnej Al₂O₃ metodą atomowego osadzania warstw. Badania morfologii powierzchni warstw wykonano przy użyciu skaningowego mikroskopu elektronowego, z kolei strukturę zbadano przy użyciu dyfraktometru rentgenowskiego. W celu okreslenia własności optycznych cienkich warstw Al₂O₃ wykonano badania współczynnika odbicia światła przy użyciu spektrofotometru. Ogniwo fotowoltaiczne z osadzoną w temperaturze 300°C metodą ALD warstwą antyrefleksyjną przy zadanej liczbie cykli 830 osiągnęło sprawność 12,51%, podczas gdy sprawność ogniwa referencyjnego bez warstwy antyrefleksyjnej wyniosła 7,22%.

EN

The main goal of the study was to examine the possibility of minimizing the reflectance of light, and consequently increasing the efficiency of the produced silicon solar cells, by creating an Al₂O₃ antireflection coating by atomic layer deposition method (ALD). Surface layer morphology studies were performed by using scanning electron microscopy, while the structure was examined by using an X-ray diffractometer. In order to determine the optical properties of the Al₂O₃ thin films, light reflectance measurements were performed using a spectrophotometer. The solar cell with deposited antireflection coating by the ALD method with a 830 number of cycles at 300°C reached the efficiency of 12.51%, while the efficiency of the reference cell is 7.22%.

8

Effect of dislocation density on the efficiency of multicrystalline silicon solar cells

51%

Benmohamed Z. , Remram M.

Materials Science Poland

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2007

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tom Vol. 25, No. 1

243--249

EN

The behaviour of structural defects is still one of the major problems in multicrystalline silicon. The properties of solar cells made from these materials are mainly determined by dislocations, grain boundaries and intragrain defect impurities such as oxygen and carbon. Interactions between dislocations and impurities are also an important factor influencing the minority carrier diffusion length and then multicrystalline solar cells performances. In this paper, the effect of dislocations on minority carrier diffusion length is analysed and discussed. We carried out the calculation on the cell efficiency of multicrystalline silicon solar cell obtained from wafers cut put of ingots grown by Polix of Photowatt and Sitix of Sumitomo. A comparison between solar cells efficiency for the two materials outlined above is presented. Performances of the cells are estimated according to the last technological processes developed. The analyses have also been carried out to optimize solar cell performances by combining the effect of a double antireflection coating and back surface field.

9

Rare earth oxide films: their preparation and characterization

44%

Wiktorczyk T.

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tom Vol. 31, nr 1

5-33

EN

Summarises the results of our investigations dealing with preparation of rare earth oxide films and examinations of their physical properties. Different deposition methods have been applied for fabrication of these films and rare-earth-oxide-based thin film coatings. The main results concerning film microstructure and optical properties in the wavelength range from the UV up to the IR are presented. Electrical and dielectric studies have been carried out in the time domain and in the frequency domain (from very low frequencies up to radio frequencies) for selected rare earth oxides. MIM sandwich-type structures have been fabricated for this aim. Trapping levels in these oxides have been investigated. The complex impedance diagnostics was applied to the analysis of the volume of the R/sub 2/O/sub 3/ film and interfacial properties (metal/insulator barriers) of M/R/sub 2/O/sub 3//M thin film structures.