TiO2-based Dye-sensitized Solar Cells Research Articles

Use of new natural dyes extracted from different sections of Salvia urica in dye-sensitized solar cells

In this study, natural dyes that were obtained from the branches, flowers and leaves of Salvia urica were utilized as sensitizers in TiO2-based dye-sensitized solar cells (DSSCs). XRD and FE-SEM were used to analyze the crystal structure and morphological properties of the produced TiO2 nanopowders, respectively. The optical properties of natural dyes extracted from the Salvia urica plant were investigated by UV-vis spectroscopy. Functional groups in natural dyes were detected by FTIR spectroscopy, while DSSCs were evaluated for photovoltaic performance and electrochemical impedance. The findings show that the flower dye absorbs a wider wavelength of light in the visible region and the interaction between the carbonyl/hydroxyl groups and the TiO2 surface is very strong, which is why it is the most efficient way of power conversion among all other natural sensitizers. The efficiencies of DSSCs sensitized with flower, branch and leaf dye of Salvia urica were 0.33%, 0.28%, and 0.19%, respectively.

Optimization of preparation conditions by response surface methodology for synthesis of titanium dioxide/reduced graphene oxide composite in dye-sensitized solar cells

This study aimed to address the need for alternative materials in the anode layer to enhance the performance of dye-sensitized solar cells (DSSCs). The synthesis of titanium dioxide/reduced graphene oxide (TiO2/rGO) was carried out using the response surface methodology by face central composite design (RSM/FCC). This method allowed us to systematically evaluate the influence of two key factors, namely the weight percentage of precursor graphene oxide (GO wt%) and the L-ascorbic acid ratio, | on the power conversion efficiency (PCE) of DSSCs. Our research is significant because it explores the synthesis of TiO2/rGO as a novel material for the anode layer in DSSCs. This material holds promise for improving device performance due to its unique properties, such as enhanced charge transport and light harvesting capabilities. Additionally, TiO2/rGO can serve multiple functions within the DSSCs device, acting not only as a charge transport layer but also potentially as a light scattering layer to increase photon absorption. The statistical analysis revealed that the GO wt% had a more significant influence on PCE compared to the L-ascorbic acid ratio. Furthermore, our simulation results demonstrated high validity and accuracy, with a correlation coefficient (R2) of 0.9988 and a residual standard error of less than 5 %. The optimized DSSCs-based TiO2/rGO anode achieved a remarkable PCE of 7.12 %, representing a 29 % improvement compared to the pure TiO2-based DSSCs anode. In summary, our study highlights the importance of synthesizing TiO2/rGO as a novel material for the anode layer in DSSCs and demonstrates its potential for significantly enhancing device performance. This study emphasizes these key points more prominently in the abstract to better convey the novelty and significance of our findings.

A doped heterojunction photoanode: a strategy-driven approach to improve the charge carrier dynamics and photoconversion performance of the TiO2-based dye-sensitized solar cell

A doped heterojunction photoanode: a strategy-driven approach to improve the charge carrier dynamics and photoconversion performance of the TiO2-based dye-sensitized solar cell

Structural and Optical Characteristics of Multilayer ZnO Nanorod:TiO2 by DC Magnetron Sputtering for Dye Sensitized Solar Cell (DSSC) Application

The development of Dye-Sensitized Solar Cell (DSSC) technology by utilizing various semiconductors has attracted attention. Among all types of semiconductors, the nanostructure of ZnO is selected due to their unique electrical properties and ease of preparation in various morphologies, and it has been considered a promising material to be applied in DSSC. In this research, the DC magnetron sputtering method was used to prepare ZnO thin films as an efficient alternative to press the charge recombination process that occurs in TiO2-based DSSC. Different thicknesses of TiO2 layers on the FTO conductive glass substrate were made through various sputtering deposition times, while the ZnO nanorod layers were made with a single layer using the hydrothermal method. We used XRD, SEM, UV-Vis, I-V meter, and EIS analysis. Based on these characterization we concluded that multilayer ZnO nanorod:TiO2 coating with a sputtering time of 60 minutes resulted the best performance of DSSC with an efficiency of 0.27%.

Stability and efficiency improvement of TiO2-based dye-sensitized solar cells by surface modification of MgO

Stability and efficiency improvement of TiO2-based dye-sensitized solar cells by surface modification of MgO

A novel simplified approach in fabricating TiO2 photoanodes for dye-sensitized solar cells

Globally, the hydrothermal method is widely adopted in synthesizing TiO2 photoanodes for various applications, including dye-sensitized solar cells (DSSCs). Nonetheless, this method typically involves several synthesis steps, and most reported works were intricate and complex to follow. In this work, a reinvented novel methodology for hydrothermal synthesis was successfully developed. The mixed-phase of anatase-rutile TiO2 photoanodes was demonstrated by omitting several intermediate hydrothermal steps. Using the reinvented methodology, the DSSC devices presented a comparable and excellent power conversion efficiency (η = 3.30%) to commercial TiO2-based DSSCs (η = 3.81%). Hence, this preliminary study provided new perspectives toward simplifying wet chemical synthesis TiO2 techniques for the design structure of DSSCs.

Physicochemical properties of Fe-doped TiO2 and the application in Dye-sensitized solar cells

Fe-doped TiO2 was here used as a semiconductor material for Dye-sensitized solar cells (DSSCs) to improve the solar energy conversion to electricity as compared to precursor TiO2. The physicochemical properties of Fe-doped TiO2 were clarified by different techniques such as X-ray diffractions, Transmission Electron Microscope, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, UV–vis Diffuse Reflectance Spectra, and Photoluminescence Spectra. The material resulted in a defective TiO2 with oxygen vacancies and Ti3+ along with Fe ions into the structure. The formation of superficial defects contributed to the prevention of electron-hole recombination, thereby enhancing the lifetime of the photoelectrons. The presence of defects was measured by the deconvolution of Ti 2p and O 1s, while the low recombination rate was calculated with the PL spectrum of the semiconductor. The higher lifetime of the e−/h+ pairs lead to a result with the efficiency of Fe–TiO2-based DSSC increased to 30% in comparison with undoped-TiO2-based DSSC.

Efficiency enhancement of natural cocktail dyes in a TiO2-based dye-sensitized solar cell and performance of electron kinetics on the TiO2 surface

In this study, natural dye extracts were prepared from the dried leaves of Andrographis paniculata and Psidium guajava (APPG). The study’s objective was to increase the light harvesting phenomenon from solar energy utilizing natural dye from APPG, and the problem statement was to harvest the optimum solar radiation and convert it into electrical energy. Acetone and ethanol were used as solvents during the preparation process. Based on this research, the crystallite size of TiO2 nanoparticles was assessed, the impact of acetone and ethanol on APPG dye was compared, and the absorption, FTIR, and UV-Vis spectra of the solar cell fabrication process using solvents were experimentally explored. APPG leaf extract functions as a dye sensitizer. Cells are precisely sandwiched with a photoanode, TiO2 nanoparticles, an electrolyte (I/I3−), and a cathode. The JV properties of dye extracts utilizing acetone and ethanol were measured using a solar simulator equipped with a 100 mW/cm2 Xenon light and a Keithley 2400 Graphical Series SMU. An experimental DSSC with dye extraction and utilizing acetone solvent yielded a maximum photo-conversion efficiency of 0.6914%, while ethanol yielded a photo-conversion efficiency of 0.5630%. Furthermore, an energy-level diagram was used to explain the electron kinetics of DSSC, and the time required for transfer electron injection in the TiO2 surface from a dye-excited state was 150 ps.

Derivatized photosensitizer for an improved performance of the dye-sensitized solar cell

In recent years, Dye-Sensitized Solar Cell (DSSC) has drawn enormous attention due to its advantages over conventional silicon solar cells in terms of technological, financial, and environmental sustainability. In this work, experimental and computational methods were employed to investigate the effect of derivatization of dyes—cyanoacetic acid derivatives of cinnamaldehyde (HB1) photosensitizers on the performance of the TiO2-based DSSCs. The optical properties and the functional groups of the two dyes were determined by using UV–vis spectrophotometer and FT-IR spectroscopy, respectively. The J-V characterization and power-conversion efficiency of dyes in TiO2-based DSSCs containing I-/I3- electrolyte, and Graphite-carbon based FTO-glass (counter electrode) were examined. The study revealed that the HB1 (derivatized dye) was shown to improve the DSSC performance compared to cinnamic acid (underivatized dye). The HOMO-LUMO energy bandgap was estimated using the density functional theory density (DFT) tool as implemented in Gaussian09 software with a basis set of B3LYP/6-31G (d, p) level of theory. The bandgap of dyes before and after derivatization were found to be 4.93 and 3.73 eV, respectively, higher than the bandgap of TiO2 (3.2 eV). HB1 offers the highest VOC, JSC, fill factor (%FF), and power-conversion efficiency of 0.48 V, 0.19 mA/cm2, 0.61, and 0.50 %, respectively. The study found that the derivatization technique greatly improved the conversion efficiency of the DSSCs by about 22 % in comparison to the cinnamic acid dye (0.39 %).

Plasmon Effect of Ag Nanoparticles on TiO2/rGO Nanostructures for Enhanced Energy Harvesting and Environmental Remediation.

We report Ag nanoparticles infused with mesosphere TiO2/reduced graphene oxide (rGO) nanosheet (TiO2/rGO/Ag) hybrid nanostructures have been successfully fabricated using a series of solution process synthesis routes and an in-situ growth method. The prepared hybrid nanostructure is utilized for the fabrication of photovoltaic cells and the photocatalytic degradation of pollutants. The photovoltaic characteristics of a dye-sensitized solar cell (DSSC) device with plasmonic hybrid nanostructure (TiO2/rGO/Ag) photoanode achieved a highest short-circuit current density (JSC) of 16.05 mA/cm2, an open circuit voltage (VOC) of 0.74 V and a fill factor (FF) of 62.5%. The fabricated plasmonic DSSC device exhibited a maximum power conversion efficiency (PCE) of 7.27%, which is almost 1.7 times higher than the TiO2-based DSSC (4.10%). For the photocatalytic degradation of pollutants, the prepared TiO2/rGO/Ag photocatalyst exhibited superior photodegradation of methylene blue (MB) dye molecules at around 93% and the mineralization of total organic compounds (TOC) by 80% in aqueous solution after 160 min under continuous irradiation with natural sunlight. Moreover, the enhanced performance of the DSSC device and the MB dye degradation exhibited by the hybrid nanostructures are more associated with their high surface area. Therefore, the proposed plasmonic hybrid nanostructure system is a further development for photovoltaics and environmental remediation applications.

Experimentation of dyes extracted from the peels of red banana and aloe vera as sensitizers for TiO2-based dye-sensitized solar cells

As an attempt of utilizing the peels to extract dye sensitizers for dye-sensitized solar cell (DSSC), the peels of red banana (fruit) and aloe vera (leaf) were used in this study. As far as we know, for the first time the peels of red banana and aloe vera are being used as sensitizer for DSSC. Acetone and ethanol were used as solvent in extracting dyes from these peels. For the four extracted dyes, UV-visible and Fourier transform infra-red spectroscopic studies were carried out to know their absorption range and the functional groups present in it. DSSCs were made by using these extracted dyes as sensitizer and commercially available TiO2 as semiconductor oxide. XRD and SEM were recorded for the prepared TiO2 paste. To know about the performance of these solar cells, J-V characterization was taken and the efficiency of the DSSCs were determined. It was seen that among all the four DSSCs prepared, the DSSC made with the dye taken from aloe vera peel by using ethanol as solvent showed the higher efficiency of 0.679%.

Investigation of Aloe Vera Latex Used as Natural Dye in TiO2-Based Heterojunction and Liquid-Electrolyte Dye-Sensitized Solar Cells

Abstract The use of naturally extracted compounds as dye sensitizers is a very promising alternative for the manufacture of low-cost solar cells. These directly convert solar energy to electricity. In the present study, aloe latex solid (ALS), which is an orange-yellow solid compound extracted from aloe vera leaves, was deposited on a TiO2 thin film (TiO2/ALS) for the construction of two different solar cell configurations. The UHPLC-DAD-ESI-MS analysis, UV–Vis, and FTIR spectroscopic studies were performed for the prepared dye sensitizer. In fact, the performance of the TiO2/ALS composite was investigated in a heterojunction dye-sensitized solar cell (HJ-DSSC) and a liquid-electrolyte-based dye-sensitized solar cell (LE-DSSC) to identify the architecture with the highest efficiency of sunlight conversion. The solar cells’ photovoltaic performance in terms of short-circuit current, open-circuit voltage, fill factor, and energy conversion efficiency was tested with photocurrent density–voltage measurements. Interesting solar conversion efficiencies were obtained for both architectures with a maximum value of about 1.17% corresponding to the LE-DSSC configuration.

Theoretical studies, anticancer activity, and photovoltaic performance of newly synthesized carbazole-based dyes

We have synthesized a new class of carbazole-based cyanoacetanilides (5a-c) and carbazole based-thiazolidine derivatives (7a and 7b). These compounds were prepared from 9-hexylcarbazole by employing a multistep synthetic strategy and their structural elucidation was confirmed by the combination of standard spectroscopic methods such as FT-IR, 1H NMR, 13C NMR, MS, and UV–Vis spectral data. Through a theoretical approach using density functional theory (DFT) and molecular docking study, we have highlighted various parameters that influence the use of these new compounds as dye-sensitized solar cells (DSSCs) and anticancer agents. According to the DFT studies, all the structures (5a-c, 7a, and 7b) meet the prerequisite thermodynamic conditions, making them suitable to be employed as sensitizers in TiO2-based DSSCs. Additionally, the key photovoltaic parameters such as electron injection, regeneration, and recombination driving force (ΔGinj., ΔGreg. and ΔGrec.) of these compounds were calculated. Based on the computed results of the above factors, compound 7b is the most favorable candidate for sensitizing the DSSC performance. To further confirm these theoretical results, the experimental UV/Vis. spectra for compound 7b showed the broadest absorption range and the lowest energy gab (2.31 eV) with a maximum molar extinction coefficient of 2.29 × 104 M−1 cm−1, which reflects the better performance properties of dye 7b compared to other structures. Furthermore, the new compounds have been studied theoretically using human pancreatic cancer cells (PDB Code-3qkd) to investigate their anticancer activities. Interestingly, the better binding energy provided by the structure 7b in the silico molecular docking approach reveals its greater affinity for the receptor (binding energy: -9.7856 kcal mol−1 and RMSD: 1.66). Overall, the results suggest that compounds 5a-c, 7a, and 7b can be applied as potential sensitizers for dye-sensitized solar cells in addition to their performance as anticancer agents.

Dyes prepared from leaf extract of siriyanangai (Andrographis Paniculata) with the effect of TiO2 based DSSCs

Natural dyes are prepared through a dehydrated greeneries ofAndrographis Paniculataby the solvent acetone and alcohol. FTIR spectroscopic study and analysis have been undergone to efficiently assemble dyes and sensitizers in the fabricated TiO2-based Dye-Sensitized Solar Cells (DSSCs). An examined captivation characteristic of the dye sensitizer DSSC was recording UV–Vis spectrometry. Further, the breakthrough of the sensitizer for photovoltaic application, J (Am2) -V(V) characteristics study has been carried out for the fabricated DSSC observed extraction tint using acetone solvent and experimented DSSC has shown the photoconversion efficiency of 0.318% with 3.023, 0.3952, 1.4256, 0.1998 and 0.2395, which is analyzed with short circuit current density (Jsc - mA/cm2), Open circuit voltage (Voc - V), maximum current density (Jm - A⋅mm−2), maximum voltage density (Vm- V) and fill factor (FF- Pmax/ Isc × Voc) respectively.© 2022 Elsevier Ltd. All rights reserved.Selection and/or Peer-review under responsibility of International Conference on “Advancements in Nanoelectronics and Communication Technologies” (ICANCT-2022).

Improved luminescence performance of Yb3+-Er3+-Zn2+: Y2O3 phosphor and its application to solar cells

Upconversion materials (UC) can convert low-energy photons into visible light and, therefore, can be incorporated in solar cells to increase the absorption of visible light. This study synthesized UC nanophosphors Yb3+, Er3+: Y2O3 and Yb3+, Er3+, Zn2+: Y2O3 by a simple co-precipitation method for application in dye-sensitized solar cells (DSSCs). The impact of the enhancement in the concentration of Zn2+ on the photoluminescence (PL) and color point of the synthesized nanophosphors was also investigated. The synthesized nanophosphors emitted intense red and weaker green emissions upon excitation at 980 nm. The incorporation of Zn2+ to the Yb3+, Er3+: Y2O3 nanophosphors leads to color tunability in the red and yellow regions. Furthermore, the synthesized nanophosphors were incorporated into the DSSC photoanode to form a TiO2-UC-based DSSC for converting near-infrared (NIR) into visible light. We observed that the TiO2-UC-based DSSC showed an enhancement ratio in current density and power conversion efficiency of 17.4% and 16.6%, respectively, compared to the bare TiO2-based DSSC. These results reveal that UC-based Yb3+, Er3+, Zn2+: Y2O3 nanophosphors are useful in improving the efficiency of DSSCs and in color tunability applications.

MOF-derived Co2+-doped TiO2 nanoparticles as photoanodes for dye-sensitized solar cells

Facile synthesis and application of nano-sized semiconductor metal oxides for optoelectronic devices have always affected fabrication challenges since it involves multi-step synthesis processes. In this regard, semiconductor oxides derived directly from metal–organic frameworks (MOFs) routes have gained a great deal of scientific interest owing to their high specific surface area, regular and tunable pore structures. Exploring the application potential of these MOF-derived semiconductor oxides systems for clean energy conversion and storage devices is currently a hot topic of research. In this study, titanium-based MIL-125(Ti) MOFs were used as a precursor to synthesize cobalt-doped TiO2-based dye-sensitized solar cells (DSSCs) for the first time. The thermal decomposition of the MOF precursor under an air atmosphere at 400 °C resulted in mesoporous anatase-type TiO2 nanoparticles (NPs) of uniform morphology, large surface area with narrow pore distribution. The Co2+ doping in TiO2 leads to enhanced light absorption in the visible region. When used as photoanode in DSSCs, a good power conversion efficiency (PCE) of 6.86% with good photocurrent density (Jsc) of 13.96 mA cm−2 was obtained with the lowest recombination resistance and the longest electron lifetime, which is better than the performance of the pristine TiO2-based photoanode.

Intriguing CeO2–TiO2 hybrid nanostructured photoanode resulting up to 46% efficiency enhancement for dye-sensitized solar cells

The harvesting of electrical energy from sunrays with low cost, clean form and prosperity is an excellent progression. In this context, significant advancement has been made in the solar energy area in terms of cell's design to enhance efficiency. Light scattering may benefit solar cells in this aspect by extending the travelling distance of light within the photoelectrode film. In this work, dextran templating high-surface-area contained CeO2 nanoparticles (~22 nm) were employed to improve the power conversion efficiency (PCE) of a TiO2-based dye-sensitized solar cell (DSSCs). Various physicochemical techniques were investigated to characterize the synthesized CeO2 nanoparticles. Synthesized cubic CeO2 nanoparticles were further explored as an additional layer on the top of the synthesized anatase TiO2 nanocube based film to fabricate CeO2–TiO2 hybrid photoanode, encouraging light scattering in DSSCs. A comparative study was undertaken to understand the effect of the CeO2 layer on the synthesized and standard anatase TiO2. The overall power conversion efficiency obtained for hybrid photoanode-based DSSC is 8.92%, ~46% higher than that of TiO2 nanocubes-based photoanode, with a considerably improved open-circuit voltage of 0.83 V under 1 SUN AM 1.5 . In addition, the PCE enhancement is observed only ~8% using standard TiO2 based photoanode under the same condition. The photovoltaic performance highlights that dextran templating CeO2 nanoparticle exhibits a significant impact as the light scattering layer and heterojunction formation when incorporating on top of the anatase TiO2 nanocube resulting in a hybrid photoanode enhancing the PCE of DSSCs. This alternative approach could facilitate the performance of TiO2 based DSSCs towards improving efficiency.

Au-doped mesoporous SiO2 scattering layer enhances light harvesting in quasi Solid-State dye-sensitized solar cells

This study investigates the morphological effect of different Au-doped SiO2 scattering layers on the performance of dye-sensitized solar cells (DSSCs). Particularly, the SiO2 sources were varied to yield different geometries, i.e., tetraethyl orthosilicate (TEOS) templated SiO2, Sidoarjo mud (LuSi) extracted SiO2, and commercial silica glass sphere. The microstructure, as well as physical, electronic, and optical properties of different Au-doped SiO2 particles, were characterized using SEM-EDX, TEM, BET, XRD, and various spectroscopy techniques. The photoelectrochemical performance of quasi-solid state DSSCs was indicated by current density–voltage (J-V) response, external quantum efficiency spectra, and the impedance response. The results indicate that the performance of TiO2-based DSSCs is enhanced quite significantly due to the improved photocurrent generation and fill factor. The short circuit current density is found up to 370% higher (and hence, the conversion efficiency) than the reference cell upon incorporating Au-doped crystalline SiO2 extracted from LuSi (Voc = 0.89 V, Jsc = 1.28 mA‧cm−2, FF = 0.65, and η = 0.75%). This substantial photocurrent enhancement stems from the combined effect of efficient light scattering by submicron SiO2 particles, surface plasmon resonance, and reduced interfacial recombination by SiO2 insulation. In addition, the optimum size of SiO2 particles is deduced as the results indicate the size-scattering dependency which controls the gain and loss of photocurrent due to the type of scattering.

Tin(IV) oxide nanoparticulate films for aqueous dye-sensitized solar cells

Reported solar conversion efficiencies of aqueous dye-sensitized solar cells (DSSCs) trail those of traditional organic electrolyte-based systems but offer the potential for lower environmental impact and overall cost. Methods for improving the photochemical activity of aqueous DSSCs could also impact progress in related fields such as solar fuels and solar batteries. This work presents the first study solely focused on the use of SnO2-based photoanodes for use in aqueous DSSCs. Material design and interfacial engineering are critical to the effective use of SnO2 in this context, and it is found that mesoporous films comprised of both large 1–2 μm flower-like SnO2 particles and small 10–20 nm spherical SnO2 particles provide better performance than films composed of only one particle type. Insulating TiO2 coatings further improve the performance, and this work presents a facile liquid phase deposition strategy under ambient conditions using an aqueous TiF62- solution that proves more effective than the widely used method with TiCl4 for fabricating high-performing SnO2@TiO2 photoanode surfaces. The best aqueous DSSCs reported here using cis-bis(isothiocyanato)-bis(2,2′-bipyridyl-4,4′-dicarboxylato)ruthenium(II) dye and simple I3-/I- electrolyte achieve a power conversion efficiency of 0.7% which eclipses the first reported TiO2-based DSSC using otherwise identical dye and electrolyte composition.

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.