Performance Of Dye-sensitized Solar Cells Research Articles

Synergistic charge-transfer dynamics of novel D-D-A-π-A framework containing indoline-benzo[d][1,2,3]thiadiazole based push-pull sensitizers: from structural engineering to performance metrics in photovoltaic solar cells.

Dye-sensitized solar cells (DSSCs) present a convincing substitute for conventional silicon-based solar cells because of their possible lower manufacturing costs and versatile uses. Electron injection and dye regeneration processes are important in meeting the need for photosensitizers with improved efficiency and stability. Aimed at enhancing the performance and efficiency of DSSCs, this study focuses on the structural engineering to performance metrics of novel indoline-benzo[d][1,2,3]thiadiazole based push-pull sensitizers (LHZ1 to LHZ9) with D-D-A-π-A framework. The current study provides insights into the photovoltaic and optoelectronic properties of the investigated dyes, which are significantly influenced by the modification of auxiliary donors (D), internal acceptors with thiophene as a spacer, and cyanoacrylic acid (A) as the terminal acceptor. These modifications enhance rapid charge transfer among the dyes, highlighting the critical role of dye-semiconductor interactions. The suitability of developed sensitizers for DSSCs applications is confirmed by executing quantum methods like NBO, TDM, FMO, DOS, Eb, ΔGreg, ΔGinject, VRP, and ICT parameters qCT (e-), DCT ( ), H index ( ), ∆( ), t index ( ), and μCT (D). All of the investigated dyes have HOMO levels lower than the electrode I-/I3-'s redox potential (-4.8 eV) and LUMO values that are appropriately higher than the conduction band of TiO2 (-4.0 eV). The novel dyes showed a closing of the energy gap (2.38-1.84 eV). The LHZ7 and LHZ8 molecules with the lowest Eg (1.97 eV and 1.84 eV) demonstrated the highest absorption (up to 746 nm > 402 nm for LHZ), which was caused by the insertion effect of varied donors and internal acceptors. Almost all photosensitizers appeared with remarkable properties, i.e., red-shifted absorption maxima (746 nm), lowest Ex (1.66 eV), Eb (0.02 eV), and highest values of LHE (0.958). The TDM analysis revealed high charge density on HOMO of donor and LUMO of acceptors in designed dyes. DOS analysis revealed that the donor parts of the molecules delocalized the highest occupied molecular orbitals of dye particles. The electronic properties predicted by the NBO analysis showed that donor groups donate high and faster transfer of charge, and internal acceptor groups rapidly accept them. The electron injection (ΔGinject) and dye regeneration (ΔGreg) analysis of photosensitizers attached with TiO2 proved efficient charge transfer properties from the donor of newly designed dyes onto the conduction band of TiO2. This study, also supported by the thermodynamic stability of dyes with negative values of Gibbs free energy, revealed that the performance of the designed dyes is augmented by modifying the donor and internal acceptors of the reference photosensitizer for effective application in the experimental community. All of the dyes are suitable for DSSCs based on the calculated parameters. Still, the LHZ9 dye proved proficient in applying dye-sensitized solar cells due to its remarkable properties, i.e., lowest gap and red-shifted absorption maxima.

Characterization of Chlorophyll Based Dye-Sensitized Solar Cell using General-Purpose Photovoltaic Device Model

In dye-sensitized solar cells (DSSCs), light is absorbed by the sensitized dye. When light strikes the dye molecule, it absorbs photons and becomes excited to a higher energy state. This excited state allows the dye molecule to inject an electron into the conduction band of the semiconductor, generating an electric current. The selection of dye properties is very significant, as it can help to improve the performance of DSSCs. However, achieving an identical output current-voltage characteristic from the same batch of plants or fruits used as dyes is very difficult. Furthermore, improving the electrical performance, such as short-circuit current density and efficiency, of fabricated dye-sensitized solar cells is critical, as many experimental factors need to be considered. Therefore, to minimize the extra use of material resources due to the risk of unsuccessful fabrications and to obtain better performance ideally, conducting simulation-based studies is important to optimize the performance of DSSCs. The free software General-Purpose Photovoltaic Device Model (GPVDM) is a promising and interesting tool due to its free license and easy accessibility through a graphical interface for simulating optoelectronic devices, including OLEDs, OFETs, and various types of solar cells. This paper considers GPVDM, a 3-D photovoltaic device model, to simulate the proposed structure with different samples of chlorophyll dye for DSSC performance. The paper aims to characterize the high current density-voltage (J-V) of chlorophyll-based DSSCs and identify suitable photovoltaic simulation software for running simulations of chlorophyll-based DSSCs. Finally, the outcomes are compared with experimental data reported in various literature sources. The results show an enhanced short-circuit current density (Jsc) of 0.3556 mA cm-2 for Cordyline fruticose leaves (Chl E), which is the highest among the other dyes tested. The value of simulated short-circuit current density (Jsc) is slightly different from the experimented result Jsc reported in the published paper. In conclusion, GPVDM can be considered suitable for modeling DSSCs.

DFT/TD-DFT study of novel triphenylamine-based dyes with azo moieties and π-spacer variations for enhanced dye-sensitized solar cell performance

This study involves a computational analysis of new D-π-A dyes obtained from triphenylamine (TPA), which contain various azo-dye components. The structural, molecular, electrical, and optical properties of these dyes were computed using Density Functional Theory (DFT) and Time-Dependent DFT, utilizing the B3LYP/6–31 G model. Our research specifically aimed to investigate the effects of incorporating different azo dye constituents in the para position of two phenyl groups of TPA. The results indicate that these alterations lead to notably broadened and red-shifted absorption spectra, as well as improved optoelectronic properties that are subject to additional tuning through the manipulation of the π-spacer. The excitation energies and HOMO-LUMO energy levels that have been estimated indicate the presence of effective electron injection and dye regeneration mechanisms. The results concerning the nonlinear optical (NLO) properties suggest that these dyes are likely to demonstrate superior performance in NLO applications. The factors encompassed in this study consist of light-harvesting efficiency (LHE), open-circuit photovoltage (VOC), electron injection driving force (ΔGinj), dye regeneration driving force (ΔGreg), excited state lifetime (τ) and reorganization energy (λtotal), which has a strong correlation with the electrical current density in a short-circuit (JSC) and DSSC's overall effectiveness. This scientific attempt contributes to the systematic advancement of efficient dyes, demonstrating the possibility for enhanced efficiency in DSSCs. Further validation of computational forecasts and advancement of renewable energy technology necessitate future experimental synthesis and testing.

Design and Performance Analysis Of Complete Solid-State Dye Sensitised Solar Cell Using Eosin-Y Xanthene Dye: a SCAPS -1D Simulation Study

This paper reports the theoretical simulation study of the performance of a complete solid-state dye-sensitised solar cell with Eosin-Y as the photosensitizer and PEDOT: PSS as the hole transport layer. SCAPS-1D software is used for the simulation under quasi-ideal conditions and got an optimised efficiency of 4.19%, which matches much with the reported experimental values in the literature. These finding indicates the potential of Eosin-Y as a cost-effective photosensitiser capable of performing even under dim light conditions.

Sappanwood-derived green luminescent carbon dots for enhancing performance of dye-sensitized solar cell

Sappanwood-derived green luminescent carbon dots for enhancing performance of dye-sensitized solar cell

Investigate the utilization of novel natural photosensitizers for the performance of dye-sensitized solar cells (DSSCs)

Dye-sensitized solar cells (DSSCs) offer a promising route for sustainable energy conversion, with natural photosensitizers emerging as attractive alternatives to conventional synthetic dyes due to their abundant resources, cost-effectiveness, and eco-friendly materials. However, the efficiency of DSSC utilizing natural photosensitizer remains low. In this study, we investigate the utilization of novel natural photosensitizers extracted from gambier leaves, gambier branches, cinnamon, and petiole of tectona leaves, which contain flavonoids/tannins, chlorophyll, and anthocyanins, aiming to achieve high-performance DSSCs. Five different solvents—ethanol, isopropanol, distilled water, methanol, and Zamzam water—are explored to optimize the extraction process of the natural dyes. The doctor blade technique is employed to coat TiO2 nanomaterials onto ITO glass substrates. UV–Vis spectrophotometry and FTIR spectroscopy are used to characterize the optical properties and structural composition of the dyes, revealing that flavonoid/tannin groups are the primary compounds responsible for light harvesting. The DSSC performance is evaluated under a 30 W lamp, adjusted to light intensity of 10 mW/cm2. As a result, the DSSCs using gambier leaf extract as photosensitizer demonstrate the highest recorded efficiency of 4.71 %, with a Jsc of 2.95 mAcm−2 and a Voc of 0.64 V. These findings contribute to advancing DSSC technology by leveraging the potential of natural photosensitizers for sustainable energy conversion applications.

Combine Improvement for Dye-Sensitized Solar Cells

Dye Sensitized-Solar Cells (DSSC) represent a third-generation solar cell technology based on photoelectrochemical principles. This study explores the use of Clitoria ternatea (butterfly pea) extract as an organic dye for DSSCs, focusing on its ability to absorb sunlight effectively. Excitation of electrons triggered by light in photocatalysis is strongly influenced by the position of the band gap. To be effective as a photocatalyst, the material must have a conduction band with a high positive potential compared to the electron accepting potential. Doping metal oxides such as CuO, MgO, Fe2O3, and ZnO into TiO2 can change the band edge properties or surface states which can increase light absorption. This research presents the synthesis of TiO2 nanoparticles as photoanodes doped using metal oxides to evaluate characteristic that can influence DSSC performance. TiO2 nanoparticles doped with metal oxide were synthesized using the solvothermal method and characterized by XRD, SEM-EDX, FTIR, and UV-Vis. Comprehensive analysis of samples doped with metal oxides significantly affects the crystal structure, morphology, elemental composition, and optical properties of the material. The results showed that Cu-doped TiO2 samples allowed for the most significant performance improvement in DSSC, followed by Fe-doped TiO2, Mg-doped TiO2, and Zn-doped TiO2, with pure TiO2 having the lowest performance potential. These results provide important insights into material optimization to improve DSSC efficiency.

Optimizing dye-sensitized solar cell efficiency through TiO2/CuS doping: effects of internal parameter variations

Dye-sensitized solar cells (DSSC) have attracted significant research interest due to their semi-transparency, ease of fabrication, cost-effectiveness, and environmental friendliness. This research focuses on enhancing dye-sensitized solar cells efficiency by doping titanium dioxide with copper sulfide and varying internal parameters such as concentration, thickness, and temperature. The primary issue addressed is the low electron mobility of titanium dioxide, which limits its performance as a photoanode. Using simulation methods, this study analyzed dye-sensitized solar cells performance under different doping conditions. The results showed that the highest efficiency of 8.18 % was achieved at a TiO2/CuS concentration of 0.3 %. The optimal photoanode thickness was approximately 3 μm, yielding an efficiency of 8.33 %. Temperature variations at room temperature (275 K, 300 K, and 325 K) resulted in efficiency values of 13.94 %, 15.06 %, and 16.18 %, respectively. These findings indicate that targeted doping and precise control of internal parameters can significantly enhance the performance of titanium dioxide-based dye-sensitized solar cells. The improved efficiency is attributed to enhanced electron mobility and better structural and morphological characteristics of the doped titanium dioxide photoanode. This research provides valuable insights into developing more efficient and sustainable dye-sensitized solar cells. The practical implications of these results are significant for advancing dye-sensitized solar cells as a viable alternative to conventional solar cells, contributing to the global effort to address the energy crisis by providing a cost-effective and environmentally friendly energy source.

Effect of electron-donating and -withdrawing substitutions in naphthoquinone sensitizers: The structure engineering of dyes for DSSCs in Quantum Chemical Study

Dye-sensitized solar cells (DSSCs) are cost-effective photovoltaic devices that convert solar energy into electricity using a dye sensitizer, TiO2 photoanode, electrolyte, and counter electrode. This study investigates the impact of substituents on the performance of naphthoquinone-based dye sensitizers in DSSCs. We analyzed various naphthoquinone derivatives’ electronic structures and light absorption properties using DFT and TD-DFT. Our results demonstrate that electron-donating groups enhance DSSC performance by improving light absorption and electron injection. Specifically, naphthoquinone derivatives with methoxy (Dye-2) and methyl (Dye-3) groups showed superior properties. TD-DFT analysis revealed high molar extinction coefficients over a broad spectrum, making these dyes efficient at capturing sunlight. Additionally, these dyes effectively interact with TiO2, which is crucial for photostability and photovoltaic performance. In conclusion, naphthoquinone derivatives with electron-donating groups significantly improve DSSC performance, with Dye-2 and Dye-3 being strong candidates for high-performance applications.

Enhanced dye-sensitized solar cell performance using Ag nanoparticle-decorated TiO2 nanowire photoanode using the GLAD technique

Enhanced dye-sensitized solar cell performance using Ag nanoparticle-decorated TiO2 nanowire photoanode using the GLAD technique

Novel D–π–A dye as a co-sensitizer of indoline and benzothiadiazole dyes to enhance photovoltaic performance of dye-sensitized solar cells

A novel D–π–A type of dye (BIM33) comprising diphenylamine as electron donor, diphenylacridine as a π-bridge and cyanoacrylic acid as an anchoring unit has been synthesized and used as sensitizer and co-sensitizer in dye-sensitized solar cells (DSSCs). The DSSC based on BIM33 achieved a power conversion efficiency (PCE) of 3.19 % under one sun (AM 1.5G). To improve the photovoltaic performance of the DSSCs, this orange dye was also co-sensitized with red benzothiadiazole (C1) and purple indoline (D205) organic dyes. The DSSCs based on co-sensitizers BIM33/D205 and BIM33/C1 showed superior PCEs of 6.57 % (JSC = 13.69 mA cm−2, VOC = 0.766 V, and FF = 0.63) and 6.82 % (JSC = 14.47 mA cm−2, VOC = 0.722 V, and FF = 0.65), respectively, exhibiting significant improvements of 28 % and 36 % compared to the DSSCs based on D205 and C1, respectively. The high photovoltaic performance of the co-sensitized DSSCs may be explained by the broader visible light absorption and a denser packing of the dyes on the TiO2 surface.

Multiphasic titania photoanode: A facile phase assisted approach to enhance the photoelectrochemical and photovoltaic performance

A facile low-temperature method has been proposed and utilized to synthesize pristine and multiphasic titania. Increasing reactant acid content led to the phase transition of titania from pristine anatase to triphasic anatase-rutile-brookite mixed phase; then to biphasic anatase-rutile mixed phase and ultimately pristine rutile. Morphological differences between the samples led to different dye loading on the Dye Sensitized Solar Cell (DSSC) photoanodes, with anatase showing highest loading. However, the Electrochemical Impedance Spectroscopic (EIS) analyses revealed that the triphasic titania photoanode showed superior charge transport ability as evidenced by the lowest charge transfer resistance and highest carrier lifetime. This led to the triphasic DSSC showing a photoconversion efficiency of 4.23 % which is 45 % greater than the reference DP25 DSSC and 72 % better than that of the anatase DSSC despite having a 24 % lower dye loading. These factors suggest that the charge transport properties precede the dye loading capability of the photoanode in determining the DSSC performance. The intimate ternary interfacial junction between the anatase, rutile and brookite phases may be responsible for the enhanced charge transport properties of the triphasic titania. Thus, it is essential to ensure superior photoanode charge transport characteristics to enhance the DSSC performance.

Optimized Nb‐Doped TiO2/rGO Nanocomposites for Assessment of Photovoltaic Performance With Metal‐Free Dye and Polymer Gel Electrolyte

AbstractThis research presents the development of niobium (Nb)‐doped titania (TiO2)/reduced graphene oxide (rGO) nanocomposites (NTR NCs) for dye‐sensitized solar cells (DSSCs). The novelty lies in two aspects: introducing Nb (V) ions into TiO2/rGO nanocomposites via an in‐situ sol‐gel method with doping concentrations from 1.0 to 3.0 mol %, and fabricating photoanodes using the doctor blade technique, sensitized with a Co2+/Co3+‐based PEO‐PEG polymer gel electrolyte‐assisted D‐π‐A carbazole metal‐free (SK3) dye. Detailed investigations into the optoelectrical, structural, and morphological properties were conducted using various spectral and analytical tools. Notably, DSSCs based on Nb‐doped TiO2/rGO nanocomposites with 2.0 mol % Nb (NTR‐2) achieved a remarkable solar efficiency (η) of 5.48 % under AM 1.5 solar simulation, significantly outperforming devices based on bare TiO2 nanoparticles and undoped TiO2/rGO NCs by factors of 4.15 and 2.97, respectively. The substantial enhancement in photovoltaic performance is attributed to superior charge transfer properties and higher carrier density, as revealed by electrochemical impedance spectroscopy (EIS) and Mott‐Schottky (M–S) analysis. Nb‐doping results in an energetic surface nature, improved optical absorption, and reduced charge transfer resistance, collectively boosting the overall efficiency of DSSCs. This work underscores the potential of Nb‐doped TiO2/rGO NCs as effective photoanode materials in enhancing DSSC performance.

A Bi2Te3 topological insulator/carbon nanotubes hybrid composites as a new counter electrode material for DSSC and NIR photodetector application

Two-dimensional layered bismuth telluride (Bi2Te3), a prominent topological insulator, has garnered global scientific attention for its unique properties and potential applications in optoelectronics and electrochemical devices. Notably, there is a growing emphasis on improving photon-to-electron conversion efficiency in dye-sensitized solar cells (DSSCs), prompting the exploration of alternatives to noble metal catalysts like platinum (Pt). This study presents the synthesis of Bi2Te3 and its hybrid nanostructure with single-wall carbon nanotubes (SWCNT) via a straightforward hydrothermal process. The research unveils a novel application for the Bi2Te3-SWCNT hybrid structure, serving as a counter electrode in platinum-free DSSCs, facilitating the conversion of triiodide (I3−) to iodide (I−) and functioning as an active electrode material in a photodetector (n-Bi2Te3-SWCNT/p-Si). The resulting DSSC employing the Bi2Te3-SWCNT hybrid counter electrode achieves a power conversion efficiency (PCE) of 4.2 %, a photocurrent density of 10.5 mA/cm2, a fill factor (FF) of 62 %, and superior charge transfer kinetics compared to pristine Bi2Te3 based counter electrode (PCE 2.1 %, FF 34 %). Additionally, a spin coating technique enhances the performance of the n-Bi2Te3-SWCNT/p-Si photodetector, yielding a responsivity of 2.2 AW−1, detectivity of 1.2 × 10−3 and enhanced external quantum efficiency. These findings demonstrate that the newly developed Bi2Te3-SWCNT heterostructure enhances interfacial charge transport, electrocatalytic performance in DSSCs, and overall photodetector performance.

Effects of ALD Deposition Cycles of Al2O3 on the Morphology and Performance of FTO-Based Dye-Sensitized Solar Cells

In dye-sensitized solar cells (DSSCs), materials classified as Transparent Conducting Oxides (TCOs) have the capacity to conduct electricity and transmit light at the same time. Their exceptional blend of optical transparency and electrical conductivity makes them popular choices for transparent electrodes in DSSCs. Fluorine Tin Oxide (FTO) was utilized in this experiment. The optical and electrical characteristics of TCOs may be negatively impacted by their frequent exposure to hostile environments and potential for deterioration. TCOs are coated with passivating layers to increase their performance, stability, and defense against environmental elements including oxygen, moisture, and chemical pollutants. Because of its superior dielectric qualities, strong chemical stability, and suitability with TCO materials, aluminum oxide (Al2O3) was utilized as a passivating layer for the FTO. In this research work, Al2O3 was deposited via atomic layer deposition (ALD) to form thin mesoporous layers as a passivator in the photoanode (working electrode). The work focuses on finding an appropriate thickness of Al2O3 for optimum performance of the dye-sensitized solar cells. The solar simulation and sheet resistance analysis clearly showed 200 cycles of Al2O3 to exhibit an efficiency of 4.31%, which was the most efficient performance. The surface morphology and topography of all samples were discussed and analyzed.

Coating of CoS on hybrid anode electrode with enhance performance in hybrid dye-sensitized solar cells

Improvement of the power generation performance of dye-sensitized solar cells (DSSCs) remains a key task, as charge transfer and charge separation are efficiently achieved at the photoanode and between the polysulfide electrolyte interface and the counter-electrode. We synthesized the metal sulfides from dithiocarbamate complexes and used them to fabricate a new modified cell by passivating the photoanode electrode with CoS nanoparticles and SnS as photosensitizer in a two-step deposition approach. They were used as FTO-TiO2/CoS/SnS/HI-30/FTO-Pt, known as C-S-1, C-S-2 and C-S-3. SEM images show that the C-S-1 and C-S-2 are uniform, without cracks and have a dense surface morphology covering the surface area. Thus, confirming the successively passivation by CoS and sensitization of SnS, forming FTO-TiO2/CoS/SnS heterostructure. The η of 8.79% and 9.43% are much higher than that of C-S-2, with 0.23% affirm the roles of the Co, Sn and S ratio on both devices. The EIS Nyquist plot for the C-S-2 device shows a semicircle radius smaller than the C-S-1 and C-S-3, which indicates more efficient inhibition of electron/hole pairs and faster transportation of photogenerated charge carriers. The enhanced performance of both devices shows that the passivation of the electrodes ensures that maximum absorption is achieved through a higher absorption coefficient of SnS. Also, both devices reach a steady state within about 200–300 s and remain at the steady state current for a long duration for C-S-1 and C-S-3. The enhanced performance of both devices shows that the passivation of the electrodes ensures that maximum absorption is achieved through a higher absorption co-efficient of SnS.

Cyanoacetamide co-sensitizers DY-1 and DY-2: Unveiling a promising path to highly efficient photovoltaic devices

This paper presents a novel approach for enhancing the efficiency of dye-sensitized solar cells (DSSCs) through the co-sensitization of cyanoacetamide-based dyes DY-1 and DY-2 with N3 dye. The synthesis and characterization of DY-1 and DY-2 co-sensitizers are described and their potential applications in photovoltaic devices are investigated. The absorption properties of DY-1 and DY-2 were analyzed, revealing their efficient light absorption in the visible range. The co-sensitization of DY-1-2 with N3 dye demonstrated a significant enhancement in photovoltaic efficiency, ranging from 7.40 % to 7.92 %. The reasons for this efficiency enhancement were thoroughly analyzed and attributed to several factors. First, the combination of DY-1-2 with the N3 dye led to a broader light absorption spectrum, enabling more efficient utilization of incident photons. Additionally, co-sensitization facilitates efficient charge separation and injection processes, contributing to improved photocurrent. The acid-base co-sensitization approach further enhances the overall efficiency by maximizing the charge transfer and coverage on the semiconductor surface. This study sheds light on the development of novel sensitizers to enhance the performance of DSSCs, and the findings contribute to the advancement of photovoltaic devices.

Photophysical Properties and Photovoltaic Performance of Sensitizers with a Bipyrimidine Acceptor

Molecular engineering is a crucial strategy for improving the photovoltaic performance of dye-sensitized solar cells (DSSCs). Despite the common use of the donor–π bridge–acceptor architecture in designing sensitizers, the underlying structure–performance relationship remains not fully understood. In this study, we synthesized and characterized three sensitizers: MOTP-Pyc, MOS2P-Pyc, and MOTS2P-Pyc, all featuring a bipyrimidine acceptor. Absorption spectra, cyclic voltammetry, and transient photoluminescence spectra reveal a photo-induced electron transfer (PET) process in the excited sensitizers. Electron spin resonance spectroscopy confirmed the presence of charge-separated states. The varying donor and π-bridge structures among the three sensitizers led to differences in their conjugation effect, influencing light absorption abilities and PET processes and ultimately impacting the photovoltaic performance. Among the synthesized sensitizers, MOTP-Pyc demonstrated a DSSC efficiency of 3.04%. Introducing an additional thienothiophene block into the π-bridge improved the DSSC efficiency to 4.47% for MOTS2P-Pyc. Conversely, replacing the phenyl group with a thienothiophene block reduced DSSC efficiency to 2.14% for MOS2P-Pyc. Given the proton-accepting ability of the bipyrimidine module, we treated the dye-sensitized TiO2 photoanodes with hydroiodic acid (HI), significantly broadening the light absorption range. This treatment greatly enhanced the short-circuit current density of DSSCs owing to the enhanced electron-withdrawing ability of the acceptor. Consequently, the HI-treated MOTS2P-Pyc-based DSSCs achieved the highest power conversion efficiency of 7.12%, comparable to that of the N719 dye at 7.09%. This work reveals the positive role of bipyrimidine in the design of organic sensitizers for DSSC applications.

Carbon dots-Zno/TiO2 ternary nanocomposite as a proficient material to enhance the performance of natural DSSC

A novel sustainable approach for enhancing the efficiency of dye-sensitized solar cells (DSSCs) involves the utilization of a combination of ZnO and carbon dots (CDs) derived from Citrus medica fruit extract, along with microwave-synthesized TiO2 nanoparticles for the preparation of the photoanode. Natural dyes such as Hibiscus rosa-sinensis and Allium Cepa peel are employed as sensitizers to reduce production costs. This co-activation method has demonstrated a significant improvement in the output parameters of the devices. Notably, the photoanode co-activated with ZnO-CD composite (ZnO-CD/TiO2) exhibits the most favorable output parameters when combined with Hibiscus rosa-sinensis dye (open circuit voltage (Voc) = 0.80 V, short circuit current density (Jsc) = 6.62 mA/cm2, fill factor (FF) = 64.20 %, photo conversion efficiency (PCE) = 3.40 %) and Allium Cepa peel dye (Voc = 0.81 V, Jsc = 6.79 mA/cm2, FF = 65.70 %, PCE = 3.61 %). When paired with Allium Cepa dye, the CD modified photoanode (CD/TiO2) offers Voc = 0.73 V, Jsc = 6.64 mA/cm2, FF = 61.27 % and PCE = 2.97 %. Similarly, when combined with Hibiscus rosa-sinensis dye, the output parameters of the CD/TiO2 photoanode are Voc = 0.72 V, Jsc = 6.54 mA/cm2, FF = 64.4 % and PCE = 3.03 %. In comparison to all tested devices, the unmodified photoanode (TiO2) displayed the lowest performance, with parameters such as Voc = 0.59 V, Jsc = 6.45 mA/cm2, FF = 52.5 %, PCE = 2.10 % using Allium Cepa peel dye, and Voc = 0.66 V, Jsc = 6 mA/cm2, FF = 51.60 %, PCE = 2.04 % using Hibiscus rosa-sinensis dye. Furthermore, the co-activation process has been shown to enhance the stability of the devices. While the unmodified photoanodes ceased to operate after eight days, the ZnO-CD composite co-activated photoanodes retained their initial efficiencies up to 61.50 % and 68.53 % with the Allium Cepa peel dye and Hibiscus rosa-sinensis dye, respectively. Therefore, this study underscores the potential of the synthesized composite material in enhancing the performance of natural DSSCs.

Enhanced visible light harvesting in dye-sensitized solar cells through incorporation of solution-processable silver plasmons and anthracite-derived graphene quantum dots

The major setback for the enhanced performance of DSSC is the narrow absorption window and the interfacial exciton recombination. Therefore, in this work, the photovoltaic performance of dye-sensitized solar cells has been improved by the synergistic effect of anthracite-derived graphene quantum dots and silver plasmons. GQD and Ag coupled photoanodes were fabricated by a facile solution processable process under room temperature. The as-fabricated DSSC TiO2/Ag/GQD (TAG) exhibited an enhanced power conversion efficiency of 10.5 % with a current density of 22.40 mAcm−2 measured under solar irradiation of 100 mWcm−2 with AM 1.5G. An enhancement surpassing 30.5 % was obtained for the champion cell when compared to the pristine TiO2 based DSSC. Furthermore, this study emphasizes developing a cutting-edge approach for the high-quality use of fossil fuel-derived graphene quantum dots in energy conversion systems, thereby encouraging the green conversion of fossil fuels and broadening the potential of anthracite coal's utilization in energy conversion applications.