Application In Dye-sensitized Solar Cells Research Articles

Asymmetric phthalocyanine compounds in the structure D-π-A containing cyano groups: Design, synthesis and dye-sensitized solar cell applications

In this study, asymmetric zinc phthalocyanine compounds with Donor-π-Anchor (D-π-A) property that enable the movement of electrons in molecular structure in one direction were synthesized. Phthalocyanines were designed to ensure electron mobility within the molecule and to facilitate the transfer of electrons to the TiO2 layer. The synthesized asymmetric zinc phthalocyanines (ZnPc-1 and ZnPc-2) are molecules with three donor biphenyls and one anchor aldehyde group and three acceptor/anchor cyano and one anchor aldehyde group, respectively. The effect of biphenyl and cyano groups on cell efficiency with aldehyde anchor group was investigated. The structure of the synthesized phthalocyanines was characterized by Fourier Transform Infrared Spectrometry (FTIR), Mass Spectrometry (MS), UV-vis, Fluorescence spectroscopy. The experimentally calculated optical band gap values were supported by the values found by Density Functional Theory (DFT) calculations. dye sensitive solar cells were measured and the efficiencies were evaluated with reference to the N719 standard dye. In the solar cell measurements of the designed phthalocyanines, the structure containing the cyano group has been given a higher photovoltaic cell thanks to the higher short circuit photo-current (Jsc). In this way, the highest power conversion efficiency value was achieved among the cyano group molecules.

Ragi (finger millet) starch-based gel electrolytes for dye-sensitized solar cell application

Ragi (finger millet) starch-based gel electrolytes for dye-sensitized solar cell application

A computational approach on engineering short spacer for carbazole-based dyes for dye-sensitized solar cells

Donor-π-linker-acceptor (D-π-A) push–pull dye molecules are most common in dye-sensitized solar cells (DSSCs) applications. Selection of dye molecules for DSSCs is based on their ability to absorb light in the visible spectrum. This can be done more efficiently by positioning the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) with respect to the conduction band of the semiconductor and the redox potential of the electrolyte, respectively. The photocurrent is manipulated by the extent of light absorption, planarity of the π-linker for efficient intramolecular charge transfer (ICT), oxidized dye reorganization energy (Λ) and dye regeneration driving force (ΔGreg). In a quest of achieving panchromatic absorption up to near-IR region, mostly electron-rich chromophores and their oligo form were used in the π-segment, but this approach led to poor ICT. In this computational analysis, we have explored the effect of electron-withdrawing (cyano (–CN)) and donating groups (methoxy (-OMe)) in three different π-segment length to understand the carbazole dyes’ suitability for DSSCs using onset wavelength (λonset), Λ, ICT and ΔGreg as the figure-of-merits.

Facile synthesis of SnS nanostructures with different morphologies for supercapacitor and dye-sensitized solar cell applications

In this paper, tin Sulfide (SnS) nanoparticles are synthesized with three different solvents through hydrothermal method and characterized by using X-ray diffraction, scanning electron microscopy, UV-DRS spectroscopy, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectrum, supercapacitor, and photovoltaic performance. XRD patterns indicate that the prepared SnS nanoparticles exist in the orthorhombic phase. The SEM analysis clearly picturizes the morphological changes in the SnS nanoparticles synthesized through different solvents. The UV-DRS spectrum gives direct energy band gap which lies between 1.0 and 2.0 eV. The FT-IR spectrum explains various functional groups present in the SnS nanoparticles. The prepared SnS counter electrodes (CEs) showed good electrocatalytic activity in the redox reaction of the I−/I3−. The efficiency of tin sulfide prepared in ethanol (SnS-e), tin sulfide prepared in acetone (SnS-a), and tin sulfide prepared in methanol (SnS-m) counter electrodes (CEs) are 9.99%, 9.90%, and 9.86% in Dye-sensitized solar cells (DSSC) than that of platinum counter electrode which is 9.80%. The specific capacitance of 284 F/g is obtained for SnS-e electrode at a current density of 5 A/g and an energy density of 216 Wh/kg corresponding to power density value of 1.6 KWh/kg which proves SnS-e electrode possesses better capacitive performance than SnS-a and SnS-m electrodes, respectively.

Electronic, Structural, and Optical Properties of Mono-Doped and Co-Doped (210) TiO2 Brookite Surfaces for Application in Dye-Sensitized Solar Cells-A First Principles Study.

Titanium dioxide (TiO2) polymorphs have recently gained a lot of attention in dye-sensitized solar cells (DSSCs). The brookite polymorph, among other TiO2 polymorphs, is now becoming the focus of research in DSSC applications, despite the difficulties in obtaining it as a pure phase experimentally. The current theoretical study used different nonmetals (C, S and N) and (C-S, C-N and S-N) as dopants and co-dopants, respectively, to investigate the effects of mono-doping and co-doping on the electronic, structural, and optical structure properties of (210) TiO2 brookite surfaces, which is the most exposed surface of brookite. The results show that due to the narrowing of the band gap and the presence of impurity levels in the band gap, all mono-doped and co-doped TiO2 brookite (210) surfaces exhibit some redshift. In particular, the C-doped, and C-N co-doped TiO2 brookite (210) surfaces exhibit better absorption in the visible region of the electromagnetic spectrum in comparison to the pure, S-doped, N-doped, C-S co-doped and N-S co-doped TiO2 brookite (210) surfaces.

Effect of concentration of MoS2 on the TCO-Pt free polyaniline nano-rod based counter electrode for dye sensitised solar cell application

ABSTRACT The concentration effect of molybdenum disulphide (MoS2) on the catalytic activity of polyaniline (PANi)-based counter electrode (CE) was investigated for cost-effective replacement of both transparent conducting oxide (TCO) and platinum (Pt) for dye-sensitised solar cell application (DSSC). Simple chemical mixing is employed to introduce 0.5 wt%, 2 wt%, 5 wt%, 7 wt% and 9 wt% MoS2 nanoparticles in the optimised thickness of PANi matrix. The drop-casting method is used to achieve a uniform layer on a normal glass substrate. Morphology and structural composition were studied using scanning electron microscopy and X-ray diffraction. Fourier transform infrared was used to identify redox-active functionalities. Electrochemical impedance spectroscopy and cyclic voltammetry were employed to study electron transfer and catalytic activity. Finally, I–V testing was carried out using asun simulator. Aremarkable 9.02% efficiency has been exhibited by PANi-7 wt% MoS2 nanocomposite CE-based DSSC which is 9.73% higher compared to TCO-Pt CE-based DSSC.

Dye-Sensitized Solar Cell for Building-Integrated Photovoltaic (BIPV) Applications

One of the important research directions in the field of photovoltaics is integration with construction. The integration of solar cell systems with a building can reduce installation costs and help optimize the used space. Among the few literature reports on photovoltaic roof tiles, solutions with silicon and thin film solar cells dominate. An interesting solution may be the application of dye-sensitized solar cells. In addition to their interesting properties, they also have aesthetic value. In the classic arrangement, they are constructed using glass with a transparent conductive layer (TCL). This article describes replacing a classic glass counter electrode with an electrode based on a ceramic tile and nickel foil. First, a continuous and homogeneous fluorine-doped tin oxide (FTO) thin film was developed so that the above-mentioned substrate could be applied. The atomization method was used for this purpose. Then, nanocolloidal platinum paste was deposited as a catalytic material using the screen printing method. The electrical parameters of the manufactured DSSCs with and without a counter electrode tile were characterized by measuring their current–voltage characteristics under standard AM 1.5 radiation. A dye-sensitized solar cell integrated with ceramic tiles and nickel foil was produced and displayed an efficiency of over 4%. This solution makes it possible to expand their construction applications. The advantage of this solution is full integration with construction, while simultaneously generating electricity. A dye-sensitized solar cell was built layer-by-layer on a ceramic tile and nickel foil.

Quantum chemical designing of 2-(3,4-dihydroxyphenyl)-3,5,7- trihydroxychromenium as a efficient sensitizer for dye sensitized solar cell

In this study we have designed six metal free D–π–A system and evaluated their optimum properties for Dye sensitized solar cell (DSSC). The ground state geometries, electronic properties, light harvesting efficiency, and electronic absorption spectra of these dyes were studied using Density functional theory and Time dependant density functional theory. All these calculations were performed in the gas phase and Dimethylformamide, Dichloromethane as solvent. Our theoretical calculation reveals that the designed metal free organic dyes are good candidate for DSSC applications.

Correction to: Structural and optical analysis of Ag nanoparticle-assisted and vertically aligned TiO2 nanowires for potential DSSCs application

In this work, vertically aligned TiO2 nanowires (TiO2-NWs) and Ag nanoparticle (Ag-NP)-assisted and vertically aligned TiO2 nanowires (TAT-NWs) were deposited on glass and flexible polyethylene terephthalate (PET) substrates using the glancing angle deposition (GLAD) technique. The morphology and structural analysis of the samples manifest successful deposition of vertically aligned TiO2-NWs and TAT-NWs. The high-resolution transmission electron microscopy (HR-TEM) image of TiO2-NWs shows the polycrystalline nature. Further, the X-ray diffraction (XRD) result confirms the polycrystalline nature of both the TiO2-NW and TAT-NW samples. Besides, HR-TEM image confirms the presence of small crystal grains of Ag-NPs at the mid of the annealed TAT-NWs. It is evident from the selected area electron diffraction (SAED) analysis of TiO2-NWs and annealed TAT-NWs that the crystallinity of TiO2 present in the annealed TAT-NWs improves after annealing. The absorption spectrum analysis of TAT-NWs deposited on glass substrate shows enhances absorption peak in the visible region with a maximum peak at ~ 450 nm wavelength compared to the TiO2-NWs, which may be attributed to the surface plasmon resonance (SPR) effect of Ag-NPs. Further, it is interesting to observe that the TAT-NWs deposited on PET substrate show further absorption enhancement in the UV and visible regions. In addition, the photoluminescence (PL) analysis reveals that the band gap of TiO2-NWs is ~ 3.12 eV. Therefore, the proposed method of fabricating TAT-NWs on glass and flexible ITO-coated PET substrates using the GLAD technique may be applicable for developing novel photoanode for dye-sensitized solar cells (DSSCs) and other optoelectronic applications.

Effect of Molybdenum Disulfide on the Performance of Polyaniline Based Counter Electrode for Dye-Sensitized Solar Cell Applications

Dye-sensitized solar cells are gaining interest in the aerospace industry, extending their applications from solar-powered drones to origami-style space-based solar power stations due to their flexibility, light weightiness, and transparency. The major issue with its widespread commercial use is the employment of expensive Pt-based counter electrodes. In this study, an attempt has been made to replace the Pt with Polyaniline (PANI)/Molybdenum sulfide (MoS2) nanocomposite. The nanocomposites i.e., PANI-0.5wt% MoS2, PANI-2wt%MoS2, PANI-5wt%MoS2, and PANI-7wt%MoS2and PANI-9wt%MoS2, have been synthesized and compared with standard Pt-based CE. Scanning electron microscopy, transmission electron microscopy, and X-ray diffraction methods have been utilized to study both surface morphology and structural composition. Fourier transform infrared has also been used to identify redox-active functionalities. Electron impedance spectroscopy and cyclic voltammetry have been employed to study electron transfer and catalytic activity. Finally, I-V testing has been conducted using a sun simulator. A maximum efficiency of 8.12% has been observed with 7wt% MoS2 in the PANI matrix at 6 µm thickness, which is 2.65% higher compared to standard Pt-based CE (7.91%). This is due to high electronic conduction with the addition of MoS2, improved catalytic activity, and the high surface area of the PANI nano-rods.

Synthesis and characterization of Fe-doped TiO2 hollow spheres for dye-sensitized solar cell applications

Fe-doped TiO2 hollow spheres (THs@Fe) with various Fe contents, 0, 0.25, 0.50, 0.75 and 1.00 mol%, were prepared using carbon templates and further employed as photoanode for dye-sensitized solar cells. The analytical results indicated that the hollow structure of THs@Fe promoted an effective light penetration and scattering capability, which resulted in increased light-harvesting efficiency. The increase in specific surface area and pore volume caused enhancement of dye molecules adsorbed on the photoanodes, which directly affected the performance of the DSSCs. The highest power conversion efficiency, 6.025 ± 0.141%, was obtained from 18NR/THs@0.25Fe bilayer photoelectrodes with a JSC of 15.392 ± 0.458 mA cm−2, VOC of 0.759 ± 0.001 V, and FF of 0.516 ± 0.018. The highest achieved PCE value was attributed to formation of oxygen vacancies and other defect states generating the shallow electron traps that are essential for charge transport, electron lifetime and resulted in the DSSCs performance.

Serrated hexagonal ZnO Nanoparticles: Synthesis and its characterization

ZnO nanoparticles with serrated hexagonal morphology were synthesised via hydrothermal route. XRD plot affirms the ZnO nanoparticles are formed. FTIR was performed to study the various vibrational modes of the synthesised ZnO nanoparticles. UV–VIS spectra was recorded to calculate the energy band gap of ZnO nanoparticles. Electrochemical studies were performed via Electrochemical Impedance Spectroscopy and Cyclic voltammetry techniques that shows the synthesised nanoparticles are appropriate for the application in Dye-sensitized solar cells.

Structural, morphological, and optical studies of hydrothermally synthesized Nb-added TiO2 for DSSC application

Herein, titanium dioxide (TiO2) nanoparticles doped with various concentrations (0–7 wt %) of niobium (Nb) are hydrothermally synthesized and used effectively as a photoelectrode for application in dye-sensitized solar cells (DSSCs). The rutile-to-anatase phase transition, accompanied by a change in crystallite size from 23.75 to 9.77 nm, is confirmed via X-ray diffraction (XRD) and Fourier transform (FT)-Raman spectroscopy. In addition, the prepared Nb–TiO2 nanoparticles exhibit a spherical morphology with a mean grain diameter of 43.38–50.69 nm. Further, X-ray photoelectron spectroscopy (XPS) indicates a shift in the Fermi level of the TiO2 towards the conduction band minimum, and an increase in the bandgap from 2.69 to 2.88 eV, with increasing Nb concentration. The resulting increases in the short-circuit current density (JSC) and open circuit voltage (VOC) with the increased injection and conductivity of electrons lead to the enhancement of the DSSC performance. EIS measurements represents the effect of Nb doping on charge transporting and recombination behavior of DSSCs. Moreover, the Nb–TiO2-based DSSCs provide a better power conversion performance as compared to that of the pristine TiO2.

Theoretical design of D-π-A system new dyes candidate for DSSC application

Currently, dye-sensitized solar cells (DSSCs) are one of the energy technologies that has piqued the interest of researchers, due to their distinct characteristics such as excellent air stability, ease of synthesis and photovoltaic properties interesting. This work aims to study the optoelectronic properties and photovoltaic of six organic dyes based on phenothiazine (PTZ). The effects of bridging core modifications of recently synthesized PSB-4(R) molecule on structural, photovoltaic, electronic, and optical properties of D1-D6 are studied. Using the method Density Functional Theory (DFT) level of the B3LYP (Becke three-parameter Lee–Yang–Parr) exchange correlation functional with 6-31G (d, p) and time-dependent DFT (TD-DFT). According to the obtained results, optoelectronic properties and photovoltaic of the dyes, we can suggest that these designed molecules are better sensitizers as a candidate for the production of dye solar cells (DSSCs). This theoretical study paves the way for chemists to synthesize more efficient sensitizers for applications in dye solar cells.

Co‐sensitization of 4‐(thiophene‐2‐ylmethylene)thiazolidin‐5‐one dyes with Ru(II) complex N‐719

Five novel co‐sensitizers IS‐8 to IS‐12 were synthesized to study their effect on the co‐sensitization with standard Ru(II) dye (N‐719). These effective co‐sensitizers (IS‐8 to IS‐12) include 3‐phenyl‐4‐(thiophen‐2‐ylmethylene)thiazolidin‐5‐one linked with malononitrile (IS‐8), ethyl cyanoacetate (IS‐9), 2‐cyano‐N‐phenylacetamide (IS‐10), 4‐(2‐cyanoacetamido)benzoic acid (IS‐11), and 2‐cyano‐N‐(4‐nitrophenyl)acetamide (IS‐12). From the obtained results, all co‐sensitizers possess thermodynamic requirements for dye‐sensitized solar cell applications (DSSCs). Their photovoltaic studies were evaluated through the device fabrication. Over co‐sensitization with N‐719, all co‐sensitizers enhance the photovoltage of N‐719. Further, N‐719 co‐sensitized with IS‐11 and IS‐12 performed power conversion efficiency of 8.32% and 8.09%, respectively, higher than N‐719 only, which performed 7.74% only. The higher photovoltaic performance of these co‐sensitizers may be attributed to maximum JSC values. The results ameliorate the role of efficient co‐sensitizers to yield DSSC with improved performance.

Dye Anchoring on CuCrO2 Surfaces for p-Type Dye-Sensitized Solar Cell Applications: An Ab Initio Study

The possibility of stably anchoring dye molecules on the exposed surface of a p-type semiconductor is crucial to have efficient dye-sensitized photoelectrodes. Here, we theoretically characterize the adsorption mechanism of carboxylic and phosphonic anchoring groups onto the (012) surface of stoichiometric and reduced CuCrO2 delafossite. Density functional theory is employed to accurately predict the preferred adsorption modes and their energies, both in the gas phase and solution (water and acetonitrile). On the stoichiometric (012) surface, we found a strong selectivity toward molecular monodentate binding modes at the highly active Cr-sites, stabilized by strong hydrogen bonds with the surface oxygens, for both anchoring groups; deprotonated bidentate bridging anchoring is only identified when the proton transferred to the surface is kept far away from the molecule during the structural relaxation process. On the other hand, the bidentate anchoring becomes the preferred adsorption mode when Cu+ vacancies are considered at the topmost layer of the surface slab. The identification of stable bidentate bridging anchoring modes on the CuCrO2 surface might have important implications for the device stability as well as for the efficiency of the interfacial hole injection and suggest it as an alternative material to NiO for p-type dye-sensitized solar cells.

Single-layer graphene-TiO2 nanotubes array heterojunction as photoanode to enhance the photoelectric of DSSCs

Photoanode optimization of the dye-sensitized solar cell (DSSC) is a crucial way to improve efficiency. In this investigation, a kind of heterojunction fabricated based on TiO2 nanotubes and graphene by wet transfer method, furthermore, the heterojunction was fabricated as photoanode of DSSC. This method has the advantages of simple operation and time-saving, and micromorphological characterization revealed that graphene and TiO2 combined well. UV–Visible diffuse-reflectance spectrum and photon-to-current conversion efficiency (IPCE) data demonstrated that the graphene transfer enhanced the cell's absorbance in the visible range and reduced the bandgap. The J-V curve was obtained under solar simulation, and the conversion efficiency of 4.18% was reached, which is 83% higher than that of graphene free cell. Therefore, the heterojunction of graphene/TiO2 nanotubes makes a promising prospect for further applications in DSSCs.

Molecular engineering of narrow bandgap porphyrin derivatives for highly efficient photothermal conversion

Organic dyes based on porphyrin derivatives have been widely reported to show promising application in dye-sensitized solar cells and organic solar cells due to their desired power conversion efficiency and extinction coefficient while their photothermal conversion performance is rarely reported, to date. Considering the design guideline of photothermal materials with wide near-infrared region absorption and large extinction coefficient, we designed and prepared a narrow bandgap donor-acceptor small molecule P(DPP)4 based on porphyrin and diketopyrrolopyrrole, which showed a photothermal efficiency of 73.2% under irradiation of 808 nm laser, due to its aggregation-induced radical and distinct nonradiative decay. Furthermore, in an interfacial-heating water evaporation system, P(DPP)4 exhibited an evaporation rate of 1.304 kg m−2 h−1 under 1 sun irradiation with a solar-energy-to-vapor efficiency of 90.6%, higher than most of the pure organic photothermal materials. This work provides a promising way for organic small molecules as solar absorbers with high solar-thermal conversion efficiency and reveals the great potential of organic semiconductors with aggregation-induced radical in photothermal materials.

High-efficiency quasi-solid state dye-sensitized solar cells using a polymer blend electrolyte with “polymer-in-salt” conduction characteristics

“Polymer-in-salt” electrolytes are special conductive materials that demonstrate much higher conductivity compared to the conventional “salt-in-polymer” electrolytes. However, up-to-now, they are found unsuitable for dye-sensitized solar cells (DSSCs) application, mainly because they lead to increased charge recombination rate. The present paper demonstrates the development and application in DSSCs of polymer blend electrolytes that utilize features found in “polymer-in-salt” electrolytes, while the aforementioned drawback is overcome. This is done with the appropriate selection and amount of polymers used to jellify the liquid state electrolyte, keeping the redox couple concentration fixed at a high level. Herein, the unique properties of polyvinylpyrrolidone (PVP), as a nitrogen-containing heterocyclic polymer, in combination with the ability of polyethylene glycol (PEG) to dissolve high quantities of ionic compounds, were the main reasons for developing PVP/PEG blend-based polymer electrolytes for DSSCs. The efficiency attained by the solar cells employing the polymer blend electrolytes was found enhanced up to 30% compared to the corresponding of DSSCs employing the PVP-based and PEG-based polymer electrolytes. By the extra use of two common additives in the best-performing polymer blend electrolyte and an advanced multi-layered photo-anode, the efficiency of DSSCs reached 8.21%, which is one of the highest reported for quasi-solid state DSSCs employing non-composite ionic liquid-free iodide-based polymer electrolytes. The results are also found quite satisfactory compared to the corresponding ones obtained by the DSSCs employing commercially available liquid state electrolytes, while the preparation of the proposed electrolytes is simple and of low-cost, and their composition has great prospects for further improvement.

New 3-Ethynylaryl Coumarin-Based Dyes for DSSC Applications: Synthesis, Spectroscopic Properties, and Theoretical Calculations.

A set of 3-ethynylaryl coumarin dyes with mono, bithiophenes and the fused variant, thieno [3,2-b] thiophene, as well as an alkylated benzotriazole unit were prepared and tested for dye-sensitized solar cells (DSSCs). For comparison purposes, the variation of the substitution pattern at the coumarin unit was analyzed with the natural product 6,7-dihydroxycoumarin (Esculetin) as well as 5,7-dihydroxycomarin in the case of the bithiophene dye. Crucial steps for extension of the conjugated system involved Sonogashira reaction yielding highly fluorescent molecules. Spectroscopic characterization showed that the extension of conjugation via the alkynyl bridge resulted in a strong red-shift of absorption and emission spectra (in solution) of approximately 73–79 nm and 52–89 nm, respectively, relative to 6,7-dimethoxy-4-methylcoumarin (λabs = 341 nm and λem = 410 nm). Theoretical density functional theory (DFT) calculations show that the Lowest Unoccupied Molecular Orbital (LUMO) is mostly centered in the cyanoacrylic anchor unit, corroborating the high intramolecular charge transfer (ICT) character of the electronic transition. Photovoltaic performance evaluation reveals that the thieno [3,2-b] thiophene unit present in dye 8 leads to the best sensitizer of the set, with a conversion efficiency (η = 2.00%), best VOC (367 mV) and second best Jsc (9.28 mA·cm−2), surpassed only by dye 9b (Jsc = 10.19 mA·cm−2). This high photocurrent value can be attributed to increased donor ability of the 5,7-dimethoxy unit when compared to the 6,7 equivalent (9b).