Photoanodes For Dye-sensitized Solar Cells Research Articles

Enhanced performance of Mg and La co-doped TiO2(98%)−ZrO2(2%) photoanode for dye-sensitized solar cells

Abstract This study explores the effects of magnesium (Mg) and lanthanum (La) doping on the performance of dye-sensitized solar cells (DSSCs) utilizing TiO2(98%)−ZrO2(2%) (TZ, TZM, and TZL) photoanodes. The photoanodes were fabricated using a spin-coating sol–gel method, followed by calcination at 400°C. The structural, morphological, crystallographic, and optical properties of the proposed photoanode composites were characterized by X-ray diffraction, transmission electron microscopy, and ultraviolet–visible spectroscopy. The crystallite sizes of the synthesized thin films varied from 21.16 to 59.04 nm for the TZ, TZM, and TZL compositions. The current–voltage measurements of DSSCs based on TZL8 photoanode, cobalt sulfide-doped graphene counter electrode, and N719 dye revealed the highest efficiency of nearly 5.052%. The assembled DSSCs exhibited an open-circuit voltage of 0.74 V, a short-circuit current density of 9.964 mA/cm2, and a fill factor of 0.685. The enhancement in open-circuit voltage and short-circuit current density could be attributed to the improved electronic and microstructures of the proposed photoanodes.

Rational Design of Facile and Low‐Cost Construction of Carbon‐Based Dye‐Sensitized Solar Cells using Garcinia Mangostana L. as a Photosensitizer

Research on solar cell devices is not only always related to how to obtain high power conversion efficiency (PCE), but also other factors need to be fully considered, such as the cost and their ecofriendliness. In this present research, a low‐cost and ecofriendly dye‐sensitized solar cell (DSSC) is being developed using a graphite‐based nanocomposite and an unusual plant extract (Garcinia mangostana L.) as the dye photosensitizer. A rational design on how to use graphite as a photoanode and counter electrode (CE) in DSSC is carried out by combining the graphite with ZnO and multiwalled carbon nanotube (MWCNT), respectively. It is observed that graphite acts as a matrix for ZnO and MWCNT to make these nanocomposites have very appropriate optoelectronics and catalytic properties compared to the control sample. Therefore, they could serve as an excellent photoanode and CE, respectively. It is also expected that the anthocyanin absorption in Garcinia mangostana L. dye which is found in the visible light range can efficiently absorb photons, thus supporting the enhancement of photovoltaic performance of the DSSC. The generated voltage (V) and current (I) from light irradiation using commercial lamps are higher compared to halogen lamps, indicating that the obtained DSSC has potential as indoor powered devices. It is believed that our study can shed light on the development of DSSC using low‐cost material graphite as the main component for the realization of low‐cost DSSC devices.

Far-red active squaraine dye-sensitized photoanode for dye-sensitized solar cells with a copper (II/I) electrolyte

In dye-sensitized solar cells (DSSC), controlling the dye-aggregation on TiO2 and charge recombination between electrons present in TiO2 and electrolyte can be achieved by wrapping the long alkyl groups around the dye structure and further introducing bulky donor on the dye is a potential approach to enhance both the open-circuit potential and short-circuit current parameters. Additionally, bulky donor containing dye structures modulates the photophysical and electrochemical properties of the sensitizer which helps reducing the over potentials required for the dye regeneration process by utilizing a multidentate ligand containing [Cu(tme)]2+/+ and I−/I3− redox electrolytes. Hagfeldt donor appended far-red NIR active unsymmetrical squaraine dye (SQ-HF) has been designed, synthesized, and characterized. SQ-HF dye showed an intense absorption at 676 nm (ε 1.7 × 105 M−1cm−1). Photophysical and electrochemical studies indicated that the LUMO and HOMO energy levels of the SQ-HF dye were suited for charge injection (from the LUMO of the dye to the conduction band of TiO2) and dye-regeneration processes, respectively. The DSSC device efficiency of 5.15 % (JSC of 10.83 mA/cm2 and VOC of 0.690 V) has been achieved for SQ-HF dye by utilizing a literature reported [Cu(tme)]2+/+ and 4.11 % (JSC of 8.74 mA/cm2 and VOC of 0.702 V) in I−/I3− redox shuttles, respectively.

Enhanced efficiency, electron lifetime, and eco-friendliness of dye-sensitized solar cells using nanofibrous TiO2/ZnO composite photoanodes and natural anthocyanin sensitizer

Semiconductor is the main part of the photoanode in dye-sensitized solar cells (DSSCs). In this study, an evaluation was conducted on two different morphological shapes of TiO2/ZnO semiconductors, namely nanoparticles (NPs) and nanofibers (NFs), to enhance the efficiency of DSSCs. The nanofibrous semiconductors were fabricated using the electrospinning technique. Furthermore, a natural sensitizer, anthocyanin dye, was used to promote the environmental friendliness of the fabricated cells. These cells were then compared to those that used a synthetic dye known as N719 to determine their efficiencies. The UV-vis results confirmed the extraction of anthocyanin from black plum fruits (Syzygium cumini). The structural characteristics of the composites were examined using XRD, FE-SEM, and BET experiments. The XRD results revealed that the anatase phase of TiO2 was dominant in the crystal structure of the semiconductors, while the crystallite sizes of the composites were 25.04 nm and 12.24 nm in NPs and NFs forms, respectively. The FE-SEM analysis revealed the formation of quasi-spherical NPs with an average diameter of 48.26 ± 17.75 nm and NFs with an average diameter of 153.99 ± 26.18 nm. The BET results showed that the surface characteristics of the nanocomposite were enhanced by changing the shape from NPs to NFs. Photovoltaic studies showed that utilizing NFs semiconductors in the photoanodes of DSSCs resulted in increased conversion efficiency of light to electricity. The results of the sun simulator studies confirmed that the use of natural dye led to a decrease in the effectiveness of the DSSCs. This phenomenon can be attributed to the weaker binding of the natural dye to the photoanodes. Furthermore, the EIS investigations illustrated that the electron lifetime in the natural dye is more than twice that of N719, leading to a reduced rate of electron recombination in the Syzygium cumini extract. The TiO2/ZnO NFs photoanodes exhibited superior performance compared to their nanoparticle counterparts in DSSCs. Their high surface area promoted superior dye adsorption and light absorption. Moreover, the interconnected nanofiber network facilitated efficient electron transport, minimizing recombination losses. Increasing the binding strength of the chosen natural dye to the photoanode will also make the cells more environmentally friendly and improve their ability to produce electricity.

Enhancing Efficiency of Dye-Sensitized Solar Cell using Mn or Ce Doped and Co-doped ZnO Photoanodes with Lawsonia Inermis Natural Dye

Abstract In the present research paper, Mn (transition metal) and Ce (rare earth metal) doped and co-doped ZnO nanoparticles were synthesized using a cost-effective sol-gel technique. As synthesized samples were characterized using X-ray diffraction and field emission scanning electron microscope to examine the structure and morphology respectively. The optical properties were examined by UV-Visible and photoluminescence spectroscopic techniques. The synthesized samples were used as photoanode for the fabrication of dye-sensitized solar cell (DSSC). The utilization of a photoanode, containing Mn and Ce doped and co-doped in ZnO, in DSSC leads to a significant enhancement in photovoltaic conversion efficiency with natural dye lawsonia inermis. Different combinations of Mn or Ce doped and co-doped ZnO nanoparticles were used for testing their effectiveness as photoanode in DSSC. It was observed that the efficiency for Mn and Ce co-doped ZnO photoanode-based DSSC was found to be 0.2118%, which is approximately a 750% increase as compared to bare ZnO photoanode based DSSC. The enhancement in the efficiency of DSSCs was due to the formation of a blocking layer by Mn ions which helps to stop the flow of electrons backward and the broadening of the spectrum region with the help of Ce ions using up/down conversion process also helps to achieve higher efficiency. This enhancement in the efficiency of DSSC may be attributed to the synergic effect of Mn and Ce.

Evaluation of TiO2 nanotubes decorated with Ag nanoparticles and photosensitized with grape skin extracts as a potential photoanode for dye-sensitized solar cells

Evaluation of TiO2 nanotubes decorated with Ag nanoparticles and photosensitized with grape skin extracts as a potential photoanode for dye-sensitized solar cells

Synergistic effects of Co-Mn co-doping on the structural and optical properties of TiO2 nanospheres: Dual functions for DSSC photoanodes and degradation photocatalyst

Synthesizing direct solar irradiance-responsive nanomaterial capable of serving as an efficient photoanode for dye-sensitized solar cells (DSSCs) and active photocatalysts for organic pollutant elimination poses a formidable challenge. This study focused on the synthesis of cobalt and manganese co-doped titanium dioxide (TiO2) nanoparticles via sol-gel technique, enhancing their efficacy in both the DSSCs and methylene blue (MB) dye degradation. X-ray diffraction and Raman analysis confirm the existence of a tetragonal crystal structure with the anatase phase of TiO2, while XPS analysis verifies the successful integration of cobalt and manganese ions into the host lattices. BET analysis has confirmed that Co, Mn co-doped TiO2 exhibits a higher pore volume and specific surface area compared to the undoped TiO2 material. FESEM and HR-TEM reveals spherical shape morphology and EDS mapping confirms the purity of synthesized nanoparticles. Moreover, Co-Mn co-doped TiO2 nanoparticles exhibits a shift in the optical absorption edge towards the visible spectrum in UV-DRS analysis. PL analysis suggests a diminished electron-hole recombination within the doped and co-doped sample. Electrochemical impedance spectroscopy demonstrates improved charge transfer properties. DSSCs employing the co-doped TiO2 exhibit significantly enhanced power conversion efficiency (4.99 %) compared to bare TiO2 (2.03 %), cobalt-doped (2.61 %), and manganese-doped TiO2 (3.97 %). Additionally, it demonstrates exceptional photocatalytic activity, with 87.83 % (Co-Mn co-doped TiO2) degradation efficiency with a lesser time extent for the methylene blue dye degradation. These findings underscore the potential of Co-Mn co-doped TiO2 for addressing dual challenges in renewable energy (DSSC) and environmental remediation (Pollutant removal).

Simulation Studies of Interfacial Kinetics of Dye-Sensitized Solar Cells Photoanodes in Scanning Electrochemical Microscopy

Approach curves in the feedback mode of scanning electrochemical microscopy (SECM) were simulated for photoanodes in dye-sensitized solar cells by finite element simulation using COMSOL Multiphysics and compared to experimental data for the sample set with varying the photoanode film thickness (ZnO, cobalt mediator, organic dye). This reveals quantitatively the effect of the mass transport limitation of the mediator diffusion and organic dye regeneration kinetics in the mesoporous photoanode. The simulation of the mesoporous material was made with a pseudo-homogeneous approach in two space dimensions.The simulation allows to extract the maximum information content from the experimental data. The light adsorption was treated as exponential decay of intensity within the photoanode (Lambert-Beer law), electron injection in the conduction band of ZnO photoanode and loss mechanism was explicitly considered. The light illumination is homogeneous over the entire simulation domain of 1 mm in diameter. Just like in the experiment, the built geometry used for the simulation has a conducting blocking layer (0.6 µm in thickness) to prevent the recombination of electrons with the back contact. The porous dye-sensitized layer has a porosity of 50 - 60% and a thickness of 1- 10 µm. The inner surface holds the dye for absorbing light. The mediator diffuses in the pore of the photoanode (internal solution) and in the bulk of the electrolyte (external diffusion). The transparent conducting glass makes the boundary of the simulation domain. The electrolyte-platinum contact is not modelled. The selected boundary conditions are equivalent to the short-circuit operation of the cell.Interestingly, the simulation suggests that built meshes which had earlier been used for porous electrode simulation could not adequately describe the electron concentration profile for thinner electrodes despite providing a correct ME electrode current for limiting cases. The mesh convergence analysis studies were made to optimize the mesh to reduce computation time and memory size. The electrons in the conduction band were quantitatively determined because transport in the semiconducting photoanode is primarily driven by a thermally activated trapping-untrapping mechanism that can be described by transport equations similar to Fick's laws.The unknown parameters (dye absorption coefficient and recombination rate constant) were adjusted to ensure various light intensities in the simulation correspond to the experiment. An accurate description of the electrons within the semiconductor is critical for explaining the time-dependent behavior of the dye-sensitized photoanode in SECM approach curves. After obtaining agreement with experimental approach curves under steady-state conditions, the same parameters are used to study the current transient obtained under intermittent illumination.

Evaluation of Dye Loading on Photoanodes of Dye-Sensitized Solar Cells Utilizing a Mixture of TiO2 and Magnesium/Aluminum Layered Double Hydroxide (LDH)

Evaluation of Dye Loading on Photoanodes of Dye-Sensitized Solar Cells Utilizing a Mixture of TiO2 and Magnesium/Aluminum Layered Double Hydroxide (LDH)

Barium titanate nanorods/nanoparticles embedded reduced graphene oxide nanocomposite photoanode for dye-sensitized solar cell

Perovskite barium titanate nanorods/nanoparticles (BaTiO3 NRs/NPs) and reduced graphene oxide loaded barium titanate nanocomposite (BaTiO3 NRs/NPs-rGO NC) were synthesized by hydrothermal method and applied as photoanode materials in dye-sensitized solar cell (DSSC). The prepared perovskite nanomaterials were characterized by SEM, HRTEM, EDAX, XRD, XPS, PL and Raman techniques. The photovoltaic performance of DSSC fabricated using BaTiO3 NRs/NPs-rGO NC photoanode delivered a highest PCE of 5.92 %, which was almost twofold higher than the PCE of BaTiO3 NRs/NPs photoanode based DSSC (3.07 %). This improved photovoltaic performance could be attributed to superior light-harvesting and charge transportation behaviour of BaTiO3 NRs/NPs-rGO NC photoanode.

Investigation of structural, optical, surface, electrochemical and corrosion properties of ZnO and AZO nanorod arrays for dye absorption applications

In dye-sensitized solar cells (DSSC), photoanodes have special importance in the processes of dye support, photon absorption and electron transport. ZnO nanorod arrays are promising photoanode materials, but their properties need to be improved by innovative fabrication approaches to improve the performance of ZnO-based DSSCs. In this study, pure and Al-doped ZnO (AZO) nanorod arrays were grown by hydrothermal method onto ZnO seed layers produced by sol-gel spin coating. As far as we know, for the first time in the literature, HMTA-HMDA ligand mixture was used instead of HMTA in the preparation of hydrothermal precursor solutions. To investigate the potential use of ZnO and AZO nanostructured films as photoanodes in DSSCs; their surface, structural and optical properties were examined. Additionally, charge transfer kinetics, corrosion resistance and dye loading capacities were determined by advanced analyzes such as electrochemical impedance spectroscopy, potentiodynamic polarization and adsorption-desorption methods. The supporting HMDA ligand and Al impurity used in the preparation of hydrothermal precursor solutions led potential usages as photoanode of ZnO nanorod arrays to increase by improving their structural, optical, surface, and electrochemical properties, corrosion resistance and dye loading capacities.

Design and fabrication of layered TiO2/rGO composited photoanode and its photovoltaic performance regulation for dye-sensitized solar cells

To improve the photovoltaic performance of the traditional TiO2 photoanode for dye-sensitized solar cells (DSSCs), a series of layered TiO2/rGO composited DSSCs photoanode was assembled by changing the morphologies of the TiO2 and introducing reduced graphene oxide (rGO) into different areas of the photoanode films. Firstly, TiO2 nanoflowers (TiO2-NFs), TiO2 nanorods (TiO2-NRs) were prepared employing the hydrothermal method and used as photoanode materials to explore the synergistic effect of TiO2 with different morphologies in layered photoanode. Then, TiO2-NFs/rGO composited photoanode (TNF/rGO) were fabricated to research the mechanism of rGO on improving electron transmission in the layered photoanode. The effect of adding rGO at different parts of the layered photoanode on the performance of DSSCs was also investigated. Attributing to the enhancement of light absorption and charge transfer, a champion power conversion efficiency (η) of 9.21 % (Jsc = 23.36 mA cm−2, Voc = 0.74 V, FF = 0.53) was achieved with the layered TiO2/rGO composited photoanode containing two consecutive layers of TiO2-NFs/rGO and P25/rGO, which exhibited an 82.01 % increase than traditional TiO2 (pure P25) photoanode (η = 5.06 %, Jsc = 12.09 mA cm−2, Voc = 0.73 V, FF = 0.58). It is an effective way to design and fabrication of layered TiO2/rGO composited photoanode to regulate the photovoltaic performance of traditional TiO2 photoanode for DSSCs based on the synergistic effect of its multi-layer structure, TiO2 morphologies and introduction of rGO.

Fabrication of binder-free TiO2 P 25 films on flexible PET/ITO substrate for photoanode in dye-sensitized solar cells

In this work, TiO2 P 25 films for photoanode in dye-sensitized solar cells (DSSCs) have been fabricated using a flexible PET/ITO substrate with a low-temperature heating technique. Ammonium hydroxide/ethanol solution was used as an alternative binding agent to fabricate TiO2 paste, which can be removed at low-temperature heating. The conventional screen print method is still used in DSSC fabrication because it is a very cheap and easy technique. A hot-pressing method is also used to improve the quality of TiO2 films and the performance of DSSCs. The encapsulation technique used in the assembly of DSSC is expected to increase the stability of DSSC devices to prevent electrolyte leakage. The resulting TiO2 film shows the highest DSSC performance using the hot-pressing and encapsulation method with PCE 0.29%. The encapsulation technique increased the stability of DSSC devices with more extended durability than without encapsulation.

Study of the Optical and Structural Properties of Metal-Doped Titanium Dioxide Electrode Prepared by the Sol-Gel Method for Dye-Sensitized Solar Cells

This study presents a strategy to increase the efficiency of dye-sensitized solar cells (DSSCs) by doping titanium dioxide (TiO2) with different magnesium (Mn) concentrations (1, 3, 5, 7, and 9%) generated by the sol-gel process and effectively employed as a photo-anode (the working electrode) for DSSCs. The Doctor Blade method coated the indium-doped tin oxide (ITO) glass with a thin film layer. X-ray diffraction (XRD) was used to evaluate the characteristics of undoped and manganese-doped TiO2, and the results demonstrate that all of the thin films are anatase. The samples were examined using XRD to assess grain size before and after Mn doping. The spectrum of UV-Vis absorption changes; accordingly, as doping increases, the energy gap decreases. The smallest energy gap's value (2.4 eV) is 7% manganese doping. AFM pictures show the average roughness and root mean square of the weight percentage of films doped with 5%. Field effect scanning electron microscope (FE-SEM) studies show that the particle size of thin films gets smaller as more Mn is added, which happens at least as much as 7% Mn doping. The optimal thickness for TiO2 paste over conductive glass is 15 μm, and the cell's power conversion efficiency increased to 0.604074% with an Imax of 4.965 mA, a Vmax of 0.488 V, and a fill factor (FF) of 68.45954%.

Bio-cellulose-derived rGO-supported SmCoO3 hybrid composite photoanode for high performance dye-sensitized solar cells

Bio-cellulose-derived rGO-supported SmCoO3 hybrid composite photoanode for high performance dye-sensitized solar cells

Synthesis of TiO2 nanoparticles by green approach: Application as photoanode for dye-sensitized solar cells

Efficient photoanodes play a central role in the performance of dye-sensitized solar cells. Traditional methods for synthesizing TiO2 often involve chemical processes that can be expensive and environmentally harmful due to the use of toxic and hazardous substances. Therefore in this work, TiO2 nanoparticles (NPs) were synthesized using bio-inspired processing through a hydrothermal procedure using different concentrations of Aloe barbadensis miller leaves extract as the reducing and stabilizing agent. Scanning electron microscopy (SEM), UV–vis spectroscopy (UV), X-ray difraction (XRD), Raman Spectroscopy, transmission electron microscopy (TEM) and Brunauer–Emmett–Teller (BET) analysis were used to characterize as synthesized TiO2 NPs. DSSCs were fabricated employing the prepared TiO2 NPs as photoanodes, and their performance was assessed. DSSC generates JSC of 9.7 mA/cm2, VOC of 0.682 V and efficiency (η) of 4.3 % when 20 mL concentration of extract was used for the synthesis of TiO2 NPs and subsequently their photoanodes.

Design of highly efficient 0D/1D TiO2 photoanode for dye-sensitized solar cells by simple TiCl4 pre-treatment of titanate nanotubes

Dye-sensitized solar cells (DSCs) represent a promising avenue for sustainable energy conversion, with the efficiency of these devices heavily reliant on the performance of the TiO2 photoanode. Despite significant advancements, optimizing the photoanode material for higher efficiency remains a challenge. This study introduces a novel approach to constructing a highly efficient, multifunctional 0D/1D TiO2 composite by simply pre-treating the TiO2 precursor, specifically one-dimensional (1D) H-titanate nanotubes, with TiCl4. The TiCl4 treatment not only encourages the extensive synthesis of the one-dimensional nanostructures (i.e., nanorods) but also facilitates the in situ hydrolysis to generate small crystals that attach to the surface of the nanorods. The TiO2 composite offers several essential benefits, including the expanded thickness, high surface area for superior dye adsorption, efficient diffuse light scattering induced by the aggregate structures, and fast charge transport within the film matrix, making it an exemplary component for DSCs. The photovoltaic performance test revealed that TiCl4 pre-treatment increased power conversion efficiency by 36.3 %, rising from 7.63 % of untreated cells to a striking value of 10.4 %, which is a new record when N719 is used as a sensitizer and iodide-based redox shuttle employed as an electrolyte. This research provides an effective strategy for developing highly efficient photoanode material for DSCs.

Fabrication, characterization and application of W/N co-doped zinc oxide nanoparticles as a promising photoanode for dye-sensitized solar cells

In the present investigation, undoped, W doped, and W/N co-doped ZnO nanoparticles were prepared by sol–gel route. Here, the ZnO layers were fabricated via the doctor blade method. Hexagonal wurtzite structure is determined by XRD studies. The formation of a hexagonal wurtzite structure was observed from X-ray powder diffraction (XRD) resulting in a slight increase in crystallite size with an increase in doping content. The UV observation shows that W/N co-doping shifted the absorption spectra towards a higher wavelength and reduces the band gap energy. The EDS spectra confirms the high purity and triumphant doping of the W(tungsten) and N(nitrogen) into the ZnO lattice. The morphology of undoped and W/N co-doped ZnO nanoparticles was demonstrated by using FESEM and HRTEM. The 2 % W and 1.5 % N co-doped ZnO photoanode based DSSC (dye-sensitized solar cells) gained the highest short circuit current density of 8.44 mAcm−2 having an open-circuit voltage of 0.65 V, and PCE (power conversion efficiency) of 3.60 %.

Improvement of the photoelectric dye sensitized solar cell performance using Fe/S–TiO2 nanoparticles as photoanode electrode

A sulfur nanoparticles-incorporated iron-doped titanium oxide (Fe/TiO2) with different ratio was successfully synthesized by photolysis method and utilized as effective photoanode in dye sensitized solar cell (DSSC) application with N719 dye. The photolysis method was contained the irradiation of the Fe, S and Ti mixture solution with 15 W source irradiation, and then calcined the formed precipitate. The DSSCs fabricated with Fe/S–TiO2 photoanode appeared an improved solar-to-electrical energy conversion efficiency of 6.46, which more than pure TiO2 (3.43) below full sunlight illumination (1.5 G). The impact of Fe content on the total efficiency was also inspected and the Fe content with 6% S–TiO2 was found 5 wt%. Due to the improved the efficiency of solar cell conversion of Fe/S–TiO2 nanocomposite, it should be deemed as a potential photoanode for DSSCs with high performance.

Photoanode Modification Based on Lignin Extracted from Rice Husk for Dye-Sensitized Solar Cells

The photoanode optimization of dye-sensitized solar cells (DSSCs) has been developed to create renewable devices based on green chemistry. TiO2 plays a crucial role in light absorption, charge separation, and electron transport within the photoanode of DSSCs. Modifying mesoporous TiO2 photoanode using lignin-template has been considered a viable option for photocatalyst synthesis. Lignin derived from rice husk is a potential material due to its abundant sources in many countries. Therefore, in this work, rice husk lignin was employed for non-toxic and low-cost material performance improvement of TiO2. Experimental results showed that the best efficiency and current density were identified as the effect of adding a 5% concentration of lignin on the TiO2 composite, namely 4.81% PCE.