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The influence of reduced graphene oxide on the structure of the electrodes and the properties of dye-sensitized solar cells

Dobrzański L. A., Prokopiuk vel Prokopowicz M.

Archives of Materials Science and Engineering

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2016

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Vol. 77, nr 1

12--30

EN

Purpose of the paper: The aim of the research is to investigate the influence of the structure and chemical composition of the surface layers containing reduced oxide graphene on the properties of dye-sensitized solar cells, and to determine the correlation between the morphology and physicochemical properties of reduced graphene oxide and the electrical and optical properties of dye-sensitized solar cells, which will result in the desired effects reducing production costs and increasing the efficiency of dye cells. Design/methodology/approach: Complete manufacturing technology of dye-sensitized solar cells included the selection of the conditions of the thermal reduction of graphene oxide, the development of manufacturing technology of photoanode with and without reduced graphene oxide, the development of manufacturing technologies of counter electrodes with the reduced graphene oxide and the production of dye-sensitized solar cells by combining photoanode and counter electrode and filling the space between them by the electrolyte. Findings: A reduced graphene oxide layers applied to a glass substrate with transparent conductive oxide, used as a counter electrode and photoanode effect on reducing the degree of recombination and increasing electrochemical properties, which makes them important factors in increasing the efficiency of photovoltaic cells and reduce their manufacturing costs. Research limitations/implications: Dye-sensitized solar cells research develop in the direction to increase their efficiency and reduce manufacturing costs, among others, by modifying the chemical composition and structure of the main components: photoanode and counter electrode. Using one of the most expensive materials in the world - a platinum as a catalytic layer causes a significant increase in production costs. For this reason, it is important to search for new materials that can replace the expensive platinum. Practical implications: Developed in this work producing technology of photoanode and the counter electrode containing reduced graphene oxide is an attractive alternative to dye-sensitized solar cell by reducing the manufacturing cost by eliminating costly layer of platinum while maintaining a relatively high efficiency, high transmittance and low resistance of charge transfer at the interlayer counter electrode/electrolyte. Originality/value: In the paper, the reduced graphene oxide was applied as both photoanode and the counter electrode in dye-sensitized solar cells.

2

Trasowanie ścieżek prądowych w betonie między przeciwelektrodą i elektrodą badaną w pomiarach impedancyjnych zbrojenia

Jaśniok M.

Roczniki Inżynierii Budowlanej

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2015

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z. 15

5--10

EN

The paper concerns the widely understood advanced diagnosis of corrosion of reinforced concrete structures. The subject of analysis was the method of electrochemical impedance spectroscopy (EIS). At the outset the general assumptions of the original '3D' model was described for analysis and simulation of impedance spectra obtained for reinforcing steel in concrete. Then, the way of routing of electrical conductivity paths in concrete between the counter electrode and the working electrode (rebar)was described in details. Mathematical expression were given to allow determination of a spatial grid nodesin concrete, which are also the nodes of the conductivity paths. The described conductivity of electrical paths are the elongated curvilinear concrete solids and demarcate the active zone of concrete in conduction of alternating current during impedance measurements of steel in concrete.

3

Transparent platinum counter electrode for dye-sensitized solar cells

Dobrzański L. A., Szindler M., Prokopiuk vel Prokopowicz M., Drygała A., Lukaszkowicz K., Jung T., Szindler M.M.

Journal of Achievements in Materials and Manufacturing Engineering

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2015

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Vol. 68, nr 1

5--10

EN

Purpose: The objective of this article was to compare the surface morphology and structure of thin films deposited by screen printing and sputtering (PVD) methods. Design/methodology/approach: The morphology of the surface of the platinum thin films was performed using a scanning electron microscope Zeiss Supra 35. The detailed surface topography studies were made using an atomic force microscope XE-100 Park systems company. Roughness parameters were calculated using the software XEI. The whole study was complemented by X-ray crystallography. Findings: Results and their analysis show that the physical vapour deposition method allows the deposition of thin films with a better quality than the screen printing method. Practical implications: The platinum thin films are good potential material for electronics, optoelectronics and photovoltaics. Originality/value: The paper presents results of investigations on platinum thin films prepared with screen printing and sputtering (PVD) methods on a FTO glass substrate.

4

Graphene oxide film as semi-transparent counter electrode for dye-sensitized solar cell

Dobrzański L. A., Prokopiuk vel Prokopowicz M., Lukaszkowicz K., Drygała A., Szindler M.

Journal of Achievements in Materials and Manufacturing Engineering

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2015

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Vol. 73, nr 1

13--20

EN

Purpose: The aim of the paper is to fabricate semi-transparent graphene oxide counter electrodes for dye-sensitized solar cells. Design/methodology/approach: A thermal reduction is applied to decreased the amount of surface oxygen functionalities on graphene sheets. For this purpose thermal treatments in oven in 250°C and 500°C were used. Graphene oxide materials were mixed with PEDOT:PSS and then deposited on FTO glass by spin coating method. PEDOT:PSS was added to graphene oxide to increase conductivity and enhance film forming ability. Findings: Ultraviolet-visible spectroscopy measurement was carried out to monitor the degree of oxidation for the graphene samples. It has been found that annealing of graphene oxide counter electrodes under inert atmospheres enable a better ordering of graphene oxide films and also cause losing an oxygen functional groups, that makes layers become denser and smother, with a lower surface roughness, and thus less transparent. Research limitations/implications: It has been found that due to development of the technology of dye-sensitized solar cells with graphene oxide counter electrode, it is possible to lowering a production costs by replacing a costly platinum. It is advisable to take into account in the further experiments application of counter electrode on different kinds of substrates in the selected process parameters, and research for using them in DSSC cells mass production. Practical implications: DSSC cells are an interesting alternative to silicon solar cells. Presented in this paper results showed possibilities of modify dye-sensitized solar cells by replacing costly platinum. Originality/value: It was shown that dye-sensitized solar cells with graphene oxide counter electrode can be used in building integrated photovoltaic.

5

Influence of carbon nanotubes on properties of dye-sensitised solar cells

Dobrzański L. A., Wierzbicka A., Drygała A., Lukaszkowicz K.

Archives of Materials Science and Engineering

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2015

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Vol. 74, nr 1

32--44

EN

Purpose: The purpose of the work is to examine the influence of carbon nanotubes on the properties of dye-sensitised solar cells. Design/methodology/approach: The research material consisted of samples of glass plates with a conductive layer of FTO onto which layers were subsequently deposited of TiO2 titanium dioxide and titanium dioxide with an absorbed dye, a high conductivity PEDOT:PSS polymer with multi-walled carbon nanotubes, carbon black and graphite. Findings: The application of carbon nanotubes as one of electrodes in a dye-sensitised solar cell is significantly improving the effectiveness of the dye-sensitised solar cell being manufactured. Research limitations/implications: Carbon nanotubes are a good potential material for optoelectronics and photovoltaics. Practical implications: Carbon nanotube electrodes feature high conductivity and high visible light transmission. Originality/value: It is possible to change a structure of a dye-sensitised solar cell by replacing the commonly used platinum in a counter electrode with another electrode permeable for visible light made of a high conductivity PEDOT:PSS polymer with multi-walled carbon nanotubes.

6

Barwnikowe ogniwa słoneczne z przeciwelektrodą grafenową

Klein M., Siuzdak K., Cenian A.

Polska Energetyka Słoneczna

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2014

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nr 1-4

5--9

PL

W niniejszej pracy przedstawiono technologię barwnikowych ogniw słonecznych wykorzystujących jako przeciwelektrodę (katodę) warstwę nanopłatków grafenowych wytworzoną metodą pokrywania natryskowego. Mimo gorszych wartości parametrów ogniwa z warstwą węglową w porównaniu do ogniwa z warstwą Pt, konkurencyjna cena grafenu w stosunku do platyny oraz możliwość poprawy wydajności ogniwa poprzez kontrolę parametrów wytwarzania warstw otwiera szerokie perspektywy dla zastąpienia metalu szlachetnego - materiałem węglowym.

7

Counter electrodes for WO/sub 3/-based electrochromic coatings

Żelazowska E., Ziemba B., Lachman W.

Optica Applicata

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2000

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Vol. 30, nr 4

663-670

EN

Thin polycrystalline electrochromic tungsten trioxide as well as nickel, vanadium and titanium oxide films with and without lithium additive were prepared by spray pyrolysis on glass coated with SnO/sub 2/:F, using acetylacetonates as precursor materials. The substrate temperature was held at 600 degrees C for WO/sub 3/ and 680 degrees C for the other metal oxide films. Electrochromic colouration and bleaching characteristics were examined in the transmissive electrochromic cell arrangement, using LiClO/sub 4/-poly(ethylene oxide) polymer electrolyte and significant changes of optical transmission in the visible and solar range, up to 70%, were observed. The obtained films were electrochemically stable and colouration and bleaching cycles were reversible at a voltage of +or-(1-25) V. The start of the electrochemical reactions for most of the films obtained was observed in the range of +or-(0.3-4) V.