Dye-Sensitized Nanocrystalline Solar Cells Employing a Polymer Electrolyte (original) (raw)
Related papers
Photochemical solar cells based on dye-sensitization of nanocrystalline TiO/sub 2/
Conference Record of the Twenty Sixth IEEE Photovoltaic Specialists Conference - 1997, 1997
A new type of photovoltaic cell is described. It is a photoelectrochemical device that is based on the dyesensitization of thin (10-20 µm) nanocrystalline films of TiO 2 nanoparticles in contact with a non-aqueous liquid electrolyte. The cell is very simple to fabricate and, in principle, its color can be tuned through the visible spectrum, ranging from being completely transparent to black opaque by changing the absorption characteristics of the dye. The highest present efficiency of the dye-sensitized photochemical solar cell is about 11%. The cell has the potential to be a low-cost photovoltaic option. Unique applications include photovoltaic power windows and photoelectrochromic windows.
Sinet Ethiopian Journal of Science, 2012
A solid state photoelectrochemical solar energy conversion device based on nanocrystalline-TiO 2 sensitized with Di-Tetrabutylammoniumcis-bis(isothiocyanato)bis(2,2'bipyridyl-4,4'-dicarboxylato)-ruthenium(II) (N719) dye has been constructed and characterized. The current density-voltage characteristics in the dark and under white light illumination and action spectra under monochromatic illuminations have been studied. The following device parameters were obtained when the potential is scanned: an open circuit voltage of 762 mV and a short circuit current density of 33 μAcm-2 at light intensity of 100 mWcm-2 ; the IPCE percentage obtained was 1.7% at 330 nm. The dependence of the short-circuit current density and an open circuit voltage on the incident light intensity and illumination time have also been studied. The results of time dependence study show that the steady state J sc and V oc values are consistent with those obtained from the J-V curve.
Electron Transfer Dynamics in Dye Sensitized Nanocrystalline Solar Cells Using a Polymer Electrolyte
The Journal of Physical Chemistry B, 2001
Transient absorption spectroscopy was employed to study electron-transfer dynamics in dye sensitized nanocrystalline solar cells incorporating a polymer electrolyte, poly(epichlorohydrin-co-ethylene oxide) containing NaI and I 2. Solar cells employing this solid-state electrolyte have yielded solar to electrical energy conversion efficiencies of up to 2.6%. Electron-transfer kinetics were collected as a function of electrolyte composition, white light illumination, and device voltage and correlated with current/voltage characterization of the cell. The yield of electron injection from the dye excited state into the TiO 2 electrode was found to be insensitive to electrolyte composition or cell operating conditions. Regeneration of the dye ground state by electron transfer from Iions in the polymer electrolyte exhibited half times of 4-200 µs, depending upon the concentration of NaI in the polymer electrolyte. A long-lived product of the regeneration reaction was observed and assigned to the I 2radical. At low NaI concentrations, kinetic competition was observed between this regeneration reaction and charge recombination of the oxidized dye with electrons injected into the semiconductor. The decay kinetics of the dye cation, and the yield of I 2-, were found to be unchanged by illumination of the cell under either short circuit or open circuit (V oc) 0.75 V) conditions. From these observations, we conclude that the charge recombination dynamics in this cell are not strongly dependent upon the TiO 2 Fermi level over this voltage range. Analogy with studies of recombination dynamics in three electrode photoelectrochemical cells employing a redox inactive liquid electrolyte suggest this observation may be related to the Lewis base nature of the polymer employed.
Research & Reviews: Journal of Material Sciences
The world is now shifting from the conventional energy sources to renewable energy to meet the energy demand. Among the sustainable technologies, photovoltaic technology is regarded as the most efficient [1]. It is based on the concept of charge separation at an interface of two materials of different conduction mechanism [2]. Dye sensitized solar cells (DSSCs) have received considerable attention and a remarkable high conversion energy efficiency of nearly 10% using crystalline mesoporous TiO 2 film [3] , in which the optical absorption and charge separation takes place. The assembly of a dye-sensitized solar cell is based on a layered structure, which consists of two transparent glass plates with a Transparent Conductive Oxide (TCO) on it, placed parallel to each other and spaced of about 40 μm apart. On one of the plates is applied a nanocrystalline TiO 2 layer coated organometallic photosensitive dye-this collection, retrieve in the cell function photo-anode (illuminated anode). The surface of the other glass ABSTRACT Dye-sensitized solar cells (DSSCs) have gained widespread attention in recent years because of their low production cost, ease fabrication and tunable optical properties, such as colour and transparency. Now-a-days natural dye was used to sensitize the electrode and the counter electrode was prepared by the help of carbon black. In this study we report molecularly engineered different dyes (henna, pomegranate and beet root) and nanoTiO 2 in the DSSCs, which features the prototypical structure of a donor-π-bridge-acceptor and maximizes electrolyte compatibility with improved light-harvesting properties. BulkTiO 2 of sizes 150 micron were converted to nanoTiO 2 particles having sizes less than 20 nm using planetary ball mill. Our design consists of a lattice of modulated-diameter nanoTiO 2 particles and interstitial regions filled with electrolyte. This provides not only light trapping and absorption enhancement, but offers improved electrical transport through the nanoTiO 2 particles. It is observed that when frequency increases both capacitance and resistance decreases. At certain point capacitance it maintains a steady state and resistance is nearly equal to zero. This is due to the internal resistance and the steady state capacitance of the cell. It conforms that the fabricated dye sensitized solar cell works like a conventional cell. It is found that henna and pomegranate dyes shows better energy conversion efficiency than beet root dye.
Anatase phase containing nano-crystallite TiO 2 thin film is prepared by the peptization of modified Ti-isopropoxide sol using HNO 3 as peptizing agent. The resulting sol is concentrated in a rotary evaporator bath. TiO 2 film is deposited on ITO substrate by spin coating process. The compact film is annealed at 450˚C and 500˚C for optical studies. The subsequently it is modified as photo-anodes in dye sensitized solar cells. The prepared materials are characterized by X-ray diffraction (XRD), UV-Vis absorption spectroscopy and high resolution transmission electron microscopy (HRTEM). The colloidal particles are 6-8nm in average size while the grain growth of the particles are in the order of 13-20nm after annealing of the thin film. The obtained lattice constants of the TiO 2 nanocrystals are a=3.79Å and c=9.48Å from XRD data as compared to JCPDS data of a=3.79Å and c=9.52Å. The photo conversion efficiency of assembled dye sensitized solar cells comprising of ~5µm thickness of the film are determined to be of the order of 6.77%.
Journal of Materials Chemistry, 2011
We demonstrate a general approach by which colloidal anatase TiO 2 nanocrystals with anisotropically tailored linear and branched shapes can safely be processed into high-quality mesoporous photoelectrodes for dye-sensitized solar cells (DSSCs). A detailed study has been carried out to elucidate how the nanoscale architecture underlying the photoelectrodes impacts their ultimate performances. From the analysis of the most relevant electrochemical parameters, an intrinsic correlation between the photovoltaic performances and the structure of the nanocrystal building blocks has been deduced and explained on the basis of relative contributions of the electron transport and light-harvesting properties of the photoelectrodes. Depending on the nanocrystals incorporated, these devices can exhibit an energy conversion efficiency of 5.2% to 7.8%, which ranks 38% to 53% higher than that achievable with corresponding cells based on reference spherical nanoparticles. It has been ascertained that DSSCs based on high aspect-ratio linear nanorods allow for a remarkable improvement in the charge-collection efficiency due to minimization of detrimental chargerecombination processes at the photoelectrode/electrolyte interface. On the other hand, DSSCs fabricated from branched nanocrystals with a peculiar bundle-like configuration are characterized by a drastic reduction of undesired charge-trapping phenomena. These findings can be useful in the design and fabrication of future generations of high-performing DSSCs based on colloidal nanocrystals with properly engineered size and shape parameters. † Electronic supplementary information (ESI) available: TEM images of the reference spherical nanocrystals; SEM images showing the morphology of an AR16-NR-based photoelectrode prepared by deposition of a conventional screen-printable paste; SEM images showing the morphology of the sintered films prepared from spherical TiO 2 nanocrystals; and cross-section SEM images showing the morphology of the sintered films. See
Dye-sensitized photoelectrochemical solar cells based on nanocomposite organic–inorganic materials
Journal of Photochemistry and Photobiology A: Chemistry, 2005
Dye-sensitized photoelectrochemical solar cells have been constructed by using nanocomposite organic-inorganic sol-gel electrolytes and a titania nanocrystalline film also based on a sol-gel nanocomposite material. Among other advantages connected with nanocomposite electrolytes is the balance between hydrophilic and hydrophobic domains that allows reducing polarity-connected repulsive forces developing between the titania-dye system and the electrolyte. The overall efficiencies of these cells range between 5 and 6% under 100 mW/cm 2 illumination (equivalent to 1 sun at AM1.5).