Effect of polyaniline (PANI) on efficiency enhancement of dye-sensitized solar cells fabricated with poly(ethylene oxide)-based gel polymer electrolytes

Journal of Solid State Electrochemistry - Ionically conducting gel polymer electrolytes can be used effectively to improve the problems associated with liquid electrolytes in dye-sensitized solar...     

Advanced composite gel electrolytes prepared with titania nanotube fillers in polyethylene glycol for the solid-state dye-sensitized solar cell

A novel inorganic–organic composite solid electrolyte is prepared by using TiO₂ nanotubes (TiNTs) as filler in polyethylene glycol (PEG) and effectively used for the fabrication of solid-state dye-sensitized solar cells (DSSCs). Comparably high conversion efficiency 4.43% has been observed by using the newly designed inorganic–organic (PEG–TiNTs) composite solid electrolyte. By performing several experiments by using PEG–TiNTs composite solid electrolytes, it was observed that the appropriate ratios of TiNTs and PEG are important to obtain higher conversion efficiency. Moreover, the morphologies, chemical interactions of PEG and TiNTs and their performance to the DSSCs are studied extensively by FESEM, DSC, and XPS measurements.     

Solidifying liquid electrolytes with fluorine polymer and silica nanoparticles for quasi-solid dye-sensitized solar cells

Poly(vinylidenefluoride-co-hexafluoropropylene) (PVDF-HFP) and silica nanoparticles were employed to solidify 3-methoxypropionitrile based liquid electrolytes containing an ionic liquid, 1-methyl-3-propylimidazolium iodide, as iodide resource. These new quasi-solid-state electrolytes were successfully used for regenerative phtoelectrochemical cells that yielded about 6.7% efficiency under simulated full sunlight (air mass 1.5, 100 mW cm⁻²) in combination with an amphiphilic ruthenium polypyridyl photosensitizer. The as-fabricated device showed a good thermostability at 80 °C for 30 days, maintaining higher than 90% of its initial performance.     

Liquid electrolytes for dye-sensitized solar cells

The present review offers a survey of liquid electrolytes used in dye-sensitized solar cells from the beginning of photoelectrochemical cell research. It handles both the solvents employed, and the prerequisites identified for an ideal liquid solvent, as well as the various effects of electrolyte solutes in terms of redox systems and additives. The conclusions of the present review call for more detailed molecular insight into the electrolyte-electrode interface reactions and structures.     

Quasi solid-state quantum dot–sensitized solar cells with polysulfide gel polymer electrolyte for superior stability

Journal of Solid State Electrochemistry - In the case of sensitized solar cells, liquid electrolyte materials are the fundamental components due to its advantage of superior conductivity. However,...     

Ionic liquid electrolytes for dye-sensitized solar cells

The potential of room-temperature molten salts (ionic liquids) as solvents for electrolytes for dye-sensitized solar cells has been investigated during the last decade. The non-volatility, good solvent properties and high electrochemical stability of ionic liquids make them attractive solvents in contrast to volatile organic solvents. Despite this, the relatively high viscosity of ionic liquids leads to mass-transport limitations. Here we review recent developments in the application of different ionic liquids as solvents or components of liquid and quasi-solid electrolytes for dye-sensitized solar cells.     

Ionic liquid integrated polyethylene glycol (PEG)-based quasi-solid electrolyte for efficiency enhancement of dye-sensitized solar cell

Journal of Solid State Electrochemistry - We are presenting herein the effect of using three different cell electrolytes namely: (a) propylene carbonate containing 0.2 M LiI and...     

High performance dye-sensitized solar cell based on 2-mercaptobenzimidazole doped poly(vinylidinefluoride-co-hexafluoropropylene) based polymer electrolyte

In this work, the influence of 2-mercaptobenzimidazole (2-MCBI) on poly(vinylidinefluoride-co-hexafluoropropylene)/KI/I₂ (PVDF-HFP/KI/I₂) polymer electrolytes were studied. The pure and different weight percentage ratios (20, 30, 40 and 50%) of 2-MCBI doped PVDF-HFP/KI/I₂ electrolytes were prepared by a solution casting technique. The as-prepared polymer electrolyte films were characterized using various techniques such as Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC), X-ray diffractometer (XRD), alternating current (AC)-impedance analysis. The addition of 2-MCBI with pure PVDF-HFP/KI/I₂ was found to increase the ionic conductivity of electrolyte. Among the various additions, 30 wt% 2-MCBI doped PVDF-HFP/KI/I₂ showed the highest room temperature ionic conductivity values than the others. The dye-sensitized solar cell (DSSC) fabricated using this optimized polymer electrolyte achieved a high power conversion efficiency of 4.40% than the pure PVDF-HFP/KI/I₂ (1.74%) at similar experimental conditions. Thus, the 2-MCBI doped polymer electrolyte has proven to be an effective substitute to the liquid electrolyte in DSSCs.     

Preparation of poly(ether ether ketone)-based polymer electrolytes for fuel cell membranes using grafting technique

Poly(ether ether ketone) (PEEK)-based polymer electrolyte membranes (PEMs) was successfully prepared by radiation grafting of a styrene monomer into PEEK films and the consequent selective sulfonation of the grafting chains in the film state. Using milder sulfonation, the sulfonation reactions proceeded at the grafted chains in preference to the phenylene rings of PEEK main chains; as a result, the grafted films could successfully transform to a PEM with conductivity of more than 0.1 S/cm. The ion exchange capacity (IEC) and conductivity of the grafted PEEK electrolyte membranes were controlled to the ranges of 1.2–2.9 mmol/g and 0.03–0.18 S/cm by changing the grafting degree. It should be noted that this is the first example of directly transforming super-engineering plastic films into a PEM using radiation grafting.     

Dithienothiophene (DTT)-based dyes for dye-sensitized solar cells: synthesis of 2,6-dibromo-DTT

A one-pot synthesis of 2,6-dibromodithieno[3,2-b;2',3'-d]thiophene (dibromo-DTT, 4) was developed. A key step was bromodecarboxylation of DTT-2,6-dicarboxylic acid, obtained by saponification of the diester 1. The donor-acceptor dye DAHTDTT (13), based on a central 2,6-bis[2'-(3'-hexylthienyl)]dithieno[3,2-b;2',3'-d]thiophene core (9), was prepared and incorporated in a dye-sensitized solar cell (DSC), which exhibited an energy conversion efficiency of 7.3% with V(oc) of 697 mV, J(sc) of 14.4 mA/cm(2), and ff of 0.73 at 1 sun.     

A new study on solid-state cyanine dye-sensitized solar cells

A new cyanine dye, 7-{1-[2-(4-morpholine-1,8-naphthalimide)ethyl]-1H-1,2,3-triazol-4-}-2-[3-(5-carboxyl-1,3-dihydro-3,3-dimethyl-1-butyl-indolin-2-methylene)-propenyl]-1,1-dimethyl-3-buty-1H-benzo[e]indolium iodide (BIDC), has been synthesized and identified with regard to its structure and photoelectrochemical properties used as a sensitizer on dye-sensitized solar cells. A novel solid-state electrolyte with polyaniline-loaded carbon black (PACB)-1-methyl-3-propylimidazolium iodide (MPII) composite was investigated on these dye-sensitized solar cells (DSCs). The short-circuit photocurrent density (J _sc), open-circuit photovoltage (V _oc) and fill factor (ff) under 200 W/m² white light from a xenon lamp are 0.44 mA/cm², 550 mV and 0.58, respectively, yielding an overall conversion efficiency (η) of 0.7%. The most merit of the solid-sate electrolyte was free of volatile and flammable fluid components and easy of encapsulation for DSCs.     

Investigation of the stability of solid-state dye-sensitized solar cells

The stability of the TiO₂/ruthenium dye/CuI solid-state solar cell was investigated under continuous simulated sunlight illumination. The cells showed fast degradation under full-spectrum sunlight illumination, but showed rather good stability when the ultraviolet part of the illumination was removed. XPS measurements showed evidence that TiO₂ could oxidize CuI in the presence of UV light. The photo-degradation mechanism of the cells is thus discussed on the basis of the photo-oxidative function of TiO₂. The long-term stability of the solid-state dye-sensitized solar cell (DSSC) was found to be improved under simulated sunlight by coating the TiO₂ porous electrode with an ultra-thin MgO layer, which was able to block the photo-oxidative activity of the TiO₂.     

Improving the performance of solid-state dye-sensitized solar cell using MgO-coated TiO2 nanoporous film

An ultrathin overlayer of MgO on TiO2 is shown to drastically improve the stability of solid-state dye-sensitized solar cell using CuI as a hole conductor in addition to solar energy conversion efficiency.     

Recent research progress on quasi-solid-state electrolytes for dye-sensitized solar cells

Dye-sensitized solar cells(DSSCs) are the most promising, low cost and most extensively investigated solar cells. They are famous for their clean and efficient solar energy conversion. Nevertheless this, long-time stability is still to be acquired. In recent years research on solid and quasi-solid state electrolytes is extensively increased. Various quasi-solid electrolytes, including composites polymer electrolytes, ionic liquid electrolytes,thermoplastic polymer electrolytes and thermosetting polymer electrolytes have been used. Performance and stability of a quasi-solid state electrolyte are between liquid and solid electrolytes. High photovoltaic performances of QS-DSSCs along better long-term stability can be obtained by designing and optimizing quasi-solid electrolytes. It is a prospective candidate for highly efficient and stable DSSCs.     

Quasi solid-state electrolytes based on ionic liquid (IL) and ordered mesoporous matrix MCM-41 for supercapacitor application

Journal of Solid State Electrochemistry - Quasi solid-state electrolytes (QS-SEs) based on an ionic liquid ([EMIM][FSI]) immobilized in ordered mesoporous silica MCM-41 using physical imbibition...     

Composite electrolytes based on poly(ethylene oxide) and binary ionic liquids for dye-sensitized solar cells

The sunlight is the largest single available source of clean and renewable energy to ensure human society’s sustainable development. Owing to their low production cost and high energy conversion efficiency, dye-sensitized solar cells (DSSCs) have been regarded as good alternatives to conventional photovoltaic devices. Herein, a series of composite electrolytes based on poly(ethylene oxide) (PEO) and the binary ionic liquids 1-propyl-3-methy-imidazolium iodide ([PMIm]I) and 1-ethyl-3-methylimidazolium thiocyanate ([EMIm][SCN]) were prepared and then applied to fabricate six DSSCs. The composite electrolytes were characterized by fourier transform infrared spectroscopy (FTIS), X-ray diffraction (XRD), and electrochemical impedance spectra (EIS). It was shown that the addition of binary ionic liquids would reduce the degree of crystallinity of PEO, thus improving the ionic conductivities of the electrolytes by about 2 orders of magnitude. Investigation on the photovoltaic performances of these DSSCs showed that the fill factor (FF) could reach up to 0.67 and energy conversion efficiency (η) could reach up to 4.04% under AM 1.5 full sunlight (100 mW/cm2).     

Energy-storable dye-sensitized solar cell with a polypyrrole electrode

A three-electrode-type solar-rechargeable battery, energy-storable dye-sensitized solar cell (ES-DSSC), has been constructed by the hybridization of a typical Gratzel cell and a conducting polymer charge-storage electrode; efficient photo-charging can be accomplished by visible-light irradiation.     

Gelation of ionic liquid-based electrolytes with silica nanoparticles for quasi-solid-state dye-sensitized solar cells

For the first time silica nanoparticles were used to solidify ionic liquids. These ionic liquid-based quasi-solid-state electrolytes were successfully employed for regenerative photoelectrochemical cells that yielded 7% efficiency at AM 1.5 sunlight in combination with an amphiphilic ruthenium polypyridyl photosensitizer.