TCO Glass Research Articles

Performance Degradation Model of Dye-Sensitized Solar Cell (DSSC) Using Dye Extracted from Red Dragon Fruit’s Flesh

This paper reports on the fabrication and characterization of dye-sensitized solar cell (DSSC) which utilizes dye extracted from local red dragon fruit’s flesh. The DSSC was hand-made using doctor blade method on single-sided ITO-coated TCO glass with iodine solution as the liquid charge transporter and dye infiltrated mesoporous layer made from paste of TiO2 nanoparticles powder and acetic acid. The fabricated samples were tested using an own-made solar simulator with 85 W 12 V halogen light source and measured for I-V curve using a home-made Arduino-based automated I-V measurement tool. The experiments gave best results for DSSC which used a paste composed of 1 gr of TiO2 nanoparticle powder and 3.2 ml of 15% acetic acid soaked in dye for 90 mins. The results show that a cell of 21 mm x 21 mm has open circuit voltage (V oc) of 459.28 mV, short circuit current (I sc) of 10.14μA, fill factor (FF) of 55.39% and conversion efficiency (η) at maximum power point (MPP) of 0.0088% at 30 minutes post assembling under exposure to 66.7 W/m2 irradiation. The DSSC degraded over time and fitted well to a two-parameter model equation. Compared to similar cell fabricated using dye taken from blackberry fruit, which exhibited η = 0.0133%, the cell with dye of red dragon fruit’s performance is worse.

Electroactive Electrodeposited Platinum Nanoparticles and Platinum NPs/Graphite Electrodes for Photovoltaic Application

In this work, electroplating is used to deposit platinum nanoparticles (Pt NPs) on a transparent conductive oxide substrate (TCO glass) as an alternative simple and low-cost technique compared to sputtering. The used platinum salt is cost effective, and a general purpose grade can be used for large-scale manufacturing. In order to study the effects of deposition method of platinum on the electrode performance, two electrochemical deposition techniques are investigated (chronoamperometry and cyclic voltammetery) to deposit platinum using the same initial materials. Also, the effect of modifying the platinum counter electrode surface by deposition of a graphite thin layer by simple technique was investigated. Finally, Pt(NPs) and Pt(NPs)/graphite electrodes were used to assemble dye sensitized solar cells (DSSCs), and the cell with structure [TCO/TiO2/N719 Ru dye/electrolyte I3/I− redox/platinum NPs/graphite/TCO] yields output photovoltaic parameters of open circuit voltage, current density, fill factor and the highest efficiency with values of 0.65 V, 29.2 mA/cm2, 0.41, 7.9%, respectively.

Carbon Nanomaterials Application as a Counter Electrode for Dye-Sensitized Solar Cells

AbstractThe paper presents the results of the structure investigation of a counter electrode in dye-sensitized solar cells using the carbon nanomaterials. Solar cells were fabricated on the glass with transparent conductive oxide TCO (10Ω/sq). Nanocrystalline titania based photoanode was prepared by spreading TiO2paste onto TCO glass and subsequently annealed at 450°C for at least 30 min to convert anatase phase and make an interparticle network. After then the nanostructured titania films was immersed into an ethanolic solution of the ruthenium-based dye. As a counter electrodes of dye-sensitized solar cells composite films of carbon nanomaterials and polystyrene sulfonate doped poly (3,4-ethylenedioxythiophene) PEDOT-PSS (Sigma-Aldrich) were deposited onto TCO substrates. Because carbon nanoelements and titanium oxide consist of nano-metric structural units to determine the properties of the cells and their parameters several surface sensitive techniques and methods, i.e. Raman spectroscopy, Scanning Electron Microscopy (SEM), High-Resolution Transmission Electron Microscopy (HRTEM), and electric properties of conductive layers were used.

Optical Properties and Electrochemical Performance of LiFePO4 Thin Films Deposited on Transparent Current Collectors.

LiFePO4 thin film cathodes are deposited on various transparent conducting oxide thin films on glass, which are used as cathode current collectors. The XRD patterns show that the thin films have the phase of LiFePO4 with an ordered olivine structure indexed to the orthorhombic Pmna space group. LiFePO4 thin film deposited on various TCO glass substrates exhibits transmittance of about 53%. The initial specific discharge capacities of LiFePO4 thin films are 25.0 μAh/cm2 x μm on FTO, 33.0 μAh/cm2 x μm on ITO, and 13.0 μAh/cm2 x μm on AZO coated glass substrates. Interestingly, the retention capacities of LiFePO4 thin films are 76.0% on FTO, 31.2% on ITO, and 37.7% on AZO coated glass substrates at 20th cycle. The initial specific discharge capacity of the LiFePO4/FTO electrode is slightly lower, but the discharge capacities of the LiFePO4/FTO electrode relatively decrease less than those of the others such as LiFePO4/ITO and LiFePO4/AZO with cycling. The results reported here provide the high transparency of LiFePO4 thin films cathode materials and the good candidate as FTO current collector of the LiFePO4 thin film cathode of transparent thin film rechargeable batteries due to its high transparency and cyclic retention.

Recyclable electrochemical allylation in aqueous ZnCl2medium: synthesis and reactivity of a wire-shaped nano zinc architecture

Electrochemistry is used in an aqueous allylation reaction using zinc chloride as the reagent. A unit galvanic cell using a beaker containing an aqueous zinc chloride solution, zinc rod, TCO glass plate and connecting copper wire has been designed. Instead of using a connecting copper wire, an external bias can be used for applying voltage from the outside. The zinc rod served as a self-decaying anode and the TCO glass substrate as the cathode. During the process, a wire-shaped nano zinc architecture was formed from zinc chloride on the cathode. Wire-shaped nano zinc is the active reagent for the allylation of aldehydes or imines. The corresponding homoallylic alcohols or amines are prepared in good yields. Both the zinc salts and water can be recycled.

An innovative photoelectrochemical lab device for solar water splitting

A photoelectrochemical (PEC) device capable of splitting water into storable hydrogen fuel by the direct use of solar energy is becoming a very attractive technology since it is clean and sustainable. Indeed, real field experiments are being developed in order to assess technological issues for large-scale usage under outdoor conditions. Following the need for developing photoelectrochemical devices with an optimized design that allows reaching a commercial performance level, the present works describes an innovative PEC cell for testing different photoelectrodes configurations, suitable for continuous operation and for easily collect the evolved gases. Moreover, a porous Teflon® diaphragm useable for a wide range of aqueous electrolyte solutions is tested. Two semiconductors were investigated: tungsten trioxide and undoped hematite. The WO3 photoelectrodes were deposited in two different substrates: (i) anodized WO3 photoelectrodes on a metal substrate and (ii) WO3 deposited by blade spreading method on a TCO glass substrate. The undoped-Fe2O3 photoanode was deposited by ultrasonic spray pyrolysis technique in a TCO glass substrate. The material deposited on glass substrates allows to obtain transparent photoelectrodes. Photocurrent–voltage characteristics were obtained for all samples characterized under three different conditions: (i) no membrane separating the anode and the cathode evolution; (ii) using a Teflon® diaphragm and (iii) using a Nafion® 212 membrane. The transparent samples (photoanodes deposited on glass substrates) produced the highest values of photocurrent when the Teflon® diaphragm was used. This photocurrent enhancement was assigned to the high reflectance showed by the diaphragm, which reflects back a significant fraction of the transmitted solar radiation.

The Effects of Varied Deposition Conditions, Including the Use of Argon, on Thin-Film Silicon Solar Cells Prepared using PECVD

This paper reports the effects of varied deposition conditions on the resultant energy conversion efficiencies of thin-film silicon solar cells. Cells were deposited using an Oxford Instruments PlasmaLab System 100 on to Pilkington TEC-8 TCO glass, and thoroughly investigated using electrical methods. Thin film devices were fabricated using the decomposition of silane gas within a reaction chamber of 13.56 MHz plasma discharge. The deposition conditions, including substrate temperature, gas flow rates, RF power, chamber pressure, and film thickness are all explored to determine the optimum cell performance. A view toward high-efficiency solar structures, including heterojunction with intrinsic thin layer (HIT) and micro-morph cell designs using the same conditions is presented.

Fabrication and Characterization of CuInS<sub>2</sub><sub> </sub>Sensitized TiO<sub>2 </sub>Electrodes Based on Improved SILAR Process

CuInS2quantum dots have been deposited onto mesoporous TiO2films on TCO glass substrate via successive ionic layer absorption and reaction process (SILAR) by using three different routes and post-deposition annealing in sulfur ambiance. The influence of the deposition sequence of the In-S and Cu-S on the microstructure of CuInS2sensitized TiO2electrodes and the photovoltaic performance of the solar cells have been investigated. The microstructure of CuInS2sensitized TiO2electrodes has been investigated by using X-ray diffraction (XRD), Raman spectra, scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) analysis. The optical absorption property of the electrodes has been detected by using UV-Vis spectroscopy, and the photovoltaic performance of CuInS2quantum dots sensitized solar cells has been determined by cyclic voltammetry measurement. It has been found that when the Cu-S was deposited prior to In-S, the chalcopyrite phase CuInS2could not be observed due to the sublimation of InxS during the annealing under low pressure. A small amount of CuInS2has been detected when In-S and Cu-S was deposited alternately onto the TiO2films. However, chalcopyrite phase CuInS2can be obtained when In-S was deposited prior to Cu-S, and a relative high efficiency of ca. 0.92% (Voc= 0.35V, Jsc= 8.49 mA·cm-2, FF = 0.31) has been achieved via SILAR without KCN treatment and rapid thermal annealing.

Effective charge collection in dye-sensitized nanocrystalline TiO2

The effective charge collection in dye-sensitized solar cells (DSCs) is an important factor to improve the efficiency. Here, we report the comparison of three types of structures in DSCs. One type of structure is a sandwich-type DSC (SW-DSC), in which the TiO2 film is sandwiched between a TCO glass front electron-collection electrode and a sputtered Ti back collection electrode. The second is a normal DSC (N-DSC), which has no back electrode. The third is a back-contact-type DSC (BC-DSC), in which a sputtered Ti back electrode is deposited on a TiO2 film on the opposite side of the normal glass as an optical window. The photocurrent response of an SW-DSC is the fastest of the three structures due to using intensity modulated photocurrent spectroscopy, which can be explained by the electron diffusion model. The model shows that the SW-DSC is a favorable structure for effective charge collection in DSCs.

Modification of the picosecond optical absorptive nonlinearity by a nanosecond irradiation in a nanostructured ZnO thin film

Nanostructured ZnO thin solid films were synthesized by electrodeposition of hydrothermal sol–gel solutions on TCO glass. A strong enhancement in the absorptive and refractive nonlinear optical response of the sample was obtained by means of an annealing process at the end of the preparation method. A simple configuration for generating an increment in the optical transmittance of the sample with different optical irradiations was proposed. The nonlinear optical measurements were performed using the Z-scan technique with picosecond pulses and a transmittance experiment with nanosecond pulses. Picosecond results indicated an important electronic refractive nonlinearity exhibited as a self-focusing effect; whereas for nanosecond pulses, a dominant nonlinear optical response was responsible for the third order nonlinearity. In both temporal regimes a saturable absorption was identified as the main physical mechanism of nonlinear optical absorption; however strong differences in the magnitude of this phenomenon were observed. A physical explanation based on a two-level system was evoked to describe the irradiance conditions whereby the optical nonlinearities were manifested for each case. Potential applications for developing all-optical switching devices were contemplated.

Utilization of geometric light trapping in thin film silicon solar cells: simulations and experiments

ABSTRACTIn this study, we present a new light absorption enhancement method for p‐i‐n thin film silicon solar cells using pyramidal surface structures, larger than the wavelength of visible light. Calculations show a maximum possible current enhancement of 45% compared with cells on a flat substrate. We deposited amorphous silicon (a‐Si) thin film solar cells directly onto periodically pyramidal‐structured polycarbonate (PC) substrates, which show a significant increase (30%) in short‐circuit current over reference cells deposited on flat glass substrates. The current of the cells on our pyramidal structures on PC is only slightly lower than that of cells on Asahi U‐type TCO glass (Asahi Glass Co., Tokyo, Japan), but suffer from a somewhat lower open circuit voltage and fill factor. Because the used substrates have a locally flat surface area due to the fabrication process, we believe that the current enhancement in the cells on structured PC can be increased using larger or more closely spaced pyramids, which can have a smaller flat surface area. Copyright © 2012 John Wiley & Sons, Ltd.

Structure of electron collection electrode in dye-sensitized nanocrystalline TiO2

As part of the effort to control electron transport in the TiO2 films of dye-sensitized solar cells (DSCs), the structure of the electron collection electrode on the films has been investigated. Here, we report the comparison between a sandwich-type dye-sensitized solar cell (SW-DSC), in which the TiO2 film is sandwiched between a TCO glass front electron collection electrode and a sputtered Ti back charge collection electrode, and a normal DSC (N-DSC), which has no back electrode. In N-DSCs, electrons in TiO2 that are far from the front electrode have to diffuse for a long distance (ca. 10μm), and therefore, the photocurrent cannot rapidly respond to light with a modulation frequency >100Hz. In SW-DSCs, the photocurrent response was enhanced at frequencies between 10 and 500Hz because electrons in TiO2 can be extracted by both front and back electrodes, which can be also explained by an electron diffusion model. Calculations based on the electron diffusion model suggested that a high short-circuit photocurrent could be maintained in SW-DSCs even when the electron diffusion length in the TiO2 film was shortened.

Scattering, Diffraction, and Geometric Light Trapping in Thin Film Amorphous Silicon Solar Cells on Plastic Substrates

ABSTRACTIn this study we compare light trapping in hydrogenated amorphous silicon (a-Si:H) solar cells deposited directly onto polycarbonate (PC) at low temperature (< 130°C). To that end, we embossed PC substrates with 400 nm and 10 μm square based pyramids to induce light trapping based on diffraction and on geometric effects. As a comparison, we deposited a-Si:H cells on flat glass substrates and on Asahi U-type TCO glass. The cells on PC generate current densities comparable (slightly higher) than cells on Asahi TCO glass, but suffer from a slightly lower Voc, resulting in cells with an initial efficiency of 6.8% and 7.4% on sub-micron pyramid and micro-pyramid structured PC substrates respectively, compared to 7.6% for cells on Asahi. This shows great potential for a-Si:H cells deposited directly onto cheap plastics.

Platinum Nanoparticles on Flexible Carbon Fiber Paper without Transparent Conducting Oxide Glass as Counter Electrode for Dye‐Sensitized Solar Cells

AbstractFlexible carbon fiber paper deposited with platinum nanoparticles was applied as counter electrode for dye‐sensitized solar cells (DSSCs). Compared to others, such as sputtered‐Pt or PVP‐capped Pt nanoparticles on TCO glass, not only does this counter electrode has good conductivity without using TCO glass but also flexible and shows good adhesion. Acceptable charge‐transfer resistance of 5.25 Ω‐cm2 is obtained. Current‐voltage characteristics of the DSSC are 0.71 V on VOC, 9.44 mA/cm2 on JSC, 0.61 on FF and 4.13% cell efficiency under AM 1.5, 100 mW/cm2 illumination. Additionally, spinning technology can be applied to produce this low cost counter electrode.

Leistungsfähige Dünnschicht-Beschichtung für die Photovoltaik

High-performance thin-film coating for photovoltaic applications The thin-film photovoltaics market is large and is expected to grow continuously. Due to its huge potential regarding cost reduction and cell efficiency improvement, sputter-etched ZnO:Al-based TCO can make a sustainable contribution to achieve grid parity. One of the most promising approaches here is the large scale volume manufacturing of sputter-etched TCO glass for thin film silicon solar cells. VON ARDENNE's leading process knowhow, applied to the highly productive and reliable PIA|nova coating system, allows for cost effective production and flexible adaptation of customer specific TCO requirements.

The simple and easy way to manufacture counter electrode for dye-sensitized solar cells

We previously developed poly-N-vinyl-2-pyrrolidone (PVP)-capped Pt nanoclusters on ITO glass via a simple “2-step dip coating process” as counter electrode for DSSC. This new counter electrode was examined by transmission electron microscopy (TEM), inductively coupled plasma-atomic emission spectroscopy (ICP-AES), electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and current–voltage curve ( I– V curve). The TEM results revealed that PVP-capped Pt nanoclusters’ size is about 3 nm, and the amount of Pt deposited on ITO glass is about 5 μg/cm 2. Comparing with sputtered Pt and Solaronix thermal cluster Pt-catalyst T/SP, the PVP-capped Pt counter electrode has lower amount of Pt deposited on TCO glass, more positive potential of tri-iodide reduction, and better performance for the charge-transfer resistance ( R CT) and the cell efficiency ( η).

Enhanced Photoelectrochemical Activity of 120 MeV Ag<sup>9+</sup> Irradiated Nanostructured Thin Films of ZnO for Solar-Hydrogen Generation via Splitting of Water

This paper deals with a study on 120 MeV Ag9+ irradiated thin films of zinc oxide (ZnO), obtained by sol-gel – spin coating onto TCO glass plates. Films irradiated at fluence 5×1011, 3×1012, 5×1012 and 2×1013 ions cm-2, were optically characterized for band gap determination. XRD analysis revealed polytypism as both wurtzite and zincblend phases co-evolved. Scherrer’s calculations indicated grain size in nanodimensions, while SEM analysis indicated smooth surface morphology of films. Flat band potentials and donor densities were evaluated by Mott-schottky calculations. For PEC studies, thin films of ZnO were employed as working electrode in conjunction with Platinum Counter electrode, Saturated Calomel Reference electrode, 13 pH aqueous solution of NaOH as electrolyte and 150W Xenon Arc light source for illumination. A significant gain in photoelectrochemical current was recorded on SHI irradiation. The films irradiated at fluence 3×1012 ions cm-2 yielded maximum increase in photocurrent that was nearly five times compared to unirradiated samples.

The growth of CuS thin films by Spray Pyrolysis

Thin films of CuS (covellite) were deposited onto TCO (SnO2:F) glass by Spray Pyrolysis (SP) technique. Aqueous and water:alcohol (ethanol, 1-propanol) solutions of copper(II) chloride and thiourea with different Cu/S molar ratio have been used as precursors. The substrate temperature was varied from 185 °C to 285 °C. The structural and the morphological characterization of the films has been carried out by Raman spectroscopy and Scanning Electron Microscopy. The X-Ray Diffraction analysis of as-grown films showed the single-phase covellite, with hexagonal crystal structure built around three preferred orientations corresponding to (102), (103) and (110) atomic planes. The dense morphology of CuS films with large crystallites/aggregates suggest that crystal growth is the limiting step in the films deposition, at 235 °C and at 285 °C, from precursors' solution containing water or mixtures of water:alcohol as solvents. The growth of CuS thin films by spray pyrolysis is favored by increasing both the alcohol concentration and the deposition temperature.

Five Strip-Type Dye Sensitized Solar Cells with Metal Grid Lines

Dye sensitized solar cells (DSSC) have great potential alternative to expensive conventional solar cells, since high efficiency and relatively simple fabrication process. However, in large size cell, there is a key factor that delayed the entry of such cells in commercial market. Performance of large size cell is lower than small size cells, since a carrier loss occurs in high resistive TCO glass substrate. Here we demonstrate a simple method to reduce resistive loss and efficient collection of photo generated carriers via strip type cells with metal grids. Using strip type cells, we constitute series and parallel type DSSC panels in order to achieve required voltage and current respectively. Stripe cells were prepared from commercial TiO2 powder by screen printing method. In addition, metal grids were established adjacent to sealant line. Using these as unit cell, portable DSSC panels were assembled and I-V performance was carried out in indoor light condition (fluorescent light, 30mW/cm2) and standard condition (Pin 100 mW/cm2, AM 1.5).

Optimization of photoelectrode introduced to dye-sensitized solar cells by anodic oxidative hydrolysis

The influence of three different modification methods on the photoelectrode introduced to dye-sensitized solar cells by anodic oxidative hydrolysis of acidic aqueous TiCl3 solutions was investigated. X-ray diffraction analysis shows that the nanocrystalline TiO2 prepared by sol-gel and electrodeposition is anatase. The average nanocrystalline size of TiO2 prepared by electrodeposition is 19nm and that by sol-gel method is 23.7nm. The surface structure of the nanoporous TiO2 films and TCO glass are observed by field-emission scanning electron microscopy before and after electrodeposition. It is found that the short-current density and the photoelectric conversion efficiency of dye-sensitized solar cells are improved a lot through these different methods.