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Analiza morfologii elektrod stosowanych w barwnikowych ogniwach słonecznych

Zdyb A., Lichograj P.

Czasopismo Inżynierii Lądowej, Środowiska i Architektury / Journal of Civil Engineering, Environment and Architecture

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2014

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z. 61, nr 3/II

541--546

PL

W pracy przeprowadzono badania mikroskopowe warstw nanocząstek ditlenku tytanu (TiO2) osadzonych na szkle. Tego typu struktury stosowane są jako pokrycia oświetlanej elektrody w barwnikowych ogniwach słonecznych. W budowie i funkcjonowaniu ogniwa elektroda ta jest najważniejszym elementem. Składa się ona ze szkła z warstwą przewodzącą ITO (indium tin oxide) oraz naniesionych na nią nanocząstek TiO2 z zaadsorbowanymi na powierzchni cząsteczkami barwnika organicznego. Warstwa nanocząstek, dzięki temu, że jest mezoporowata, zwiększa powierzchnię czynną w absorpcji światła. Ditlenek tytanu absorbuje promieniowane słoneczne jedynie w nadfiolecie. Zastosowanie barwnika zapewnia absorpcję światła w szerszym zakresie widma. W pracy, warstwy ditlenku tytanu otrzymywano po rozprowadzeniu nanocząstek różnych rodzajów z dodatkiem kwasu octowego lub a-terpineolu. Otrzymane struktury były wygrzewane w temperaturze 450°C w celu uzyskania lepszego kontaktu między nanocząstkami i poprawy trwałości warstwy. Do obrazowania warstw wykorzystany został mikroskop sił atomowych oraz skaningowy mikroskop elektronowy. Urządzenia te pozwalają uzyskać rozdzielczości odpowiednio: ok. 20 nm i 0,2 mim. Zastosowanie nanocząstek pochodzących z firmy Sigma Aldrich oraz EasyChem pozwoliło na otrzymanie jednorodnych warstw o rozmiarach aglomeratów 0,2-0,3 mim. Wykorzystanie nanocząstek z firmy Degussa, często opisywane w literaturze, nie dało zadowalających rezultatów przy zastosowaniu przedstawionych w pracy metod przygotowania zawiesiny. Naniesienie barwnika organicznego (alizaryny) na badane powierzchnie warstw nanoczastek nie zmienia w znaczącym stopniu uzyskanych obrazów mikroskopowych.

EN

The paper presents microscopic study of the titanium dioxide nanoparticles layers deposited on glass plates. This type of structures finds application as illuminated electrode coatings in dye-sensitized solar cells. Dye-sensitized solar cells (DSSC) have many advantages and their efficiency reached 12%, the same value as for amorphic silicon cells that are very popular in the photovoltaic market. The main part of the structure of DSSC that influences the performance of the cell is illuminated electrode which consists of glass plate with conducting ITO (indium tin oxide) layer and titanium dioxide nanoparticles covered by dye molecules. The mesoporous nanoparticle layer has high surface to volume ratio and enhances the process of light absorption. Titanium dioxide, which absorbs only ultraviolet part of solar radiation is sensibilized by dye to visible light. In this work, titanium dioxide layers were obtained by spreading of different kinds of nanoparticles (coming from various sources) in acetate acid or a-terpineol. The obtained structures were anealed in the temperature of 450°C in order to achieve better contact between nanoparticles and increase durability of the layers. The atomic force microscope and scanning electron microscope were used to obtain images of the surface. These two devices allow gaining resolution of 20 nm i 0,2 mim respectively. The homogenous layers of 0,2-0,3 mim aglomerates were obtained by using edible nanoprticles and the ones from Sigma Aldrich. Using of nanoparticles from Degussa, often described in the literature, and applying presented in this work methods of colloid preparation did not provide satisfactory results.

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Perspektywy zastosowań barwnikowych ogniw słonecznych w Polsce

Zdyb A.

Zeszyty Naukowe Politechniki Rzeszowskiej. Budownictwo i Inżynieria Środowiska

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2012

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z. 59, nr 2/II/II

891--897

PL

W referacie przedstawiono budowę, sposób działania i zalety barwnikowych ogniw słonecznych. Omówione zostały możliwości zastosowania tego typu ogniw w Polsce z uwzględnieniem oszacowania kosztów.

EN

Dye-sensitized solar cells (DSSC) provide a promising alternative concept to conventional PV devices. This paper presents structure, operation and advantages of DSSC as well as the dependence of their performance on the temperature. The estimated cost of DSSC application in Poland is also discussed.

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Selective laser sintering method of manufacturing front electrode of silicon solar cell

Dobrzański L. A., Musztyfaga M., Drygała A.

Journal of Achievements in Materials and Manufacturing Engineering

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2010

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Vol. 42, nr 1-2

111-119

EN

Purpose: The aim of the paper is to demonstrate a laser method of micro-machining front contacts of monocrystalline solar wafers. This means forming front electrodes in order to decrease their resistance. It was demonstrated, that laser processing is a promising technique for selective laser sintering (SLS) solar cell contacts compared conventional forming front grid methods. Design/methodology/approach: The topography of laser micro-machining contact formations and screen-printing were investigated using ZEISS SUPRA 25 scanning electron microscope. The materials used in the present invention are different granulation silver powders. The grain size analysis were used in order to determine their size. The transmission line model (TLM) patterns were fabricated by selective laser sintering. Findings: This work presents an initial analysis of a new selective laser sintering/melting process to contact crystalline silicon solar cells. The seed layer was created using both silver pastes and powders by a selective laser sintering, do not use up to now in Poland. These contact structures were investigated microscopically to gain a better understanding of the method and select laser micro-machining parameters, which will influence on electrical parameters of formed front side grids. Practical implications: SLS can produce parts from a relatively wide range of commercially available powder materials. The physical process can be full melting, partial melting, or liquid-phase sintering and depending on the material. The thickness of silicon solar wafer can cause some difficulties connected with adhesion electrode during contact formation process. Originality/value: In pursuing the purpose of increasing the efficiency ç of industrial crystalline solar cells to reduce costs of PV electricity, a measure to improve the front side grid is interesting – decreasing contact resistance and increasing efficiency in this way.

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Investigation of the screen printed contacts of silicon solar cells using Transmission Line Model

Dobrzański L. A., Musztyfaga M., Drygała A., Panek P.

Journal of Achievements in Materials and Manufacturing Engineering

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2010

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Vol. 41, nr 1-2

57-65

EN

Purpose: The aim of the paper is to analyze how to improve the quality of the screen printed contacts of silicon solar cells. This means forming front side grid in order to decrease contact resistance. Design/methodology/approach: The topography of screen printed contacts were investigated using ZEISS SUPRA 25 scanning electron microscope (SEM) with an energy dispersive X-ray (EDS) spectrometer for microchemical analysis. Front collection grid was created using two types of Ag pastes.The Transmission Line Model (TLM) patterns were fabricated by screen printing method on p – type Czochralski silicon Cz-Si wafer with n+ emitter without texture and with a titanium oxide (TiOx) layer as an antireflection coating (ARC). Electrical properties of contacts were investigated using TLM. Findings: This work presents a conventional analysis of a screen printing process for contact formation in the crystalline silicon solar cells. The seed layer was created using silver pasts by the screen printed metallization. These contact structures were investigated using SEM to gain a better understanding of the obtained electrical parameters. Research limitations/implications: The contact resistance of the screen-printed metallization depends not only on the kind of applied paste and firing conditions, but is also strongly influenced by the surface morphology of the silicon substrate. Practical implications: Contact formation is an important production step to be optimized in the development of high efficiency solar cells. Originality/value: The effect of co-firing different pasts (especially a past, which was prepared using silver nano-powder) on electrical properties of silicon wafers.