Triiodide Diffusion Coefficient Research Articles

Sonochemically tailored Copper Oxide as nanofiller in terpolymer composite gel electrolytes for dye-sensitized solar cells

This article describes the impact of several weight percentages of copper oxide (CuO) as a nanofiller on the structure, morphology, and electrochemical performance of dye-sensitized solar cells (DSSC). CuO-350 was synthesized using a sonochemical method following by calcination at 350 ℃ and was incorporated into the polymer-salt system to develop a polymer composite gel electrolyte (PCGE). The improvement in the amorphous phase and complexation between the constituents were proven via X-ray diffraction, and Fourier transform infrared. However, the thermal stability declines with the addition of CuO-350 nanofillers. It was found that TCuO350–5 exhibited the highest ionic conductivity and apparent diffusion coefficient of triiodide of (3.49±0.01)×10−3 S cm−1 and 1.48 × 10−5 cm2 s−1, respectively. The best-performing sample among PCGE is found to be TCuO350–5, containing 5 wt% of CuO-350 with an efficiency of 7.69% with JSC of 23.47 mA cm−2, VOC of 0.62 V, and fill factor of 52.9%. In addition, it also has the highest charge collection efficiency (87.31%) and longest electron lifetime (1.446 s). TCuO350–5 has achieved the stability of the device with efficiency retained 92% at room temperature and retains 80% efficiency even at 80 ℃.

Synthesis of Crosslinked Hydroxypropyl Methylcellulose with Methyl Gallate‐Poly(Ethylene Glycol) as a Gel Electrolyte for Dye‐Sensitized Solar Cells

Hydroxypropyl methylcellulose (HPMC) is blended with methyl gallate (MG) encapsulated with poly(ethylene glycol) (PEG) and then mixed with a liquid electrolyte to prepare a polymer gel electrolyte. The structural and physical properties of prepared polymer gels are analyzed by various analytical instruments. The MG‐PEG‐HPMC hybrid is found to be able for entrapping a large amount of liquid electrolyte and is used to fabricate dye‐sensitized solar cells (DSSCs). This polymer gel electrolyte shows high ionic conductivity (5.43 × 10−4 S cm−1) and good triiodide diffusion coefficient (2.25 × 10−6 cm2 s−1). The resulting DSSCs show an efficiency of 6.96% at a light intensity of 85 mW cm−2. The long‐term stability test reveals that the fabricated DSSCs will be stable even after 500 h. The benefits of incorporating a gel electrolyte into DSSCs are highlighted along with factors affecting the stability of these devices. The use of these bio‐based materials has the potential to make a significant contribution to the widespread exploitation of stable, efficient, and low‐cost dye‐sensitive solar cells.

Modification of DSSC Based on Polymer Composite Gel Electrolyte with Copper Oxide Nanochain by Shape Effect.

Solvent evaporation and leakage of liquid electrolytes that restrict the practicality of dye-sensitized solar cells (DSSCs) motivate the quest for the development of stable and ionic conductive electrolyte. Gel polymer electrolyte (GPE) fits the criteria, but it still suffers from low efficiency due to insufficient segmental motion within the electrolytes. Therefore, incorporating metal oxide nanofiller is one of the approaches to enhance the performance of electrolytes due to the presence of cross-linking centers that can be coordinated with the polymer segments. In this research, polymer composite gel electrolytes (PCGEs) employing poly (vinyl butyral-co-vinyl alcohol-co-vinyl acetate) (P(VB-co-VA-co-VAc)) terpolymer as host polymer, tetrapropylammonium iodide (TPAI) as dopant salt, and copper oxide (CuO) nanoparticles as the nanofillers were produced. The CuO nanofillers were synthesized by sonochemical method and subsequently calcined at different temperatures (i.e., 200, 350, and 500 °C), denoted as CuO-200, CuO-350, and CuO-500, respectively. All CuO nanoparticles have different shapes and sizes that are connected in a chain which impact the amorphous phase and the roughness of the surface, proven by the structural and the morphological analyses. It was found that the PCGE consisting of CuO-350 exhibited the highest ionic conductivity of 2.54 mS cm−1 and apparent diffusion coefficient of triiodide of 1.537 10−4 cm2 s−1. The enhancement in the electrochemical performance of the PCGEs is correlated with the change in shape (rod to sphere) and size of CuO particles which disrupted the structural order of the polymer chain, facilitating the redox couple transportation. Additionally, a DSSC was fabricated and achieved the highest power conversion efficiency of 7.05% with JSC of 22.1 mA cm−2, VOC of 0.61 V, and FF of 52.4%.

Seawater-based electrolytes facilitate charge transfer mechanisms improving the efficiency of dye-sensitized solar cells

In this work, dye-sensitized solar cells containing seawater-based electrolytes were realized and investigated. The influence of the seawater composition on the electrochemical properties of the iodide/triiodide redox mediator was determined. High triiodide diffusion coefficient and ionic conductivity were assessed for seawater electrolytes through cyclic and linear voltammetry and impedance spectroscopy. Moreover, a notable influence of the seawater electrolyte on the charge transfer mechanism at the photoanode/dye/electrolyte interfaces was observed and deeply discussed. The ions, naturally present into seawater, reduce the charge recombination mechanism at the photoanode/electrolyte interface and promote a downward shift of the TiO2 conduction band, thus increasing the final DSSC efficiencies of 23% if compared with traditional devices containing water. The best seawater-based solar cell provides a photo-electrical conversion efficiency equal to 0.37% with 1.09 mA cm−2 as short circuit current density. To the best of our knowledge, this is the first time that seawater is used as a key component for an energy production technology and the obtained results show the great potentiality of this green and recyclable element.

Evaluation of canonical choline chloride based deep eutectic solvents as dye-sensitized solar cell electrolytes.

Deep eutectic solvents (DESs) are beginning to attract interest as electrolyte alternatives to conventional organic solvents and ionic liquids within dye-sensitized solar cells (DSSCs). The precise roles played by DES components and whether they simply represent a benign medium for mobilizing charge carriers or present beneficial functionality that impacts device performance remain unclear. To begin to address this deficiency in understanding, we performed a comprehensive characterization of the three "canonical" choline chloride-based DESs (i.e., reline, ethaline, and glyceline) as DSSC electrolytes hosting the iodide-triiodide (I-/I3 -) redox couple. The measurement of electrolyte viscosities, determination of triiodide diffusion coefficients, and photovoltaic performances assessed for water contents up to 40 wt. % allow the emergence of several important insights. A comparison to the observed photovoltaic performance arising from the individual components aids in further clarifying the impact of DES chemistry and solution viscosity on photovoltaic and charge carrier diffusion characteristics. Finally, we introduce the DES guaniline-consisting of a 1:1 molar ratio mixture of choline chloride with guanidinium thiocyanate-demonstrating it to be a superior DSSC electrolyte over those formulated from the three most widely studied canonical DESs at all water contents investigated.

Enhancing the Efficiency of a Dye-Sensitized Solar Cell Based on a Metal Oxide Nanocomposite Gel Polymer Electrolyte.

To overcome the critical limitations of liquid-electrolyte-based dye-sensitized solar cells, quasi-solid-state electrolytes have been explored as a means of addressing long-term device stability, albeit with comparatively low ionic conductivities and device performances. Although metal oxide additives have been shown to augment ionic conductivity, their propensity to aggregate into large crystalline particles upon high-heat annealing hinders their full potential in quasi-solid-state electrolytes. In this work, sonochemical processing has been successfully applied to generate fine Co3O4 nanoparticles that are highly dispersible in a PAN:P(VP-co-VAc) polymer-blended gel electrolyte, even after calcination. An optimized nanocomposite gel polymer electrolyte containing 3 wt % sonicated Co3O4 nanoparticles (PVVA-3) delivers the highest ionic conductivity (4.62 × 10-3 S cm-1) of the series. This property is accompanied by a 51% enhancement in the apparent diffusion coefficient of triiodide versus both unmodified and unsonicated electrolyte samples. The dye-sensitized solar cell based on PVVA-3 displays a power conversion efficiency of 6.46% under AM1.5 G, 100 mW cm-2. By identifying the optimal loading of sonochemically processed nanoparticles, we are able to generate a homogenous extended particle network that effectively mobilizes redox-active species through a highly amorphous host matrix. This effect is manifested in a selective 51% enhancement in photocurrent density (JSC = 16.2 mA cm-2) and a lowered barrier to N719 dye regeneration (RCT = 193 Ω) versus an unmodified solar cell. To the best of our knowledge, this work represents the highest known efficiency to date for dye-sensitized solar cells based on a sonicated Co3O4-modified gel polymer electrolyte. Sonochemical processing, when applied in this manner, has the potential to make meaningful contributions toward the ongoing mission to achieve the widespread exploitation of stable and low-cost dye-sensitized solar cells.

Quasi solid-state dye-sensitized solar cell with P(MMA-co-MAA)-based polymer electrolytes

A series of poly (methylacrylate-co-methylacrylic acid) (P(MMA-co-MAA)) gel polymer electrolytes containing iodide/triiodide (I−/I3−) redox mediator from sodium iodide (NaI) dopant salt was synthesized and studied on their conductivity and power conversion efficiency as applied in dye-sensitized solar cells (DSSC). A relationship of complex permittivity with increasing frequency was established as well as dispersion relation with modulus studies. Temperature dependence study forms an Arrhenius plot and the highest ionic conductivity achieved was 1.07 mS cm−1 at room temperature with activation energy of 0.224 eV for the gel polymer electrolytes (GPE) with 40 wt% NaI. Fourier transform infrared (FTIR) and X-ray diffraction (XRD) spectroscopy was utilized to evaluate the formation of complexes between the copolymer and salt. Again at 40 wt% NaI, the best performance was observed under photovoltaic investigation using DSSC with energy conversion efficiency of 2.34%. To further understand the electrochemical properties of the GPE, steady-state measurement of triiodide diffusion coefficient was done.

Thiourea incorporated poly(ethylene oxide) as transparent gel polymer electrolyte for dye sensitized solar cell applications

Abstract A new series of transparent gel polymer electrolytes are prepared by adding various weight percent of thiourea coupled with poly(ethylene oxide) for the application of dye-sensitized solar cells. Coupling of thiourea in the presence of iodine undergoes dimerization reaction to produce formamidine disulfide. Fourier Transform Infrared spectroscopy shows that the interactions of thiourea and formamidine disulfide with electronegative ether linkage of poly(ethylene oxide) results in conformational changes of gel polymer electrolytes. Electrochemical impedance spectroscopy and linear sweep voltammetry experiments reveal an increment in ionic conductivity and tri-iodide diffusion coefficient, for thiourea modified gel polymer electrolytes. Finally, the prepared electrolytes are used as a redox mediator in dye-sensitized solar cells and the photovoltaic properties were studied. Apart from transparency, the gel polymer electrolytes with thiorurea show higher photovoltaic properties compared to bare gel polymer electrolyte and a maximum photocurrent efficiency of 7.17% is achieved for gel polymer electrolyte containing 1 wt% of thiourea with a short circuit current of 11.79 mA cm −2 and open circuit voltage of 834 mV. Finally, under rear illumination, almost 90% efficiency is retained upon compared to front illumination.

Poly(ethylene oxide) polymer matrix coupled with urea as gel electrolyte for dye sensitized solar cell applications

In this paper, a new series of gel polymer electrolytes modified with various weight percent of urea in Poly(ethylene oxide) polymer matrix and iodine-iodide based redox couple were reported for the application of dye-sensitized solar cell. The effect of urea on both molecular mobility and final morphology of GPE are characterized by Fourier Transform Infrared spectroscopy and Scanning Electron Microscopy. Electrochemical Impedance Spectroscopy and Linear Sweep Voltammetry show that the addition of urea gives a general increment in both ionic conductivity (σ) and tri-iodide diffusion coefficient. In particular, GPE containing 4wt% of urea has an ionic conductivity, σ=4.28×10−4Scm−1 and tri-iodide diffusion coefficient, DI3−=2.06×10−6cm2s−1. A maximum power conversion efficiency of 6.82% in the photovoltaic performance is achieved. Further, a variation of charge transfer resistance and chemical capacitance at the TiO2/dye/interfaces as a function of bias voltage is observed. It suggests an upward shift in the conduction band of TiO2 in the case of gel electrolytes.

Binary Ionic Liquid Electrolyte for Dye-Sensitized Solar Cells

Binary ionic liquid composed of 1-propyl-3-methylimidazolium iodide (PMII) and 1-butyl-3-methylimidazolium thiocyanate (BMISCN) were mixed at four different ratios to study its effect on the dye-sensitized solar cells’ (DSSCs) efficiency. The addition of low viscosity ionic liquid which is BMISCN is to overcome the low mass transportation of iodide/triiodide faced by pure PMII. Therefore, the effect of mixing different ratios of these ionic liquids on the viscosity and triiodide diffusion coefficient were studied and the best ratio was identified. Based on the experimental work, the mixture of BMISCN with PMII of higher viscosity has allowed reducing the mass transport limitation of tri-iodide in the electrolyte as the effect of lowering the overall ionic liquid's viscosity. The binary electrolyte PMII: BMISCN (1:0.75) give the highest power conversion efficiency of 1.89%, with a fill factor of 0.47, open circuit voltage of 0.62, and short circuit current density of 6.52mA/cm2 and triiodide diffusion coefficient of 8.47 x 10−7 cm2 s-1. This work has provided valuable insight for further development of binary ionic liquid electrolyte for DSSCs.

Fabrication of Stable Dye Sensitized Solar Cell with Gel electrolytes Using Poly(ethylene oxide)-Poly(ethylene glycol)

Fabrication of quasi solid state dye sensitized solar cell with a stable gel electrolyte employing poly(ethylene oxide) (PEO)-poly(ethylene glycol) (PEG) is reported in this paper. PEO-PEG with either one of alkali iodides (LiI or NaI or KI), 1,2-dimethyl-3-propyl imidazolium iodide (DMPI), 4-tertbutylpyridine (TBP) and iodine in acetonitrile were used for the gel electrolyte preparation. The ionic conductivity and the triiodide diffusion coefficient of the gel electrolytes were measured by Electrochemical Impedance Spectroscopy. The photoconversion efficiency of gel state DSSC with NaI was found to be 5.4% at 100mW/cm2 with AM 1.5 Gfilter. When nanocrystalline TiO2 was used as the filler in the gel electrolyte, the photoconversion efficiency was found to be increased up to 6.3%. The quasi solid state DSSC retained its initial value for 600hours aging under ambient conditions.

Fabrication of dye sensitized solar cell using gel polymer electrolytes consisting poly(ethylene oxide)-acetamide composite

Gel polymer electrolytes (GPEs) are synthesized by incorporating different wt% (0%, 2%, 4%, 5%, 6% and 8%) of acetamide in poly (ethylene oxide) (PEO) with LiI/I2. The conformational, electrochemical, photoelectrochemical characteristics of the prepared GPEs are studied. Among the electrolytes, PEO with 5 wt% acetamide shows the highest efficiency (η = 9.01%) compared to original GPE without acetamide (5.7%) under 85 mW cm−2 illumination. The increase in open circuit voltage (Voc) is noticed for gel polymer electrolytes may be due to the reduction in the recombination reaction and increase in the electron life time upon incorporation of acetamide on the PEO. The observed increment in short circuit current density (Jsc) is attributed to the increase in the ionic conductivity and tri-iodide diffusion co-efficient, since incorporation of acetamide on the PEO increases the amorphous nature of the electrolyte.

A one-pot route to prepare class II hybrid ionogel electrolytes

A new system based on class II hybrid ionogels (Si-IL gels) has been developed for overcoming leaking problems associated with liquid electrolytes in dye-sensitized solar cells (DSSCs). We co-condensed a silica precursor with an alkoxysilane functionalized ionic liquid precursor, under acidic conditions, to obtain a hybrid ionogel where ionic liquid is covalently linked to silica domains. The morphology and the microstructure of the Si-IL xerogels were explored using NMR, SAXS and field emission scanning electron microscopy (FE-SEM). Cyclic voltammetry experiments were carried out to measure the apparent diffusion coefficient of the redox couple I−/I3− into these Si-IL gels. The diffusion coefficient of triiodide in the gel is comparable to the one observed in a solvent-free based ionic liquid electrolyte. These Si-IL gels were evaluated as electrolytes in quasi-solid-state DSSCs. For this purpose, various DSSCs have been fabricated. The cells containing Si-IL ionogels with 50 wt% of a silica modified liquid ionic precursor exhibit a short-circuit photocurrent of 2.8 mA cm−2, an open circuit voltage of 680 mV, a fill factor of 0.65, and an overall efficiency of 1.25%. Accordingly, this work constitutes a proof of concept.

Enhanced photovoltaic performance of quasi-solid-state dye-sensitized solar cells by incorporating a quaternized ammonium salt into poly(ethylene oxide)/poly(vinylidene fluoride-hexafluoropropylene) composite polymer electrolyte

Quasi-solid-state dye-sensitized solar cells (DSSCs) are fabricated using tetraethylammonium tetrafluoroborate (Et4NBF4)-modified poly(ethylene oxide)/poly(vinylidene fluoride-hexafluoropropylene) (PEO/P(VDF-HFP)) composite polymer electrolytes (CPEs) along with KI and I2. Compared to the original CPE, the addition of Et4NBF4 mainly changes the conformation of the polymer structure, reduces the crystallinity of the polymer electrolyte specifically, and hence, increases the triiodide diffusion coefficient and the ionic conductivity, leading to the notable improved photovoltaic performance of DSSC. The DSSC based on the Et4NBF4 (0.15g)-modified CPE exhibits the best performance, with a short current density of 14.70mAcm−2 and a photoenergy conversion efficiency of 6.243% under an irradiance of 96.17mWcm−2.

Ionic liquid redox electrolytes based on binary mixtures of 1-alkyl-methylimidazolium tricyanomethanide with 1-methyl-3-propylimidazolium iodide and implication in dye-sensitized solar cells

Innovative redox electrolytes for dye-sensitized solar cells (DSCs) were prepared using binary mixtures of 1-methyl-3-propylimidazolium iodide (MPII) with 1-alkyl-methylimidazolium tricyanomethanide, CνmimTCM (ν = 2, 4, 6, 8) ionic liquids (ILs) to lower the high viscosity of MPII. The investigation of the physicochemical properties of the IL blends as a function of temperature has shown that both density and viscosity strongly depend on the kind of the Cνmim cation in the mixture. The corresponding Raman spectra were dominated by the vibrational modes of the IL components in an additive way and confirmed the absence of any specific interaction, independent of the Cν alkyl chain length. The electrochemical properties (triiodide diffusion coefficients, specific conductivity), determined in symmetrical thin layer cells using polarization and electrochemical impedance spectroscopy (EIS) measurements, have shown that both diffusion and conductivity decreased with increasing viscosity, and further confirmed the electrolytes' compatibility with the cathode. Incorporation of the novel electrolytes in DSC devices revealed a systematic dependence of the cell photovoltaic performance on the alkyl chain length of CνmimTCM; the maximum power conversion efficiency exceeded 5 and 6.5% under 1 and 0.1 sun AM 1.5 G illumination, respectively, for the ionic liquid with the shortest alkyl chain. The solar cells were further characterized by EIS (IMPS) spectroscopy, exploring charge recombination dynamics and identifying conduction band edge shifts. Solidification of the electrolytes with silica nanoparticles, demonstrated that the ionic liquid electrolytes with long chain length (ν > 4) not only retain their efficiencies, but also exhibit a 22% efficiency enhancement, which is most pronounced for the electrolytes employing ionic liquids with the longest (hexyl- and octyl-) alkyl chains.

Investigation of the role of anions in hydrotalcite for quasi-solid state dye-sensitized solar cells application

In recent research in clean energy applications, clay has gained significant interest, especially as a gelator in dye-sensitized solar cells (DSSCs), for its capability to resolve the leakage issue of liquid electrolyte. In this paper, anionic hydrotalcite is utilized as a gelator to assist the formation of gel electrolyte in DSSCs. Three types of hydrotalcite with exchangeable anions, viz. NO3− (CL-N), CO32− (CL-C) and SO42− (CL-S), were synthesized with similar morphologies via the co-precipitation method. It is observed that the gel formation of hydrotalcite strongly depends on the exchangeable anions present in the hydrotalcite. The objective of this work is to understand the effect of hydrotalcite anions on the photovoltage and the photocurrent in the gel electrolyte through electrochemical analysis. With increasing ion affinity, the Voc increases. This is attributed to Li+ intercalation with hydrotalcite compound resulting in the elevation of the conduction band of TiO2. With increasing ion affinity, the Jsc decreases. This is attributed to the decreasing diffusion coefficient of triiodide and the increasing difficulty in the injection process. For anions with low ion affinity in hydrotalcite, the diffusion of the redox couple is not significantly affected by the high viscosity of the gel. Furthermore, the study indicates that proper selection of hydrotalcite compounds not only produces a quasi-solid gel electrolyte, but also increases the efficiency of the solar cells: the device performance was improved from 7.8% (liquid electrolyte) to 8.4% (hydrotalcite gel electrolyte).

Preparation of Jeffamine based quaternary ammonium iodide melt for dye sensitized solar cells

A novel Jeffamine based Quaternary Ammonium Iodide (JQAI) melt which contains ether group in backbone were designed and synthesized as non-volatile iodide resource for fabrication of dye sensitized solar cells. 1H NMR spectroscopy and electrospray mass spectrometry techniques were used to confirm the formation of novel ionic liquid. The apparent diffusion coefficient (Dapp) of triiodide and iodide in novel ionic liquid demonstrated by steady state voltammogram shows linear increase on increasing the concentration of iodine from 0.1 to 0.5M. With 0.5M I2, the value of Dapp for triiodide and iodide was found to be 7.502×10−8cm2s−1 and 15.04×10−8cm2s−1 respectively. JQAI was successfully used as an iodide resource for dye sensitized nanocrystalline solar cells. Using this ionic liquid a maximum of 2.34% efficiency was obtained with the observed photo-voltage of 0.536V and photocurrent of 4.65mA using the electrolyte composition 0.5M I2 in JQAI for fabricated dye sensitized solar cell. Addition of small concentration of LiI (0.1M) to the electrolyte containing 0.5M I2 leads to further increase in the photo‐voltage from 0.536 to 0.686V which results in higher energy conversion efficiency (3.03%). Such substantial increase in efficiency was ascribed to the attraction of Li cation towards the large electronegative oxygen atom reside in the quaternary ammonium ionic liquid.

Influence of cations of the electrolyte on the performance and stability of dye sensitized solar cells

The electrolyte is one of the key components for DSC and its properties have great influence on the photo-conversion efficiency and stability of the devices. Five new low volatile electrolytes containing 3-methoxypropionitrile (MPN) as solvent were prepared with different cationic structures of the iodide source to evaluate their photovoltaic performance in dye-sensitized solar cells. We are interested in studying the role of cations in the device performance and selected the cations of iodide salts such as 1,3-dimethylimidazolium, 1,2-dimethyl-3-propylimidazolium, 1-ethyl-1-methylpyrrolidinium, tetrabutylammonium and 1-propylpyridinium for comparison. These electrolytes are characterized by measuring the triiodide diffusion coefficients using both electrochemical impedance spectroscopy (EIS) and cyclic voltammetry. In combination with the Ruthenium C106 dye these newly developed electrolytes show an initial power conversion efficiency between 8 and 9% under full sunlight at AM1.5G conditions. The DSC devices prepared with these electrolytes subjected to prolonged aging under full sunlight at 60 °C showed excellent stability. EIS has been employed to characterize the photovoltaic parameter variations observed during the durability tests.

Effects of environmentally benign solvents in the agarose gel electrolytes on dye-sensitized solar cells

The ionic agarose gel electrolytes are prepared by using environmental benign solvents and co-solvents to improve the agarose solubility and capacities of the additives for dye-sensitized solar cells. The effects of single solvents (dimethyl sulfoxide (DMSO), propylene carbonate (PC), propylene glycol, triethylene glycol, and tetraethylene glycol) and DMSO-based co-solvents are examined on the conductivities, diffusion coefficients of triiodide, and energy conversion efficiencies. The highest conductivity, 14.2 mS cm −1, and the highest diffusion coefficient of triiodide, 2.7 × 10 −6 cm 2 s −1, are achieved for the electrolyte containing the co-solvent of 80 vol.% PC and 20 vol.% DMSO. The environmental benign co-solvent such as DMSO/PC can significantly increase the conversion efficiency to 3.4% with agarose compared to pure MPII with agarose (1.4%), while retaining ∼80% of the energy conversion efficiencies of the reference cell without agarose under the illumination at AM 1.5, 100 mW cm −2.

Evidence for enhancing charge collection efficiency with an alternative cost-effective binary ionic liquids electrolyte based dye-sensitized solar cells

To mitigate the mass transfer limitations of a highly viscous room temperature ionic liquid (RTIL) electrolyte, systematic characterizations of viscosity, ionic conductivity, apparent triiodide diffusion coefficient and photovoltaic response of an alternative cost-effective and highly conductive binary RTIL mixture of 1-ethyl-3-methylimidazolium trifluoroacetate (EMIATF) and 1-methyl-3-propylimidazolium iodide (PMII) were investigated. An emphasis was placed on the dynamics of electron transport and charge recombination processes; specifically, a focus was placed on the effective electron diffusion length and charge collection efficiency in the devices. Notably, the introduction of perfluorinated anions, with a strong delocalization of the negative charge over the anion backbone, was able to weaken the hydrogen bonding with the imidazolium cations and, thus, decrease the viscosity and increase the ionic conductivity of the electrolyte. A sealed device that employed the binary RTIL achieved an overall conversion efficiency of 5.22% under irradiation of 100 mW cm −2, which increased the value by 30% compared to a device with a blank PMII-based RTIL electrolyte. Electrochemical impedance spectroscopy and intensity-modulated photovoltage/photocurrent spectroscopy analysis revealed that employment of this alternative binary RTIL electrolyte system was able to significantly decrease the diffusion resistance of triiodide species in the electrolyte and retard the charge recombination between the injected electrons with triiodide anions in the electrolyte, thus improving the effective electron diffusion length and charge collection efficiency in the device. The charge collection efficiency was certified to be the dominant parameter governing the short-circuit photocurrent density and the overall conversion efficiency of devices with RTIL electrolyte.