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For photoelectrochemical water splitting, tungsten trioxide (WO3) films with a monoclinic structure were synthesized on fluorine-doped tin oxide coated glass substrates with a vacuum evaporation method. To control the WO3 film thickness from 0.42 to 5.6 μm, the crystal orientation was intergraded from the (200) crystal plane to the (002) one. In x-ray diffraction measurements, the intensity ratio of the (002) crystal plane to the (200) one was defined as rp. In the WO3 photoelectrode with higher (002)-preferred orientation, the photocurrent continued to flow even when the incident light against the photoelectrode was completely blocked after the irradiation for 60 s. This suggests that hydrogen continues to be produced owing to the electrons charged by the formation of a hydrogen tungsten bronze (HxWO3) phase. After 72 s, the photocurrent density of the WO3 photoelectrode with rp = 42 became one-tenth of the value before the incident light was blocked. This charge release time was remarkably long compared to those of the WO3 photoelectrodes with (200)-preferred orientation and non-orientation. Therefore, it was considered that the hydrogen ion diffusion through the defects in the WO3 crystals tends to occur in the [002] crystal direction. However, the improvement in the (002)-preferred orientation can facilitate the structural change from the WO3 phase to the HxWO3 one for the entire film. [ABSTRACT FROM AUTHOR]

The main challenge for solar cell devices is harvesting photons beyond the visible by reaching the red-edge (650–780 nm). Dye-sensitized solar cell (DSSC) devices combine the optical absorption and the charge separation processes by the association of a sensitizer as a light-absorbing material (dye molecules, whose absorption can be tuned and designed) with a wide band gap nanostructured semiconductor. Conformational and environmental effects (i.e., solvent, pH) can drastically influence the photophysical properties of molecular dyes. This study proposes a combined experimental and computational approach for the comprehensive investigation of the electronic and vibrational properties of a unique class of organic dye compounds belonging to the family of red-absorbing dyes, known as squaraines. Our focus lies on elucidating the intricate interplay between the molecular structure, vibrational dynamics, and optical properties of squaraines using state-of-the-art density functional theory calculations and spectroscopic techniques. Through systematic vibrational and optical analyses, we show that (i) the main absorption peak in the visible range is influenced by the conformational and protonation equilibria, (ii) the solvent polarity tunes the position of the UV–vis absorption, and (iii) the vibrational spectroscopy techniques (infrared and Raman) can be used as informative tools to distinguish between different conformations and protonation states. This comprehensive understanding offers valuable insights into the design and optimization of squaraine-based DSSCs for enhanced solar energy conversion efficiency. [ABSTRACT FROM AUTHOR]

To achieve dye-sensitized solar cells (DSSCs) with high transparency, multi-color capability, and long-term durability for future applications across various fields, this study selected phenylthiophene with UV-absorbing properties as the dye electron donor, cyanoacetic acid as the electron acceptor, and a colorless biphenyl dye (6OBA) as the co-sensitizer. The effects of different alkyl chain lengths, densities, branching positions, and co-sensitization on the photovoltaic (PV) performance of the devices are investigated. In addition, the effect of dye molecules adsorbed on TiO2 films of different thicknesses on the optical transmittance of the devices was also analyzed. The results show that the developed dyes exhibit UV-selective absorption properties. The power conversion efficiencies (PCEs) of the semi-transparent DSSCs ranged from 0.51% to 0.89% under one sun illumination (100 mW cm−2) and from 3.78% to 5.94% under UVA LED illumination (365 nm, 150 μW cm−2). The corresponding visible light transmittance varied between 33.47% and 63.71%. At the same time, the DSSCs demonstrated long-term PCE stability after soaking for 1000 hours of full light irradiation. [ABSTRACT FROM AUTHOR]

TiO2 is one of the most studied semiconductor materials for the photoelectrochemical water splitting to hydrogen production, but it only responds to ultraviolet light. The introduction of organic compound is one of the common means to expand the visible light response of TiO2. In this work, rutile TiO2 nanowire arrays (NWs) were grown on conductive glass by a modified solvothermal method using oleic acid as the key additive. The obtained TiO2 NWs are characterized using x-ray diffraction, x-ray photoelectron spectroscopy, infrared spectroscopy and electrochemical characterization. The results show that the carboxyl groups arising from oleic acid are chemically bonded with the TiO2 NWs in the form of chelating bidentate, which increases the visible light absorption range and active sites of TiO2, and reduces the transfer resistance between the photoelectrode and the electrolyte. The photocurrent density is doubled to 0.17 mA cm−2 at 1.23 V vs. RHE. This work provides a novel idea for the design of metal oxide semiconductor photoanodes by adsorbing organic compounds. [ABSTRACT FROM AUTHOR]

The quest to enhance solar cell performance has long been driven by increasing energy demands and environmental concerns, and much progress has been achieved by way of interface modifications. As the demand for sustainable energy increases and environmental awareness pushes us toward cleaner solutions, the spotlight turns to stable and eco-friendly metal oxide semiconductors for photovoltaic applications. This research highlights the exceptional electronic and optical characteristics of ZrO2@GO nanoparticles, focusing on molecular electrostatic potential (MEP), nonlinear optical properties (NLO), and electron localization function (ELF). Our findings highlight that ZrO2@GO exhibits superior electronic characteristics compared to bare graphene oxide. This superiority motivates us for the co-sensitization of ZrO2@GO with squaraine dyes, which are well known for their strong light harvesting in dye-sensitized solar cells (DSSC). Using density functional theory (DFT) with Gaussian 09, we examine critical parameters that include the highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO), energy gap, maximum wavelength (λmax), electron injection efficiency (ΔGinject), open-circuit voltage (Voc), reorganization energy (λreorg), among others. Our research highlights the high optical transmittance of ZrO2@GO, positioning it as a promising material for advanced optical, electrical, and light-harvesting devices with improved performance and efficiency. [ABSTRACT FROM AUTHOR]

This scientific paper presents a novel approach to explore and predict the potential of imidazole-based organic dyes for use in Dye-Sensitized Solar Cells (DSSCs) using a machine learning web application. The design of efficient and cost-effective organic dyes is critical to enhance the performance of DSSCs. Traditional experimental methods are time-consuming and resource-intensive, making it challenging to screen a large number of potential dyes. In this study, we propose a machine learning-based approach to accelerate the discovery process by predicting the photovoltaic performance of imidazole-based organic dyes. Machin learning predictions provide valuable insights into the expected PCE% and behaviors of the molecules toward DSSCs. Based on the RDKit library, several fingerprints such as Molecular ACCess System, Avalon, Daylight, Pharmacophore and Morgan with different radius (r2, r3, r4), were studied. In addition, more than 20 ML algorithms using different cross validation (3, 5, 7, 10) were also evaluated. Among of these, Deep Neural Network models of MLPRegressor algorithm based on the daylight fingerprint shows a significant coefficient of determination combined with the lowest errors. Utilize the trained ML models to screen of 50 million SMILE structure for identify promising imidazole and nitrogen-containing derivative as a doner group. By replacing the donor groups in the well-known MK2 dye structure with the top imidazole derivatives proposed by machine learning, significant improvements in PCE were observed, increasing from 7.70% to as high as 11.49%, representing nearly a 50% enhancement over the control. DFT calculations confirm the ML predictions and clarify the significantly higher oscillator strength and charge transfer properties of MK2-DM1, compared to MK2. This result provides a promising pathway for developing new dye materials that can push the efficiency limits of DSSCs, leading to more efficient solar energy conversion technologies in the future. In addition, a developed web application offers a user-friendly interface for researchers to input their molecular structures and obtain PCE% predictions toward DSSCs. This information can guide researchers in designing a new imidazole dye with high photovoltaic performance to validate and refine the predictions without time consuming. [ABSTRACT FROM AUTHOR]

In recent years, there is a growing interest in the development of sustainable sensitizers for the dye-sensitized solar cell (DSSC) applications. The earth-abundant transition metal complexes offer a potential alternative option to the problematic ruthenium-based dyes, owing to their interesting photophysical properties and eco-friendly nature. This review accounts in detail the development of sustainable late transition metal-sensitizers in the DSSCs. Attempts are made to comprehensively describe the various strategies involved in the molecular design of the potential dye-molecules as well as the methodologies involved in the cell-fabrication. We hope that this review will serve as a promptuary to the researchers and inspire further developments in this field. [ABSTRACT FROM AUTHOR]

Herein, we reported the synthesis of MnO2/ZIF-8 composite by employing two-step synthetic procedure. The synthesized samples have been characterized by utilizing various sophisticated physicochemical technique such as X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and energy-dispersive X-ray (EDX) spectroscopy. The synthesized MnO2/ZIF-8 has been used as counter electrode (CE) for the fabrication of dye-sensitized solar cells (DSSCs). The effect of annealing temperature was studied, and the highest efficiency of 7.2% with a decent open-circuit voltage (Voc) of 0.77 V was achieved at 200 °C. The obtained efficiency of 7.2% is reasonable in comparison to the platinum (Pt)-based DSSCs (7.4%). This work proposed the construction of Pt-free CE for the development of cost-effective DSSCs with reasonable performance in terms of efficiency. [ABSTRACT FROM AUTHOR]

Dye-sensitized solar cells (DSSCs) exhibit considerable potential as a promising technology, particularly when addressing the challenge of replacing the costly Platinum (Pt) counter electrode (CE) with economically viable and chemically stable CE materials. This study examines the use of two-dimensional hexagonal-shaped nickel oxide nanosheets substituted with varying mol% of lithium (1, 3, and 5 %) (Li (1–5%)-NiO NSs) as the counter electrodes (CEs) for DSSCs. The facile hydrothermal method was employed for the preparation of NiO and Li (1–5 mol%)-NiO samples. The BET analysis of NiO and Li (1–5%)-NiO indicates that higher concentrations of Li1+ ions in Ni2+ ions sites lead to an increase in the overall surface area of NiO. This leads to an elevated number of exposed electrocatalytic active sites which resulted in enhancing the rate of reduction of I 3 − ions. The cyclic voltammetry (CV) result of 5 mol% of Li substituted NiO (5-LNO) shows outstanding electrocatalytic activity towards the redox reaction of I 3 − / I − redox mediator among the as-prepared CEs. The DSSCs assembled with 5-LNO CE show an excellent power conversion efficiency (η) of 5.84 % with short-circuit current (J s c) of 18.76 mAcm−2, and open-circuit voltage (V o c) of 0.80 V which is higher than Pt-based CE (η of 4.05 % with J s c of 10.16 mAcm−2, and V o c of 0.69 V). The DSSCs fabricated with 5-LNO CE exhibit excellent photovoltaic performance because of their high active surface area and enhanced electrical conductivity. The 5-LNO CE has low cost, significant electrocatalytic activity, less toxicity, and superior device efficiency than NiO, other Li (1–3%)-NiO, and Pt CEs, making it a suitable candidate for Pt-free DSSCs application. [ABSTRACT FROM AUTHOR]

The performance of dye-sensitized solar cells (DSSC) primarily depends upon many factors, such as the thickness of the semiconductor layer at the working electrode, dye/sensitizer concentration, and electrolyte. A methodical study is required in one place to deliberate the impact of all these factors on DSSC performance for better understanding and further advancement of the technology. This work emphasizes optimizing the absorption layer, specifically investigating the relationship between the thickness of the TiO2 layer and the concentration of N719 dye. The objective is to elucidate the interconnected effects of these parameters on the overall performance of the device. Additionally, the optimization of electrolyte composition was done with varying concentrations of additives, such as iodine, 4-tert-butyl-pyridine (TBP), guanidinium thiocyanate (GuNCS), and 1-butyl-3-methylimidazolium iodide (BMII) of electrolyte. Initially, the devices with varying TiO2 absorption layers were fabricated. The efficiency, fill factor (FF), open-circuit voltage (VOC), and short-circuit current (ISC) of devices were studied. The drop in open-circuit voltage (VOC) was noticed with the increase in thickness of the TiO2 layer. The highest efficiency was observed at 7.17% with the device fabricated using 6 absorption layer (17.46 μm) of TiO2, 0.7 mM concentration of N719 dye, and 0.03-M iodine, 0.1-M GuNCS, 0.5-M TBP, and 0.6-M BMII in electrolyte. Future developments in this research could focus on further fine-tuning these parameters for improved efficiency and exploring additional innovations in DSSC technology, ultimately contributing to the advancement of sustainable and efficient solar energy conversion systems. [ABSTRACT FROM AUTHOR]

Dye-sensitized solar cells (DSSCs) provide a promising alternative to traditional solar technologies, as they offer a unique mix of cost-effectiveness, adaptability, and the possibility of achieving high efficiency. This study aims to investigate the effect of SiO2 purity obtained from coal fly ash on the photoelectric performance of DSSCs. The study focuses on varying the purity of extracted SiO2 from coal fly ash as a counter-electrode material and examining its impact on the efficiency of DSSCs. The efficiency of DSSCs was assessed by evaluating the performance of several various SiO2 purity materials for counter-electrode materials. The performance testing of DSSCs revealed that the counter electrode material, consisting of artificial SiO2 with a purity of 99.9%, achieved the highest efficiency of 0.0113%. Subsequently, DSSCs were fabricated using counter-electrode materials derived from coal fly ash with a purity of 52.91%. These DSSCs demonstrated an efficiency of 0.0076%. DSSCs utilizing SiO2 with a purity of 91.20% exhibited an efficiency of 0.0062%. Dye-sensitized solar cells utilizing a counter electrode material composed of SiO2 with a purity level of 72.54% demonstrated an efficiency of 0.0061%. The results showed that the level of SiO2 purity obtained from coal fly ash has a substantial impact on the photoelectric performance of DSSCs, since higher purity of SiO2 is associated with improved efficiency. [ABSTRACT FROM AUTHOR]

We report the synthesis of phosphorus (P)-doped reduced graphene oxide (P-rGO) using a hydrothermal method at 180°C for 7 h. Furthermore, the amorphous nature and phase purity of the hydrothermally synthesized P-rGO was studied by powder x-ray diffraction. The characteristic sheet-like surface structure of the P-rGO was confirmed by scanning electron microscopy. The presence of P in the P-rGO was authenticated by using energy-dispersive x-ray spectroscopy and photoelectron x-ray spectroscopy. The synthesized P-rGO was employed as a low-cost and Pt-free counter electrode material for the construction of dye-sensitized solar cells (DSSCs). The effect of annealing temperature on the construction of the DSSCs using P-rGO was also studied, and the highest power conversion efficiency of 6.3% and photocurrent density of 15.37 mA/cm2 were obtained at 200°C. The platinum counter electrode-based DSSCs exhibited the power conversion efficiency of 7.4%. The performance of the P-rGO counter electrode-based DSSCs was reasonable and can be further improved by developing novel device architectures. This work proposes the simple, eco-friendly, and Pt-free counter electrode for the construction of DSSCs with a decent performance. [ABSTRACT FROM AUTHOR]

This work is focused on fabricating a counter electrode (CE) for application in a dye-sensitized solar cell (DSSC). Cobalt manganese oxide (CoMn2O4) nanoparticles (NPs) and its nanocomposite with graphene were prepared by a hydrothermal method. The nanocomposites of cobalt manganese oxide with graphene as CoMn2O4/(graphene)x (where x = 0.2, 0.4, and 0.6) were synthesized as an electrode material, and a cell was fabricated for the x = 0.6 nanocomposite to investigate the activity for use in DSSCs. These nanocomposites were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDX), and Fourier transform infrared (FTIR) spectroscopy. SEM analysis revealed the nature of the particles, and the average grain size was in good agreement with XRD results. EDX showed the ratio of the respective samples. The XRD pattern showed the hexagonal structure of CoMn2O4 NPs with an average size of 39.45 nm. The FTIR spectrum indicated O–H stretching bonds and the vibrational bending of MnO at the interstitial sites. For electrochemical analysis, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were performed. Through CV analysis, an anodic peak current (Ipa) was observed at 41.42 µA, while the cathodic peak current (Ipc) was observed at −37.13 µA, and peak-to-peak separation (ΔEpp) = 0.31 V for CoMn2O4 NPs. For graphene, Ipa = 180.45 µA, Ipc = −230 µA, and ΔEpp = 0.25 V, while Ipa = 100.23 µA, Ipc = 80.65 µA, and ΔEpp = 0.16 V for the CoMn2O4/graphene (x = 0.6) nanocomposite, which also showed excellent electrocatalytic properties. The charge transfer mechanism on the surface of the electrode was found to have rapid oxidation–reduction behavior and can be used as an alternative to platinum as the CE in the DSSC. The CV analysis of the CoMn2O4/graphene (x = 0.6) nanocomposite-based DSSC showed that the Ipa current was observed at 26.85 mA, while the Ipc current was observed at −27.25 mA in the two-electrode system. The Rs values for CoMn2O4/graphene with x = 0.2, 0.4, and 0.6 were 142.80 Ω, 141.33 Ω, 135.18 Ω, and 131.18 Ω, respectively, as an electrode material. The exchange current density J = 2.13 × 10−3 A/cm2 was found using the charge transfer resistance value (Rct = 6.03 Ω cm2) and was verified by the Tafel curve. [ABSTRACT FROM AUTHOR]

In this work, we evaluate the bonding characteristics and interfacial electron transfer dynamics of three heteroleptic ruthenium photosensitizers featuring different terpyridine (tpy) acceptor end configurations through quantum-chemical calculations. These photosensitizers feature tpy ligands with a mono/tricarboxylic acid or a phenyl-carboxylic acid anchor and a trans-disposed –NCS and N-heterocyclic carbene ligand in a C^N donor set. Adiabatic transitions reveal significant overlap between higher-excited and ground-state orbitals and correlate with the experimentally observed anti-Kasha fluorescence. In all complexes, two carboxylate-O atoms of the central anchor effectively bind with TiO2 by bridging two titanium sites. However, appending an additional anchor on each peripheral pyridine of tpy renders binding through only one anchor's –C＝O atom to TiO2. Contrary to the complex bearing three anchors, those featuring monocarboxylate-functionalized tpy exhibit faster electron injection within 100 fs. In all, this study provides insights into the photosensitization attributes of the ruthenium complexes for dye-sensitized solar cells. [ABSTRACT FROM AUTHOR]

ABSTRACT The synergistic influence of the LSPR (localized surface plasmon resonance) of gold nanoparticles (Au NPs) and the effect of nitrogen and chlorine co‐doped carbon dots (Cl/N‐CQDs) on dye‐sensitized solar cells (DSSCs) performance are investigated. The gold NPs are coated with a thin layer of Cl/N‐CQDs to produce the Au@Cl/N‐CQDs structure. DSSCs are fabricated by using Au@Cl/N‐CQDs as co‐sensitizer. The focus of this work is to examine the effects of plasmonic Au NPs and carbon dots in addition to their synergistic effect by capping the Au NPs with Cl/N‐CQDs, and track their influence in DSSCs. N719 as ruthenium‐based dye, and natural dyes including betanin, crocin, carthamin, curcumin, chlorophyll, mallow, and lawsone are selected and applied in the DSSCs co‐sensitized by Au@Cl/N‐CQDs. The power conversion efficiency (PCE) of DSSCs using all of the selected dyes is enhanced upon using the Au@Cl/N‐CQDs. It is due to the improvement in VOC (open circuit voltage) and JSC (short circuit photocurrent densities) relative to the use of dyes alone. Based on computational results, Au@Cl/N‐CQDs cause a red‐shift in comparison with pure dyes. The TD‐DFT (time‐dependent density functional theory) results show that the orbitals from the Au@Cl/N‐CQDs in dye/Au@Cl/N‐CQDs have contribution in most of the absorptions. In other words, electrons from HOMO (highest occupied molecular orbital) of Au@Cl/N‐CQDs is transferred to the LUMO (lowest unoccupied molecular orbital) of dye, in most cases. [ABSTRACT FROM AUTHOR]

Light harvesting materials are crucial for capturing the sunlight in a device such as a solar cell for better efficiency. In this study, we developed high surface area, submicron-sized TiO2 spheres (MTS) incorporated with anisotropic Au nanoparticles (Au_MTS) to create highly light-absorbing photoanodes for enhanced dye-sensitized solar cell (DSSC) efficiency. The high surface area of MTS (~125 m2/g) allows for increased dye-loading, while their submicron size (150-300 nm) provides superior light-scattering capabilities for significantly enhancing the photoanode's light absorption. Furthermore, incorporating of anisotropic Au nanoparticles enables broadband surface plasmon resonance (SPR) coupling, synergistically boosting photon harvesting in the Au_MTS photoanodes. The interconnected tiny TiO2 nanoparticle network in MTS supports charge carrier generation and transport, providing ample sites for dye adsorption and efficient electron pathways. Au_MTS with varying amounts of Au nanoparticles synthesized by a greener microwave-assisted synthesis method and DSSC devices were fabricated and compared with devices made from pristine MTS and P25 nanoparticles. The optimal Au_MTS device, containing ~1.3 wt% Au nanoparticles, achieved a maximum power conversion efficiency (PCE) of ~7.7%, representing improvements of ~40% and ~60% over pristine MTS (PCE of ~5.2%) and P25 nanoparticles (PCE of ~4.71%), respectively. Overall, this work demonstrates the effectiveness of plasmonic mesoporous photoanodes in enhancing DSSC performance through improved photo response, light scattering, and dye loading. [ABSTRACT FROM AUTHOR]

Tin oxide (SnO2) nanostructure thin film was synthesized on glass and FTO glass substrates at 450∘C with flow rates of Argon and oxygen (8L/h) using the atmospheric pressure chemical vapor deposition (APCVD) method. The surface morphology, structure and optical properties of SnO2 film were depicted by Field Emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD) and UV–Visible (UV–Vis) spectroscopy, respectively. The optical band gap of SnO2 film was found to be 3.72eV. In addition, a layer of titanium oxide was deposited on the SnO2 film using a screen printing method. Then, the anodic electrode was immersed in the dye to complete cell manufacturing. It was found that the short circuit current, open circuit voltage and fill factor in the case of the prepared dye-sensitized solar cell (DSSC) were 8.7mA/cm2, 0.85V and 0.583, respectively, which led to the efficiency of 4.3. It was also found that the optical response speed of the prepared photoanode showed a periodic response and a high on/off ratio. [ABSTRACT FROM AUTHOR]

The versatile absorption and fluorescence properties alongside the outstanding chemical and photostability make the rylene‐based derivatives one of the most investigated compounds in the field of third‐generation solar cells. Over the last 25 years, an intensive research activity has made the rylene‐based derivatives one of the most interesting and modular class of sensitizers in the dye‐sensitized solar cells. This critical analysis compares and discusses the state of the art of the rylene‐based dyes, starting from the pioneering studies on the perylene bisimides to the latest N‐annulated rylene derivatives. The focus of this review is to discuss the structure‐to‐properties relationship highlighting how critical points have been overcome and what are the most recent approaches toward the achievement of novel record efficiencies in the dye‐sensitized solar cells. [ABSTRACT FROM AUTHOR]

Tungsten-doped TiO2 thin films were prepared by sol–gel method on fluorine-doped tin oxide-coated substrates as working electrodes of dye-sensitized solar cells. The influences of different W doping (0, 2, 4, 6, and 8 at%) on the microstructure, optical, and photovoltaic properties of the W-TiO2 thin-film DSSCs were studied by the measurement of X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET) analysis, and electrochemical impedance spectroscopy (EIS). An optimal DSSCs performance was observed with a 6 at% W-doped TiO2 thin film, resulting in a Voc of 0.68 V, a Jsc of 20.2 mA/cm2, an FF of 68.6%, and an efficiency (η) of 9.42%. The efficiency of DSSCs with 6 at% W-doped TiO2 photoanode improved by 75%. This is because the 6 at% W-doped TiO2 thin film increases the specific surface area and electron transfer rate. [ABSTRACT FROM AUTHOR]

We developed dye-sensitized solar cells (DSSCs) using 1,5-carboxy-2-[[3-[(2,3-dihydro-1,1-dimethyl-3-ethyl-1H-benzo[e]indol-2-ylidene)methyl]-2-hydroxy-4-oxo-2-cyclobuten-1-ylidene]methyl]-3,3-dimethyl-1-octyl-3H-indolium and 1,3,3-trimethyl indolino-6′-nitrobenzopyrylospiran. The DSSCs incorporate photochromic molecules to regulate photoelectric conversion properties. We irradiated photoelectrodes adsorbed with SQ2/SPNO2 using both UV and visible light and observed the color changes in these photoelectrodes. Following UV irradiation, the transmittance at 540 nm decreased by 20%, while it increased by 15% after visible light irradiation. This indicates that SPNO2 on the DSSCs is photoisomerized from the spiropyran form (SP) to the photomerocyanine (PMC) form under UV light. The photoelectric conversion efficiency (η) of the DSSCs increased by 0.15% following 5 min of UV irradiation and decreased by 0.07% after 5 min of visible light irradiation. However, direct electron injection from PMC seems challenging, suggesting that the mechanism for improved photoelectric conversion in these DSSCs is likely due to Förster resonance energy transfer (FRET) from PMC to the SQ2 dye. The findings suggest that the co-sensitization of DSSCs by PMC-SQ2 and SQ2 alone, facilitated by their respective photoabsorption, results in externally responsive and co-sensitized solar cells. This study provides valuable insights into the development of advanced DSSCs with externally controllable photoelectric conversion properties via the strategic use of photochromic molecules and energy transfer mechanisms, advancing future solar energy applications. [ABSTRACT FROM AUTHOR]

Conducting polymers are emerging as promising alternatives to rare and expensive platinum for counter electrodes in dye-sensitized solar cells; due to their ease of synthesis, they can be chemically tuned and are suitable for roll-to-roll production. Among these, poly (3,4-ethylenedioxythiophene) (PEDOT)-based counter electrodes have shown leading photovoltaic performance. However, certain conductivity issues remain that affect the effectiveness of these counter electrodes. In this study, we present an electropolymerized PEDOT and poly(N-alkylated-carbazole) copolymer as an efficient electrocatalyst for the reduction in I 3 − in dye-sensitized solar cells. Copolymerization with N-alkylated carbazoles significantly increases the conductivity of the polymer film and facilitates rapid charge transport at the interface between the polymer electrode and the electrolyte. The length of the alkyl substituents also plays a crucial role in this improvement. Electrochemical analysis showed a reduction in charge transport resistance from 3.31 Ω·cm2 for PEDOT to 2.26 Ω·cm2 for the PEDOT:poly(N-octylcarbazole) copolymer, which is almost half the resistance of a platinum-based counter electrode (4.12 Ω·cm2). Photovoltaic measurements showed that the solar cell with the PEDOT:poly(N-octylcarbazole) counter electrode achieved an efficiency of 8.88%, outperforming both PEDOT (7.90%) and platinum-based devices (7.57%). [ABSTRACT FROM AUTHOR]

ABSTRACT The strategy of isosteric replacement of the benzene ring with a thiophene core was applied in the design of phthalocyanine 1 with the aim for reaching an effective organic chromophore as employable content in organic photovoltaic devices. The formation of the desired product was not achieved but the approach created organic small‐molecules 2 and 3. These, representing the reactive intermediates, were converted to novel hemiphthalocyanine 4. Although undesired, all exhibit absorbance in the visible region (λmax ~ 400 nm) and proximity of the HOMO/LUMO band edge (Eg: 2.0–3.5 eV), suggesting that compounds 2–4 behaves as an effective π‐conjugated linkers in donor‐π‐acceptor type dyes for dye sensitized solar cells and related high performing energetic devices. [ABSTRACT FROM AUTHOR]

Dye-sensitized solar cells (DSSCs) are a type of thin-film solar cell that has been extensively studied for more than two decades due to their low manufacturing cost, flexibility and ability to operate under low-light conditions. However, there are some challenges that need to be addressed, such as energy losses, material integration, weak photocurrent generation and stability, to enhance the performance of DSSCs. One of the approaches to enhance the performance of DSSCs is the use of luminescent materials. These are materials that can absorb light and re-emit at different wavelengths, allowing the conversion of ultraviolet (UV) and near-infrared (NIR) light, which DSSCs do not efficiently utilize, into visible light that can be absorbed. The main objective of this article is to provide an in-depth review of the impact of luminescent materials in DSSCs. Research interest on luminescent materials, particularly down conversion, up-conversion and quantum dots, was analyzed using data from the "Web of Science". It revealed a remarkable number of over 200,000 publications in the past decade. Therefore, the state of the art of luminescent materials for enhancing the performance of the solar cells was reviewed, which showed significant potential in enhancing the performance of DSSCs. [ABSTRACT FROM AUTHOR]

Combustion of coal at thermal power plants generates enormous amounts of coal fly ash (CFA). Proper disposal of CFA is an important issue today because environmental problems are considered a burning issue worldwide. On the other hand, groundnut shells (GNS), regarded as agricultural waste in general, litter landfills everywhere and create soil degradation. Since both CFA and GNS contain abundant silica, this work focuses on extracting amorphous silica from these materials through a total dissolution–precipitation process. The silica was extracted from it and used to prepare titanium oxide (TiO₂) hybrids. The GNSS were extracted from GNS, and the CFAS was extracted from the CFA. The methods used were based on sol–gel. These hybrids were further tested for the performance of their solar cells in dissolving dyes. The overall results of the obtained physical properties of CFAS and GNSS are similar to those of conventional silica. More importantly, TiO₂/GNSS and TiO₂/CFAS hybrids showed enhanced photocatalytic efficiency compared to the pure TiO₂. Therefore, it is evidence of repurposing CFA and GNS, which have high potential for use as sustainable applications in renewable energy and environmental remediation. [ABSTRACT FROM AUTHOR]

Currently energy crisis is one of the challenging issues worldwide. As such, generation of green alternative energy should take the attention of researchers around the globe. This work reports synthesis of zinc oxide nanoparticles (ZnO NPs) using biological method (using fruit extract of Ruta chalepensis) for photoanode of dye sensitized solar cells (DSSCs). In the study, the performance of DSSCs derived from chemically synthesized and biologically synthesized ZnO NPs were evaluated. The plant extract templated synthesis of ZnO NPs were prepared in varied zinc nitrate to R. chalepensis fruit extract ratios of 1 : 2,1 : 1, and 2 : 1 and labeled as g‐ZnO(1 : 2), g‐ZnO(1 : 1) and g‐ZnO(2 : 1); and that of chemically synthesized ZnO NPs is labelled as c‐ZnO (as a control). Thermogravimetric analysis‐differential thermal analysis (TGA/DTA) reveals that ZnO NPs are stable above 450 °C. From X‐ray diffraction (XRD) pattern, average size of g‐ZnO(1 : 2), g‐ZnO(1 : 1), g‐ZnO(2 : 1) and c‐ZnO NPs were estimated to be 7, 13, 18 and 26 nm, respectively. Scanning electron microscopy (SEM) reveals the presence of ZnO in clustered, flake‐like, and some agglomerated spherical forms; and energy dispersive spectroscopy (EDX) confirms presence of Zn and O atoms in the sample. The optical band gaps of g‐ZnO (1 : 2), g‐ZnO(1 : 1), g‐ZnO(2 : 1) and c‐ZnO NPs were measured to be 3.30, 3.25, 3.23 and 3.22 eV respectively using ultraviolet‐visible (UV‐Vis) absorbance spectrophotometer. Fourier transform infrared (FT‐IR) spectroscopic analysis shows the absorption band for Zn−O bonding between 400 and 600 cm−1. The produced photoanode, crystal violet dye, quasi‐solid‐state electrolyte, and counter electrode were used to fabricate DSSCs. The power conversion efficiency (PCE) of the constructed DSSC device with a c‐ZnO photoanode is 1.95 %, and those with a g‐ZnO (2 : 1), g‐ZnO(1 : 1), and g‐ZnO(1 : 2) photoanodes have PCE of 1.9 %, 1.36 %, and 0.215 % respectively. [ABSTRACT FROM AUTHOR]

A solar photovoltaic (PV) cell, is an electrical device that uses the PV effect to convert light energy into electricity. The application of oyster mushroom dyes in dye sensitized solar cell (DSSC) is a novel strategy to substitute the costly chemical production process with easily extractable, environmentally acceptable dyes. Both dyes of yellow and pink oyster mushrooms were extracted using the same process but dried into powder form using two techniques, warm drying and freeze drying. The characterization was carried out utilizing current-voltage (I-V) characterization for electrical properties, Ultraviolet-Visible (UV-Vis) spectrophotometer for optical properties, Field Emission Scanning Electron Microscopy (FESEM), and Atomic Force Microscopy (AFM) for the structural properties. It was found that freeze-dried pink and yellow oyster mushroom had shown the good properties for DSSC application as it produced energy bandgap which lies within the range of efficient dye sensitizer; 1.7 eV and 2.2 eV, the most uniform distribution of pores and a nearly spherical form in FESEM analysis, and AFM result obtained with the highest root mean square (RMS) roughness value (26.922 and 34.033) with stereoscopic morphologies. The data proved that mushroom dyes can be incorporated in DSSC with the optimization of drying method in the extraction process, dilution of dye and the layer of deposition on the glass substrate. The current density-voltage (J–V) characteristics of fabricated DSSC was characterized using Newport Oriel Sol3A solar simulator under AM 1.5 Sun condition (100 mW/cm2, 25 oC). From the result obtained by solar simulator, the fabricated FTO/TiO2/Pleurotus djamor dye/Pt indicated the Voc of 0.499 V and Jsc of 0.397 mA/cm2. [ABSTRACT FROM AUTHOR]

Context: 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. Methods: 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 ( A ∘ ), H index ( A ∘ ), ∆( A ∘ ), t index ( A ∘ ), 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. [ABSTRACT FROM AUTHOR]

GaAs thin‐film solar cells have high efficiency, reliability, and operational stability, making them a promising solution for self‐powered skin‐conformal biosensors. However, inherent device thickness limits suitability for such applications, making them uncomfortable and unreliable in flexural environments. Therefore, reducing the flexural rigidity becomes crucial for integration with skin‐compatible electronic devices. Herein, this study demonstrated a novel one‐step surface modification bonding methodology, allowing a streamlined transfer process of ultra‐thin (2.3 µm thick) GaAs solar cells on flexible polymer substrates. This reproducible technique enables strong bonding between dissimilar materials (GaAs‐polydimethylsiloxane, PDMS) without high external pressures and temperatures. The fabricated solar cell showed exceptional performance with an open‐circuit voltage of 1.018 V, short‐circuit current density of 20.641 mA cm−2, fill factor of 79.83%, and power conversion efficiency of 16.77%. To prove the concept, the solar cell is integrated with a skin‐compatible organic electrochemical transistor (OECT). Competitive electrical outputs of GaAs solar cells enabled high current levels of OECT under subtle light intensities lower than 50 mW cm−2, which demonstrates a self‐powered electrocardiogram sensor with low noise (signal‐to‐noise ratio of 32.68 dB). Overall, this study presents a promising solution for the development of free‐form and comfortable device structures that can continuously power wearable devices and biosensors. [ABSTRACT FROM AUTHOR]

Solar-driven CO2 conversion into high-value-added chemicals, powered by photovoltaics, is a promising technology for alleviating the global energy crisis and achieving carbon neutrality. However, most of these endeavors focus on CO2 electroreduction to small-molecule fuels such as CO and ethanol. In this paper, inspired by the photosynthesis of green plants and artificial photosynthesis for the electroreduction of CO2 into value-added fuel, CO2 artificial photosynthesis for the electrocarboxylation of bromobenzene (BB) with CO2 to generate the value-added carboxylation product methyl benzoate (MB) is demonstrated. Using two series-connected dye-sensitized photovoltaics and high-performance catalyst Ag electrodes, our artificial photosynthesis system achieves a 61.1% Faraday efficiency (FE) for carboxylation product MB and stability of the whole artificial photosynthesis for up to 4 h. In addition, this work provides a promising approach for the artificial photosynthesis of CO2 electrocarboxylation into high-value chemicals using renewable energy sources. [ABSTRACT FROM AUTHOR]

Novel D‐A1‐A2‐π‐A organic sensitizers (FZ‐sensitizer), utilizing spiro [fluorene‐9,9′‐phenanthren]‐10′‐one and benzo [c][1,2,5]thiadiazole moiety as two auxiliary acceptors, are synthesized and applied in dye‐sensitized solar cells (DSSCs) and hydrogen production. By incorporating a bulky spiro [fluorene‐9,9′‐phenanthrene]‐10′‐one (A1) and benzo[c][1,2,5]thiadiazole (A2) between the donor (D) and π‐bridge moiety, structural modifications inhibit molecular aggregation, while the carbonyl group enhances the capture of Li+ ions, thereby delaying charge recombination. Furthermore, the extended π‐conjugation broadens the light absorption range and enhances the power conversion efficiency (PCE) of FZ‐2 under AM1.5 conditions, achieving up to 5.72%. Co‐sensitization with N719 and FZ‐2 shows PCE of 9.60% under one sun. Under TL84 indoor light conditions, the efficiency is 29.69% at 2500 lux. The superior co‐sensitization performance of N719 and FZ‐2 can be attributed to FZ‐2′s high absorptivity at short wavelengths, compensating for N719′s shortcomings in this range. FZ‐sensitizers also exhibit high efficiency in photocatalytic hydrogen production. The hydrogen production activities of FZ‐2 are 9190 μmol/g (1 hour) and 76582 μmol/g (12 hours) respectively, while those of FZ‐1 are 7430 μmol/g (1 hour) and 64004 μmol/g (12 hours), indicating that FZ‐2 can inject charges into TiO2 more efficiently and utilize them for water splitting. Stability testing of photocatalytic water splitting after 12 hours shows a turnover number (TON) of 4249 for FZ‐1 and 5378 for FZ‐2. [ABSTRACT FROM AUTHOR]

In order to study the connection between structure of the molecular and sensitizing performance in dye-sensitized solar cells, four new organic sensitizers with donor-pi spacer-acceptor structures were designed and synthesized. The structural characterization of all dye sensitizers was investigated using FT-IR, 13C and 1H NMR, CHN and UV–visible analyses. The electronic orbital transitions and optical properties were determined and discussed. (E)-2-cyano-3-(5-(3-(di-p-tolylamino)phenyl)furan-2-yl)acrylic acid (TPCA), (Z)-2-cyano-N′-((5-(3-(di-p-tolylamino)phenyl)furan-2-yl)acetohydrazide (TPCH), (E)-3-(5-(4-(bis(4-methoxyphenyl)amino)phenyl)furan-2-yl)-2-cyanoacrylic acid (MTPCA), and (Z)-N′-((5-(4-(bis(4-methoxyphenyl)amino)phenyl)furan-2-yl)methylene)-2-cyanoacetohydrazide exhibited band gaps (Egap) in the range from 1.51 to 1.78 eV with λabs in the range of 486–589 nm. The dyes' energy levels were investigated using the cyclic voltammetry technique and DFT calculations. To complement the comprehensive optical, electrochemical, and photovoltaic properties, density functional theory studies were conducted. Besides, important parameters such as open-circuit voltage, light harvesting efficiency, and band gap energy of the dye sensitizers were calculated and discussed. The theoretically calculated open-circuit voltage (Voc) values ranged from 1.28 to 2.04 eV, while the light-harvesting efficiency (LHE) values varied from 0.11 to 0.22. Indeed, this theoretical research could guide chemists to synthesize effective dyes for DSSCs. [ABSTRACT FROM AUTHOR]

A series of novel gel polymer electrolytes (GPEs) was developed for quasi-solid-state dye-sensitized solar cells (DSSCs), to enhance their performance via mixed counterion effect. Here, LiI, CsI, tetrahexylammonium iodide (Hex4NI), and 1-methyl-3-propylimidazolium iodide (MPII) were used as iodide salts for the preparation of this new GPE. The electrolyte series was investigated by varying the molar fractions of LiI and CsI, keeping the molar fractions of Hex4NI and MPII constant. The molar composition of the iodide salts in electrolytes is MPII0.25(Hex4NI)0.8CsI(2-x)LiIx, where x is the variable. The temperature dependence of conductivity showed Vogel-Tammann-Fulcher behavior. The sample with x = 0.72, where LiI to CsI to Hex4NI to MPII molar ratio is 72:48:80:25, which gave 8.42 mS cm−1 at 30 °C, displayed the maximum conductivity at all the temperatures. The dependence of the complex AC conductivity on frequency is examined in detail to study the impacts of dielectric polarization effects of the GPEs. Quasi-solid-state DSSCs were constructed by utilizing six-layered TiO2 photoelectrodes, Pt counter electrode, and the novel GPE series. The three-salt electrolytes, containing LiI only and CsI only, containing DSSC showed efficiencies of 5.72% and 3.53% respectively. The four-salt system, which is composed of LiI to CsI to Hex4NI to MPII with a molar ratio of 96:24:80:25, demonstrated the highest solar cell efficiency of 7.42%, due to the collective contribution of Hex4N+, MPI+, Cs+, and Li+ ions in improving the charge transport in the electrolyte system. This study shows that DSSC performance can greatly be improved by optimizing counterion ratios without changing total ions in the electrolyte. [ABSTRACT FROM AUTHOR]

We have developed new derivatives of Ruthenium metal complex-based dyes for use as sensitizers in DSSCs. Theoretical investigations have been conducted on ten Ruthenium metal complex clusters to analyse their geometries, electronic structures, density of states, optical properties, photovoltaic properties, and electrochemical properties. These investigations were carried out using the Density Functional Theory (DFT) and Time-Dependent Density Functional Theory (TD-DFT) methods. The objective was to design novel ligands that enhance the performance of dyes in dye-sensitized solar cells. We evaluated the impact of various chalcogen atoms in the ligand donor moieties, using different aromatic annulenes as building blocks. Additionally, we examined the influence of different functional groups connected to the bipyridyl unit in the ligand acceptor moiety. The designed dyes exhibit red-shifted spectra and improved electron transition abilities compared to other dyes, resulting in more effective intramolecular charge transfer upon photo-excitation. This suggests that these dyes would deliver the best photovoltaic performance. Furthermore, the designed dyes demonstrate a significantly enhanced light-harvesting efficiency, a higher open-circuit voltage (), a greater short-circuit current, and favourable electrochemical properties. These characteristics are crucial for achieving faster electron injection efficiency and higher performance in photovoltaic devices. [ABSTRACT FROM AUTHOR]

Our study aimed to evaluate the efficiency of solar power systems by developing dye-sensitized solar cells (DSSCs) with an electrolyte of carbon nanotubes (CNTs) dispersed in poly (methyl methacrylate) (PMMA). Photovoltaic and impedance spectral studies showed that a polymer electrolyte with 3% carbon nanotubes resulted in an efficiency of solar power conversion of 7.40% and a photovoltaic current per unit cross-sectional area of 17.13 mA/cm2 in DSSCs. The optimal distribution of CNT fillers decreased the charge recombination of the titanium dioxide-dye-CNT-PMMA electrolyte surface. The X-ray diffraction spectrum showed characteristic peaks of PMMA and CNT at 28.6° and 63.0°, respectively, obtained in pure form and composites with dispersed carbon nanotubes. The peak intensity increased with the addition of CNTs in the polymer. A Fourier transform infrared spectroscopy investigation revealed the bonding within the CO and CH of PMMA and CNT to the polymer composite. The dielectric constant increased from 2.9 to 4.4, and the dielectric loss increased from 0.10 to 0.90 at 1 MHz for the dispersion of 6% CNT in PMMA. Scanning electron microscopy analysis showed that the internal particle structure and porosity had changed due to the presence of the CNTs in the PMMA. The dispersion of CNTs into the PMMA increased the maximum voltage of the polymer electrolytes. A breakdown voltage of 7.4 kV was attained with 6% CNTs in the polymer. [ABSTRACT FROM AUTHOR]

[Display omitted] Photoelectrochemical (PEC) water splitting is an effective and sustainable method for solar energy harvesting. However, the technology is still far away from practical application because of the high cost and low efficiency. Here, we report a low-cost, stable and high-performing industrial-Si-based photoanode (n -Indus-Si/Co -2mA-xs) that is fabricated by simple electrodeposition. Systematic characterizations such as scanning electron microscopy, X-ray photoelectron spectroscopy have been employed to characterize and understand the working mechanisms of this photoanode. The uniform and adherent dispersion of co-catalyst particles result in high built-in electric field, reduced charge transfer resistance, and abundant active sites. The core–shell structure of co-catalyst particles is formed after the activation process. The reconstructed morphology and modified chemical states of the surface co-catalyst particles improve the separation and transfer of charges, and the reaction kinetics for water oxidation greatly. Our work demonstrates that large-scale PEC water splitting can be achieved by engineering the industrial-Si-based photoelectrode, which shall guide the development of solar energy conversion in the industry. [ABSTRACT FROM AUTHOR]

This research paper reports the fabrication and evaluation of titanium dioxide (TiO2)- and zinc oxide (ZnO)-based dye-sensitized solar cells with anthocyanin dye extracted from pomegranate. TiO2 and ZnO were synthesized using the hydrothermal synthesis and chemical bath deposition techniques, respectively. The scanning electron microscopy analysis showed that TiO2 had nanopillars made up of nano rods with dimensions of 111.866, 90.521, and 81.908 nm, while ZnO had hexagonal patterned nanorods with lengths of 283.294 nm and diameters of 91.782 nm. The absorption spectra of the pomegranate dye were analysed and the strongest absorption peak was found to be at 520 nm, which corresponds to the existing anthocyanin pigment. The band gap of pomegranate dye was noted down to be 2.45 eV. The performance of the dye-sensitized solar cells was evaluated using one sun illumination (100 mW/cm2) where the dye-sensitized solar cell with TiO2 nanopillars achieved an improved efficiency of 0.46% whereas the dye-sensitized solar cell with ZnO nanorods showed a considerably reduced efficiency of 0.42%. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The two technologies of dye-sensitized solar cells (DSSCs) and organic light-emitting devices (OLEDs) are emerging in the development of new sources of energy and lighting, respectively. The exceptional features of these technologies, including their color, insensitivity to temperature, and high response angle, have caused their attention and development. Organic compounds play a key role in these two technologies and cause the effective response and stability of the device, so high stability, longevity, and the possibility of simple application in the structure of the structure are of great importance. Molecular engineering and the application of various substitutions to the naphthalimide core can produce promising results for the preparation of stable organic materials with diversity in properties. In this review, naphthalimides are introduced as an effective core in the preparation of lightand electricity-sensitive dyes. Its application in two technologies, DSSCs and OLED, is explained, and the different components of these technologies are briefly introduced. One of the highest efficiencies reported for dye-sensitized solar cells based on naphthalimide as photosensitizers is 10.8 %. This sensitizer has alkyl and indoline groups. Different structures of arrangement of electron donor and electron acceptor groups will be investigated and the performance efficiency of these devices will also be investigated. Studies show that the amino group is an important substitution in the preparation of naphthalamide fluorescent dyes. The presence of this group will increase the efficiency of the amplifier by up to 10 %. [ABSTRACT FROM AUTHOR]

This research focused on developing photoanodes for dye-sensitized solar cells (DSSCs) by combining titanium dioxide (TiO2), layered double hydroxide (LDH), and TiO2-LDH composites. DSSCs were fabricated using different photoanode materials, including TiO2, LDH, and various TiO2-LDH ratios sensitized with N719 dye and employing an iodide/triiodide redox couple electrolyte. Under simulated sunlight, TiO2-based DSSCs achieved an impressive 4.57% energy conversion efficiency, while LDH-based devices only reached 0.62%. DSSCs with varying TiO2-LDH ratios demonstrated efficiencies of 2.4%, 3.2%, and 3.3% for 1:1, 1:3, and 1:5 ratios, respectively. The superior performance of TiO2-based DSSCs was attributed to higher electron transfer efficiency. Dye loading analysis revealed that TiO2 had the highest dye loading due to its extensive surface area, while LDH had the lowest loading. Adsorption kinetics of N719 dye on TiO2 and LDH films indicated a pseudo-second-order model, suggesting chemical interactions between dye molecules and surface sites. [ABSTRACT FROM AUTHOR]

The enormous amount of solar power and its state-of-the-art capturing technology that produces electricity, increases the grid interconnection rate of photovoltaic (PV) plants. Prior knowledge of the aperiodic characteristics of solar energy received by the Earth’s surface is essential for PV plants to ensure reliable operation and stable, secure grid connections. Power generation under diffused sunlight by PV plants with the most widely used first-generation solar cells has significant limitations. A dye-sensitized solar plant (DSSP), utilizes dye-sensitized solar cell (DSSC) technology, remains active in low light conditions. Though the activeness enables such plants to generate electricity throughout the year while receiving diffuse sunlight, unlike conventional solar technologies the plants have a requirement of knowledge of future power generation. This could be the first paper to report on the generated power forecast for such plants. The study has utilized a machine learning approach with a proposed DSSP model for the forecast. Spyder, an open-source integrated development environment, is the test workbench for the experimentation. The results show the robustness and reliability of the method, regardless of the weather conditions in the test area. The DSSP, along with the prediction model, will moderately overcome the shortcomings of power generation under diffuse daylight with intermittent solar radiation and grid connections. [ABSTRACT FROM AUTHOR]

AbstractDye-sensitized solar cells (DSSCs) have garnered significant attention due to their exceptional ability to convert solar energy into electricity at a relatively low cost. Novel organic photosensitizers (FZB1-FZB9) from the pyrazine-based aromatic dye (E)-3-(5-(2,3-bis(40-(diphenylamino)-[1,10-biphenyl]-4-yl)-7 (trifluoromethyl)quinoxalin-5-yl)thiophen-2-yl)-2-cyanoacrylic acid (TPPF) have been quantum chemically modeled for their application in dye-sensitized nanocrystalline TiO2 solar cells (DSSCs). The electrochemical and photovoltaic features of modeled dyes are investigated by performing DFT insights, i.e. FMOs, absorption maxima, DOS, TDM, NBO, exciton and binding energy, radiative lifetime analysis (ꚍ), electron-injection (ΔGinject) and regeneration analysis (ΔGdyeregen)@TiO2. FMO analysis confirmed the better electron injection as HOMO of designed dyes was found to be more positive than redox potential I/I3 (-4.8 eV), and the LUMO appeared more negative than the conduction band of TiO2 (-4.0 eV). The modeled photosensitizers exhibited red shift λmax from 338-494 nm with a lower energy gap from 5.62 eV in FZB (R) to 5.17 eV in FZB9. Bridging modification reduces the exciton and binding energy for designed dye FZB9 and FZB7 compared to reference FZB. The designed dyes appeared with a lower radiative lifetime of up to 1.32 than the reference dye of 1.63, better light harvesting efficiency (LHE), and the highest NBO charge on bridges of designed photosensitizers for enhanced light emitting efficiency. The investigated dyes exhibited more negative values for electron injection, i.e. −0.003 and the highest values of dye regeneration (ΔGregedyeregen) up to 11.717, which unveils innovative and effective injection of electrons toward semiconductor TiO2. Among all dyes, FZB8 proved best with the novel bridging modification that enables quick charge transfer as exhibited the lowest gap (5.17 eV), lowest excitation energy, better LHE, highest charge on LUMO and more negative electron injection (ΔGinject). The outcomes of this computational study confirmed that this research established a new benchmark for achieving novel and efficient photosensitizers, thus recommending them for future DSSC applications. [ABSTRACT FROM AUTHOR]

This review focuses mostly on organic dye‐sensitized solar cells, as they are an attractive, environmentally friendly alternative to traditional silicon solar cells for the production of renewable energy at a lower cost. The dye chromophore is recognized as the central component of the DSSC device. To improve the electrochemical, photovoltaic, and absorption properties of organic sensitizing dyes, we have designed a series of eight new dyes Pi (i = 1.8) based on the DPA‐2 architecture (the reference molecule). We have investigated the effects of internal absorption of different acceptor groups in D‐Ai‐π‐A before and after binding to the TiO2 cluster surface on the ability to inject electrons into the surface. The benzophenothiazine is the D donor, the π‐spacer is furan, and the A acceptor is cycnoacrylic acid. We are using time‐dependent density functional theory (TD‐DFT), and density functional theory (DFT) in our quantum calculations. It is theoretically possible to predict suitable candidates for the DSSC device and identify correlations between their structure and properties by using DFT and TD‐DFT simulations to thoroughly study in detail electronic structures, natural binding orbital (NBO), analysis of UV‐visible absorption spectra, parameters influencing short‐circuit current density (JSC), open‐circuit voltage (VOC), and intramolecular charge transfer (ICT). Additionally, the relationship between optoelectronic properties and molecular structure was investigated, and the effect of auxiliary acceptor groups (Ai) on the primary photovoltaic properties of the reference molecule DPA‐2. The results show that by changing the internal acceptor to DPA‐2 could create a more coplanar and rigid structure. This would cause the energy gap (Eg) for each of the dyes created to significantly shrink, reducing it from 2.29 to 1.38 eV. The absorption spectra's λmax for each dye would also change color, this was because the acceptor moiety Ai of the phenothiazine moiety changed when it came to DPA‐2 (not including compounds P1 and P4). In contrast, P6 and P7 dyes demonstrate an absorption range beyond 500 nm, implying a more efficient utilization of sunlight in the visible spectrum compared to other dyes. Furthermore, all organic dyes show a robust LHE performance (0.919 to 0.993), correlating with the lowest ΔGreg values (0.097 to 0.356) and the most negative ΔGinject values (−2.067 to −1.121). The power conversion efficiency of PCE and JSC could increase according to these results. Therefore, theoretical research into adding a second internal acceptor group to the D‐Ai‐π‐A structure should produce new methods for improving solar energy output. [ABSTRACT FROM AUTHOR]

Ternary metal oxide materials are being explored as potential electrode materials for dye-sensitized solar cells due to their adjustable electronic band structures through elemental composition modifications. Perovskite materials based on zinc and titanium have been utilised in DSSC and show moderate performance. Considerable research has been dedicated to this field to improve their performances. The focus was primarily on the synthetic variabilities due to their impact on performance under varying synthetic conditions. According to this perspective, no comparative studies have found superior methodologies for utilising zinc titanate as a potential photoanode in DSSC. We synthesised a zinc titanate material using thermal, sol-gel, and plasma irradiation techniques. The materials' structural variability was analysed using PXRD and FT-IR techniques. A mixed-phase composition of spinel cubic and hexagonal has been identified. The SEM images provide insights into the particle distribution and morphology of the zinc titanate materials. Investigating absorption properties, band gap energy levels and aggregation behaviours provided initial insights into the potential use of the three zinc titanate materials. The DSSC devices were fabricated using zinc titanate materials with varying properties, and the results are detailed in this discussion. Based on the findings, the plasma and thermal irradiation techniques yielded more favourable zinc titanate materials for dye-sensitized solar cell use. The efficiency reached 0.04 % when operating with polymeric gel electrolytes. [Display omitted] [ABSTRACT FROM AUTHOR]

This review thoroughly analyzes the progress and challenges in the emerging fields of rare-earth-based upconversion (UC) and downconversion (DC) materials for dye-sensitized solar cells (DSSCs) and perovskite solar cells (PSCs). Despite being outperformed by silicon solar cells in terms of efficiency, DSSCs and PSCs have garnered significant attention owing to their ease of fabrication using low-cost materials, making them promising alternatives for commercial photovoltaic devices. However, their power conversion efficiency (PCE) is limited by significant absorption in the visible region of the solar spectrum, leading to transmission losses of sub-bandgap photons. Rare-earth-doped luminescent materials provide a favorable solution by converting these low-energy photons into high-energy photon, thereby enhancing the light absorption and scattering effects of solar cells. This review delves into the underlying mechanisms of trivalent lanthanide ions, which exhibit exceptional luminescence, photostability, and sharply defined emission lines. The review also discusses the impact of microstructures on the properties and performance of these solar cells, emphasizing the importance of energy band alignment, defect passivation, and charge carrier transport facilitated by rare-earth doping. Additionally, this review covers fabrication techniques and discusses the broader implications of UC and DC materials in advancing future photovoltaic technologies. Further, this review offers a comprehensive perspective on the potential applications and future trends in integrating rare-earth-based materials into solar cells, aiming to maximize their efficiency and commercial viability. [ABSTRACT FROM AUTHOR]

Herein, we demonstrate an optimization of dye-sensitized solar cells (DSSCs) through the development of single-layer and double-layer configurations. Focusing on the incorporation of brookite and anatase phases in varying ratios, the study aims to determine the optimal composition for enhanced photovoltaic performance. The active layer, composed of anatase- and brookite-TiO2 nanoparticles, is further modified with a scattering layer comprising a mixture of anatase nanoparticles and brookite-TiO2 in the form of nanocube or rice-like particles. The synthesis of TiO2 nanostructures with various morphologies and phase compositions and their subsequent application in single-layer and double-layer DSSCs are presented. The results highlight the superior light-harvesting capabilities achieved through the strategic incorporation of brookite phase into the anatase phase, emphasizing the importance of optimizing the anatase: brookite ratio. The single-layer DSSCs exhibit a peak efficiency of 8.73%, achieved with a composition of 30 wt.% brookite and 70 wt.% anatase at a thickness of 15 μ ms. In the context of double-layer DSSCs, the combined optimization of the active layer composition, scattering layer morphology, and utilization of anatase nanoparticles leads to a remarkable efficiency of 9.18%. These findings underscore the critical role of composition and morphology in enhancing the performance of DSSCs, showcasing the potential for brookite-based DSSCs in solar energy conversion. [ABSTRACT FROM AUTHOR]

The film photocatalyst is easily recycled and has attracted the widely research interesting. Here the ferroelectric Hf 0.5 Zr 0 · 5 O 2 (HZO) thin film synthesized through the atomic layer deposition (ALD) method is used as a photocatalyst for the rhodamine B (RhB) dye decomposition under visible light irradiation. The photocatalytic RhB dye decomposition performances with or without an external magnetic field excitation provided by a commercial NdFeB magnet are experimentally characterized. With the increasing of the external direct-current (DC) magnetic field from 0 to 3000 Gs, the photocatalytic RhB dye decomposition ratio by HZO film obviously increases from 87.20 % to 98.17 %, which is attributed to the enhanced separation of the photo-induced positive and negative carrier due to the magnetic Lorentz effect. The magnetically-induced enhancement of photocatalysis in the ferroelectric HZO film, provides a method with these advantages of simple external excitation method, remarkable promotion effect and friendly-environment to enhance the dye decomposition ratio, and is potential in the practical application of photocatalytic dye wastewater treatment through harvesting the clean solar energy in future. [ABSTRACT FROM AUTHOR]

AbstractDye-sensitized solar cells offer a promising alternative to conventional photovoltaics due to their low production costs and high power conversion efficiencies. A crucial component in DSSCs is the counter electrode, which facilitates the redox reaction by collecting electrons and catalyzing the reduction of oxidized species in the electrolyte. The performance of DSSCs heavily depends on the CE material. Platinum, both in bulk and nanomaterial forms, is commonly used due to its excellent catalytic activity and conductivity, though its high cost drives the search for alternatives. Carbon-based materials, such as graphene and graphene sheets, are cost-effective substitutes, offering high electrical conductivity, large surface area, and mechanical strength. Methods like chemical vapor deposition, thermal exfoliation, and chemical reduction are used to synthesize graphene-based CEs. Polymer-based materials, including conducting polymers like poly(3,4-ethylenedioxythiophene) (PEDOT) and polyaniline (PANI), present another attractive option. These polymers are synthesized through in-situ polymerization, electrochemical deposition, and chemical vapor deposition, providing flexibility and tunability. Advancements in novel materials and synthesis methods for CEs continue to enhance DSSC efficiency and reduce costs, promoting their potential for large-scale renewable energy applications. [ABSTRACT FROM AUTHOR]

The sluggish kinetics of BiVO4 limits its applications in solar-to-hydrogen energy conversion. In this work, the zeolitic imidazolate framework ZIF-67 as a cocatalyst was immobilized on a BiVO4 nanocone via a solution-based photo-deposition method for photoelectrochemical water oxidation. Under the assistance of the nano-tip effect induced by the BiVO4 tip, nanoflower-like ZIF-67 was selectively grown at the vertex of the BiVO4 nanocone. The constructed BiVO4/ZIF-67 composite photoelectrode yielded a photocurrent of 0.92 mA cm−2 at ∼1.23 VRHE, which is about 3.5-fold that of pure BiVO4. In addition, surface/bulk charge separation efficiencies (ηsurf and ηbulk) were elevated when compared to those of the BiVO4 photoelectrode. Photoelectrochemical impedance spectroscopy (PEIS) and intensity modulated photocurrent spectroscopy (IMPS) measurements were further investigated to reveal the critical role of the modification of ZIF-67 in suppressing charge recombination and improving the photoelectrochemical activity of BiVO4. This research presents a feasible way to design a BiVO4/MOF composite photoanode induced by the nano-tip effect for enhanced photoelectrochemical water splitting performance. [ABSTRACT FROM AUTHOR]

Overall urea–water electrolysis has the potential to be employed in the purification of urea-containing wastewater and the production of hydrogen. However, the lack of cost-effective catalysts currently presents a significant obstacle to the further development of this technology. Through a simple template-directed selenium reaction in a novel type of highly active solution, an interface engineering strategy was designed to synthesize hollow CuSe nanocubes as an efficient bifunctional catalyst. The unique hollow CuSe nanocubes exhibit significant catalytic efficiency because of their larger electrolyte contact area and faster ion transport. In 1 M KOH with a 0.5 M urea electrolyte, CuSe/NF required an overpotential of 199 mV for HER and a potential of 1.38 V for UOR to achieve a current density of 10 mA cm−2. It can work stably for 24 h without significant degradation of activity at 10 mA cm−2, showing excellent durability and excellent stability. For overall urea–water electrolysis, it exhibits a remarkable activity with a low cell voltage of 1.61 V at 10 mA cm−2. Consequently, the design strategy of this unique hollow-structured CuSe provides a new insight to improve electrocatalytic performance and stability. [ABSTRACT FROM AUTHOR]

The employment of catalysts to split water to create hydrogen is viewed as an effective solution to the energy crisis problem. In this work, type II heterojunction CdIn2S4/g-C3N4 nanocomposites with different mass ratios were successfully synthesised using a simple sonication technique. The results show that the constructed CdIn2S4/g-C3N4 heterojunctions exhibit better catalytic performance in the photoelectrocatalytic water splitting reaction, and the photocurrent density of the composite with a composite ratio of 15% reaches 0.35 mA cm−2 at 1.23 V (vs. RHE), which is a 2.33-fold enhancement relative to g-C3N4. The constructed heterojunction facilitates the photogenerated charge transfer between CdIn2S4 and g-C3N4, effectively accelerating the separation of photogenerated electrons and holes. This work provides theoretical guidance for efficient PEC water splitting technology. [ABSTRACT FROM AUTHOR]