Application In Dye-sensitized Solar Cells Research Articles

Designing Efficient Metal-Free Dye-Sensitized Solar Cells: A Detailed Computational Study.

The modulation of molecular characteristics in metal-free organic dyes holds significant importance in dye-sensitized solar cells (DSSCs). The D-π-A molecular design, based on the furan moiety (π) in the conjugated spacer between the arylamine (D) and the 2-cyanoacrylic acid (A), was developed and theoretically evaluated for its potential application in DSSCs. Utilizing linear response time-dependent density functional theory (TDDFT) with the CAM-B3LYP functional, different donor and acceptor groups were characterized in terms of the electronic absorption properties of these dyes. All the studied dye sensitizers demonstrate the ability to inject electrons into the semiconductor's conduction band (TiO2) and undergo regeneration through the redox potential triiodide/iodide (I3-/I-) electrode. TDDFT results indicate that the dyes with CSSH anchoring groups exhibit improved optoelectronic properties compared to other dyes. Further, the photophysical properties of all dyes absorbed on a Ti(OH)4 model were explored and reported. The observed results indicate that bidentate chemisorption occurs between dyes and TiO4H5. Furthermore, the HOMO-LUMO energy gaps for almost all dye complexes are significantly smaller than those of the free dyes. This decrease of the HOMO-LUMO energy gaps in the dye complexes facilitates electron excitation, and thus more photons can be adsorbed, guaranteeing larger values of efficiency and short-circuit current density.

A novel Pt-free counter electrode based on MoSe2 for cost effective dye-sensitized solar cells (DSSCs): Effect of Ni doping

In this study, we propose a new counter electrode based on the Ni-doped MoSe2 as a viable counter electrode for DSSC applications. We investigate different ratios of Ni dopant inside the MoSe2 lattice. Our results show that the introduction Ni can increase the active surface area and improve the electrocatalytic behavior of the MoSe2 materials. We employed our prepared materials as the counter electrode in DSSCs and show that our optimized case demonstrates an open circuit voltage of 688 mV, a short circuit current density of 16 mA/cm2, a fill factor of 63% resulting an efficiency of 6.94% which is a significant improvement from the 6.68% efficiency of the DSSCs fabricated from the high-cost platinum counter electrode.

Ni1-xFexMnO3 perovskite photoanodes for dye-sensitized solar cells (DSSCs)

Dye-Sensitized Solar Cells (DSSCs) are a sustainable way to meet the upsurge in the global energy demands substituting the burning of the fossil fuels. Ni1-xFexMnO3 (x = 0, 0.2, 0.5, 0.8, 1.0) perovskite nanoparticles have been synthesized and proposed as promising photoanodes in DSSCs in this study. The impressive optical properties of the synthesized perovskites and the surface morphologies of the perovskite thin films suggest their suitability as photoanodes for DSSC application. The power conversion efficiency (PCE) of the iron incorporated NiMnO3 photoanodes based DSSCs increases compared to that of the pristine NiMnO3 based DSSC. Ni0.2Fe0.8MnO3 based DSSC displays the highest PCE of 0.79% with high open-circuit voltage (VOC) of 0.95 V. The results indicate that the perovskite composition with 20% Ni and 80% Fe in the A-site is the optimal stoichiometry required for reaping the maximum efficacy with reduced charge transfer resistance among the materials proposed in this study. This is attributed to the synchronized alignment of the conduction band edge with the lowest unoccupied molecular orbital (LUMO) of N3 dye sensitizer. It is worth noting that FeMnO3 based DSSC reaps the highest VOC of 1.02 V. The findings pave way for unconventional perovskite type materials to be applied as promising photoanodes for DSSCs yielding elevated VOC and PCE.

Role of cations in the photovoltaic performance optimization of ternary stannates, MSnO3 (M = Ca, Sr, and Ba) and N2SnO4 (N = Ca, Sr, Ba, and Zn)

Given the tremendous interest in next-generation photoelectric conversion devices, such as tandem solar cells, indoor photoelectric conversion devices, and image sensors, the development of device-specific electron transport materials is essential for achieving high performance. Sn-based semiconductors are one of the edge materials with the potential to satisfy these requirements. In particular, ternary stannate compounds have shown high potential as electron transport electrodes in several impressive studies. However, systematic research on the electronic band structure and chemical bonding characteristics of these materials remains insufficient. In this study, we present the effect of cations on the crystal structure and electronic band structure of ternary stannate compounds, MSnO3 (MSO, M = Ca, Sr, and Ba) and N2SnO4 (N2SO, N = Ca, Sr, Ba, and Zn). Additionally, their potential as electron transport electrodes is verified by application in dye-sensitized solar cells (DSCs). Notably, although BaSnO3 (BSO) and Zn2SnO4 (Z2SO) had inferior dye adsorption properties, they exhibited higher overall performance in DSCs than the other stannate compounds. The origin of the excellent performances of BSO and Z2SO is attributed to their supportive electronic band features, including the lower flat-band potential and conduction band than that of the lowest unoccupied molecular orbital level of N719 dye and excellent charge transport property. This study highlights the decisive impact of the electronic band structure and charge transport ability of stannate compounds on the photoelectric conversion performance and provides design guidelines for developing new charge transport materials.

Impact of Molecular Orientation on Lateral and Interfacial Electron Transfer at Oxide Interfaces.

Molecular dyes, called sensitizers, with a cis-[Ru(LL)(dcb)(NCS)2] structure, where dcb is 4,4'-(CO2H)2-2,2'-bipyridine and LL is dcb or a different diimine ligand, are among the most optimal for application in dye-sensitized solar cells (DSSCs). Herein, a series of five sensitizers, three bearing two dcb ligands and two bearing one dcb ligand, were anchored to mesoporous thin films of conducting tin-doped indium oxide (ITO) or semiconducting TiO2 nanocrystallites. The number of dcb ligands impacts the surface orientation of the sensitizer; density functional theory (DFT) calculations revealed an ∼1.6 Å smaller distance between the oxide surface and the Ru metal center for sensitizers with two dcb ligands. Interfacial electron transfer kinetics from the oxide material to the oxidized sensitizer were measured as a function of the thermodynamic driving force. Analysis of the kinetic data with Marcus-Gerischer theory indicated that the electron coupling matrix element, Hab, was sensitive to distance and ranged from Hab = 0.23 to 0.70 cm-1, indicative of nonadiabatic electron transfer. The reorganization energies, λ, were also sensitive to the sensitizer location within the electric double layer and were smaller, with one exception, for sensitizers bearing two dcb ligands λ = 0.40-0.55 eV relative to those with one λ = 0.63-0.66 eV, in agreement with dielectric continuum theory. Electron transfer from the oxide to the photoexcited sensitizer was observed when the diimine ligand was more easily reduced than the dcb ligand. Lateral self-exchange "hole hopping" electron transfer between surface-anchored sensitizers was found to be absent for sensitizers with two dcb ligands, while those with only one were found to hop with rates similar to those previously reported in the literature, khh = 47-89 μs-1. Collectively, the kinetic data and analysis reveal that interfacial kinetics are highly sensitive to the surface orientation and sensitizers bearing two dcb ligands are most optimal for practical applications of DSSCs.

Design a New D-π-A Formation Dyes as Dye-sensitized Solar Cells Applications/ a DFT and TD-DFT Study.

Dye-sensitized solar cells (DSSCs) have garnered significant interest among researchers in the field of photovoltaics due to their promising performance, low cost and easy process of fabrication. In this study, we have designed new D-π-A systems as derivatives of the reference (Ref. A) D-A-D scaffold, incorporating different π-bridges to enhance and optimize their efficiency as sensitizing dyes for DSSCs applications. Density functional theory (DFT) and time-dependent DFT (TD-DFT) methods were employed to investigate the geometrical and electronic structures, chemical reactivity indices, optical properties, exciton binding energy, and electrochemical properties of these dyes. We also examined the preferred adsorption process of the two selected dyes on a (TiO2)15 cluster model. The results demonstrate that all the dyes exhibit improved open-circuit photovoltage, enhanced light-harvesting efficiencies, higher electron injection efficiency, and excellent photovoltaic efficiency. Moreover, there is evidence of electron injection occurring from each studied dye to the conduction band of TiO2, followed by efficient regeneration. The introduced bridges in the molecular systems play a crucial role in facilitating electron transfer from the donor to the acceptor region. Comparatively, the D-π-D systems exhibit superior performance in DSSCs compared to Ref. A, which can be attributed to their higher energy levels of the lowest unoccupied molecular orbital and larger oscillator strengths for the most excited states involving intramolecular electron transfer and the electron injection process occurring from each examined molecule to the conduction band of TiO2, followed by subsequent regeneration. Overall, the results of our study highlight the potential of all the D-π-A systems as promising sensitizers for DSSCs applications, owing to their favorable optical and electronic properties and impressive photovoltaic parameters.

Synergistic co-sensitization of environment-friendly chlorophyll and anthocyanin-based natural dye-sensitized solar cells: An effective approach towards enhanced efficiency and stability

This study reports on the preparation of TiO2 nanorods (TNRs) and their application in dye-sensitized solar cells (DSSCs) to enable the production of efficient sources of energy for use in ambient indoor circumstances. The aim of the study is to enhance the efficiency and stability of DSSCs while also making them more affordable and eco-friendly. To achieve this, a novel approach was taken through the synergistic co-sensitization of environment-friendly natural dyes based on Spinacia Oleracea Leaves (SOL: chlorophyll) and Ixora Coccinea Flowers (ICF: anthocyanin). The combination of these dyes improved light absorption and charge separation, leading to enhanced power conversion efficiency. Various physicochemical characterizations of TNRs and dyes were performed and the co-sensitized dyes exhibited greatly enhanced visible-light photo-electrochemical performance which were later evaluated by J-V and electrochemical impedance spectroscopy (EIS) studies. Additionally, the role of various economical and environment-friendly counter electrodes was investigated. Using this co-sensitization technique, FTO/c-TiO2/TNRs/dyes/electrolyte/(C, Ninp, Nip) structured DSSCs were designed for the production of power under ambient light conditions. The optimal PCE of 2.39% is achieved under the artificial irradiation of ∼ 996 Wm−2 which is 2.3 and 4.2- times greater efficiency compared to single natural SOL and ICF-dyes-based DSSCs, respectively. Moreover, the synergistically co-sensitized DSSCs showed improved stability under prolonged light soaking (∼450 h) and storage conditions (at 27 °C). This study highlights the potential of PV technologies in enabling buildings and movable gadgets to become more independent and smarter while also providing an efficient source of energy for use in ambient indoor circumstances.

Fluorine-Doped Tin Oxide Thin Films with High Surface Conductance and Low Transparency for Boosting Performance in Dye-Sensitized Solar Cell Applications

Transparent conductive oxide films, like fluorine-doped tin oxide (FTO), are needed for electrochemical devices. FTO films are attractive due to their cost-effectiveness and high-temperature tolerance. Generally, solar cell fabrication requires high transmittance and low-conductivity FTOs. However, achieving both simultaneously poses a fundamental challenge. This study investigates the impact of FTO layer thickness, sheet resistance, transparency, and film morphology on optimizing the performance of dye-sensitized solar cells. To achieve this, a precursor solution containing SnCl4·5H2O and NH4F in isopropanol is sprayed onto a soda-lime glass substrate at 500 °C to form FTO films. The film thickness is varied by repeating the spray cycles. By increasing the number of spray cycles, the sheet resistance of the FTO film improves to ∼1.20 Ω □–1 with the expense of transmittance. The achieved very low sheet resistance of ∼1 Ω □–1 (∼3.54 × 10–4) Ω cm resistivity for the FTO film confirms the promise of this sequential spray pyrolysis technique in preparing highly conductive inert electrodes for various applications. Furthermore, DSCs with low transparency and sheet resistance showed higher-energy conversion efficiencies, challenging the current prerequisite of the requirement of high transmittance. The best efficiency (5.14%) is achieved with FTO films having a 34.2% transmittance and a 3.27 Ω □–1 sheet resistance, outperforming standard FTO films (4.74%) with a 10 Ω □–1 sheet resistance and an ∼83% transmittance. The results indicate that the transparency of FTO is not a dominant factor and carefully controlled light scattering and electrical properties in translucent FTO films would lead to the realization of dye-sensitized solar cells that deliver superior efficiency.

Enhancement of sensitization and electron transfer by kumkum dye in dye-sensitized solar cell applications

An anatase-based nanostructured TiO2 thin film paint was sprayed on FTO conducting glass to create dye-sensitized solar cells. Turmeric (Curcuma longa) and CaCO3 were used as natural sensitizers (DSSCs). FTIR and UV-Vis spectrophotometry was used to analyze the functional groups and optical characteristics of the dyes at absorbing photon energy of the semiconductor thin films, respectively. Both the XRD and UV results show that TiO2 has an anatase phase structure that is consistent with its broadband gap nature. The PL spectra of natural dyes were examined to determine their optical properties and the intensity of PL emission reported a bandgap of 4.72 eV and 4.95 eV respectively. The efficiency of the DSSC using Kumkum dye in ethanol is 0.9%, whereas in DI is 0.2%. Curcumin is a flavonoid polyphenol which is a very effective light-harvesting derivative required for the creation of charge carriers and generation of electric current has been found to be present in turmeric extract and is subjected to the coloring of natural sensitizers which enhance the absorption coefficient. Data Availability StatementThe datasets generated during and/or analyzed during the current study are available from the corresponding author upon reasonable request.

Green synthesis of TiO2 nanoparticles: dye-sensitized solar cells (DSSC) Applications : a review

Abstrak
 Peneltian ini bertujuan untuk mempelajaran teknik green synthesis nanopartikel, terkhusus untuk nanopartikel TiO2. Berbagai jenis tenaman bisa digunakan sebagai sumber senyawa ekstraksi (chaping agent, dan deionisasi logam Ti) pada proses sintesis nanopartikel TiO2; diantaranya: daun krokot (Portulaca Oleracea L.), Pisonia grandis (Leechai kottai keerai), jagung (zea mays), Kesumba Keling (bixa orellana), Biji kesumba (Bixa orellana seed), Jeruk (Citrus Limetta), Klabet (Trigonella foenum-graecum), Daun Kelor (Moringa Oleifera Leaf), dan Turi (Sesbania grandiflora). Nanopartikel TiO2 dapat diaplikasi sebagai dye-sensitized solar cells (DSSC). Ukuran nanopartikel TiO2 yang disintesis dengan precursor TPID dan memanfaatkan berbagai ektraksi tanaman telah menghasilkan ukuran 20-100 nm (spherical-like), dan ukuran kristal 9-13 nm (tetragonal crystalline). Sifat dasar dari nanopartikel TiO2 dijelaskna dengan baik (struktur krisal, gugus fungsi dan ukuran artikel), selanjutkan sifat, struktur, dan mekanisme transportasi muatan DSSC- juga dijelaskan dengan rinci. Bagian yang penting pada striuktur DSSC berbasis TiO2 nanopartikel ini adalah fotoanoda, katalis dan elektrolit. DSSC dengan fotoanoda TiO2 nanopartikel memiliki beberapa keunggulan, antara lain: efisiensi tinggi, biaya rendah, kestabilan tinggi, kinerja di bawah cahaya rendah, dan fleksibilitas desain. Hingga pengetahuan saya saat ini, efisiensi DSSC dengan bahan TiO2 telah mencapai lebih dari 14% dalam kondisi laboratorium. Namun, penting untuk dicatat bahwa efisiensi yang dapat diperoleh dalam praktik nyata dapat bervariasi dan masih ada tantangan dalam meningkatkan efisiensi tersebut. Pengembangan dan penelitian terus dilakukan untuk meningkatkan efisiensi DSSC dengan bahan TiO2 serta memperbaiki stabilitas dan biaya produksinya. Demikian halnya untuk DSSC dengan material TiO2-GO; memiliki kinerja tinggi dan sensitivitas yang baik, tetapi DSSC dengan TiO2 nanopartikel lebih teruji dan stabil dalam jangka panjang.
 Kata Kunci: Green synthesis, Dye-Sensitize solar cells, fotoanoda, Nanopartikel TiO2
 Abstract
 This research aims to study the technique of green synthesis of nanoparticles, especially for TiO2 nanoparticles. Various types of plants can be used as a source of extraction compounds (camping agents, and deionization of Ti metal) in the synthesis of TiO2 nanoparticles, including purslane leaves (Portulaca Oleracea L.), Pisonia grandis (Leechai kottai keerai), corn (Zea mays), Kesumba Keling (bixa orellana), Kesumba seeds (Bixa orellana seed), Oranges (Citrus Limetta), Clabet (Trigonella foenum -graecum), Moringa Leaves (Moringa Oleifera L.), and Turi (Sesbania grandiflora). TiO2 nanoparticles can be applied as dye-sensitized solar cells (DSSC). The size of TiO2 nanoparticles synthesized with TPID precursors and utilizing various plant extractions has resulted in sizes of 20-100 nm (spherical-like) and crystalline sizes of 9-13 nm (tetragonal crystalline). The basic properties of TiO2 nanoparticles are well described (crystal structure, functional groups, and particle size), while the properties, structures, and charge transport mechanisms of DSSC are also described in detail. The essential parts of the DSSC structure based on TiO2 nanoparticles are the photoanode, catalyst, and electrolyte. DSSC with TiO2 nanoparticle photoanode has several advantages, including high efficiency, low cost, high stability, performance under low light, and design flexibility. The efficiency of DSSCs with TiO2 materials has reached over 14% under laboratory conditions. However, it is essential to note that the efficiencies obtained in actual practice may vary, and there are still challenges in increasing these efficiencies. Development and research continue to improve the efficiency of DSSC with TiO2 materials and the stability and production costs. Furthermore, DSSC with TiO2-GO material; has high performance and sound sensitivity, but DSSC with TiO2 nanoparticles is more tested and stable in the long term.
 Keywords: Green synthesis, Dye-Sensitize solar cells, photoanoda, TiO2 Nanoparticles

Different Roles between PEDOT:PSS as Counter Electrode and PEDOT:Carrageenan as Electrolyte in Dye-Sensitized Solar Cell Applications: A Systematic Literature Review.

Poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) has been mostly used as a counter electrode to give a high performance of dye-sensitized solar cell (DSSC). Recently, PEDOT doped by carrageenan, namely PEDOT:Carrageenan, was introduced as a new material to be applied on DSSC as an electrolyte. PEDOT:Carrageenan has a similar synthesis process as PEDOT:PSS, owing to their similar ester sulphate (-SO3H) groups in both PSS and carrageenan. This review provides an overview of the different roles between PEDOT:PSS as a counter electrode and PEDOT:Carrageenan as an electrolyte for DSSC applications. The synthesis process and characteristics of PEDOT:PSS and PEDOT:Carrageenan were also described in this review. In conclusion, we found that the primary role of PEDOT:PSS as a counter electrode is to transfer electrons back to cell and accelerate redox reaction with its superior electrical conductivity and high electrocatalytic activity. PEDOT:Carrageenan as an electrolyte has not shown the main role for regenerating the dye sensitized at the oxidized state, probably due to its low ionic conductivity. Therefore, PEDOT:Carrageenan still obtained a low performance of DSSC. Additionally, the future perspective and challenges of using PEDOT:Carrageenan as both electrolyte and counter electrode are described in detail.

A computational approach for screening carbazole based organic dyes as potential photosensitizers for DSSCs application

The scientific community has shown significant interest in organic materials due to their potential applications in optoelectronics. In this study, we present the design and theoretical investigation of a new class of carbazole-based organic chromogens (R1-6). These chromogens consist of a heteroaromatic carbazole unit as an electron-rich donor, connected to a substituted phenyl ring carrying various electron acceptor groups. Specifically, we analyse the structural impact of electron withdrawing moieties such as carboxylic acid (–COOH), cyano (–CN), and nitro (–NO2) on the photophysical properties of these chromogens. To gain insights into the electron density localization and charge transfer characteristics, we perform DFT, TD-DFT, and MESP calculations. The computational studies indicate that these materials exhibit promising potential as sensitizers for applications in dye-sensitized solar cells (DSSCs).

Conductive Glass with Simple Spray Deposition Method for Dye-Sensitized Solar Cell Application

Dye-sensitized solar cells utilize a transparent conductive oxide (TCO) glass which is mainly Fluorine-doped tin oxide (FTO) for the working electrode and counter electrode. The TCO is one of the important parts of DSSC. TCO glass becomes the part that determines the price of mass production of DSSC. Low-cost TCOs with high conductivity and high light transmittance are required. In this study, We proposed a simple fabrication of TCO glass by spray deposition method of Tin (II) Chloride (SnCl2) on top of the lime glass substrate. Fabrication was started with 3 mm of Lime glass cleaned with distilled water and ethanol in sonication for 15 minutes and 10 minutes heating at 500°C. The variation of layer thickness was performed by multilayer spray using 2 mg SnCl2 and 5 ml ethanol mixture and then baked for 10 minutes at 500°C. The electrical conductivity, light transmittance, and roughness of the glass at one spray layer were 20 Ω/cm2, 87.1 %, and 0.010 µm respectively, and decrease along with the increase of the number of spray layers. A multimeter, UV-VIS Spectrophotometer, and 3D Measuring Laser Microscope are used to measure these parameters in this study. Compared to the properties of commercially available Fluorine doped Tin Oxide (FTO) glass, this method can be used as an alternative for conductive glass production for Dye-Sensitized Solar cells.

The Addition of C, Zn-C and Sn-C on Anatase Titanium Dioxide (TiO2) for Dye-Sensitized Solar Cells Application

DSSC (dye-sensitized solar cell) is a third-generation photovoltaic technology that can convert solar energy into electric current using a photoelectrochemical mechanism. Photoelectrode is one of the significant elements in DSSC, where photoexcited electrons are generated, and serves as an electron transport medium. Anatase titanium dioxide (TiO2) is often used as photoelectrode material because of its excellent photoactivity, high stability, non-toxicity, environmental friendliness, and low price. Many DSSC modifications have been conducted to overcome the efficiency limitations in DSSC, and one of them is carried out by modifying the TiO2 via doping. In this study, TiO2 doped with C and co-doping with Zn (Zn-C) and Sn (Sn-C) were prepared using sol-gel reactions, and they were subsequently applied and tested as photoelectrode in DSSC. The results showed that undoped and doped TiO2 had a porous spherical morphology with inhomogeneous particle sizes. The addition of C, Zn-C and Sn-C dopants has reduced in the crystallite size and the band gap energy of TiO2. The efficiency of DSSC with undoped TiO2 DSSC was 3.83%, while the best performance was obtained from DSSC C-TiO2 with an efficiency of 4.20%. In contrast, the DSSC with Zn-C-TiO2 and Sn-C-TiO2 co-doping produced unexpectedly lower efficiency of 0.71% and 0.85%, respectively.

Thorn-like morphology of TiO2 hierarchical structures for efficient dye-sensitized solar cell application

The efficiency of Dye-sensitized solar cells (DSSCs) can be improved through the employment of one-dimensional TiO2 nanostructured thin film photoanode materials. Herein, we have synthesized a 1D thorn-like nanostructure by the hydrothermal method as a photoanode in the DSSCs. The influence of the reaction time on the morphological, structural, and optical properties of the TiO2 nanostructures was studied. Field emission scanning electron microscopy (FE-SEM) showed the formation of nanothorn - like structures with an average length of 12 µm in 12 h reaction time, whereas a growth time of 18 h, micro flower-like structures were obtained. The dye-sensitized solar cell was fabricated with the two different prepared morphologies and the efficiency was found to be 0.51% and 1.2% for TiO2 samples prepared at 12 and 18 h.

Correction: Benzoxanthones derivatives: insight into oxalic acid catalyzed synthesis, crystallographic analysis and potential application in dye-sensitized solar cell

Correction: Benzoxanthones derivatives: insight into oxalic acid catalyzed synthesis, crystallographic analysis and potential application in dye-sensitized solar cell

Synthesis of new benzimidazole based ruthenium (II) dyes for application in dye-sensitized solar cells with detailed spectroscopic and theoretical evaluation

In this work, four ancillary ligands named SL-1 to SL-4, having core nucleus of 2-(2-pyridyl) benzimidazole, augmented with electron donating and electron withdrawing groups were successfully synthesized in good yields. The characterization of ligands was assured by FTIR, 1HNMR, 13CNMR, and X-ray crystallographic analysis. The as-synthesized ligands were subjected to complexation with 2,2′-bipyridyl-4,4′-dicarboxylic acid and potassium thiocyanate to prepare four new ruthenium (II) dyes. All the synthesized ruthenium (II) dyes were characterized by infrared spectroscopy and their photophysical and electrochemical studies were compared to the benchmarked dye (N719). Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) were performed to gain deep insights and better understanding of the quantitative structure-property relationships of the named ruthenium dyes (SL1–4). Results showed excellent correlation between the experimental and theoretical results; all the four new dyes exhibited narrow band gap and low singlet excitation energies (1.33 – 1.72 eV) indicating good light harvesting ability in DSSCs. Mulliken charge analysis reveals the intramolecular charge transfer between the highly electronegative nitrogen and oxygen donor centers and the strongly electropositive ruthenium acceptor in the synthesized dyes.

Hydrothermal duration effect on the self-assembled TiO2 photo-anode for DSSC application

Dye-sensitized solar cell (DSSC) has been extensively researched over the past few decades due to its facile and low-cost fabrication process compared to the silicon solar cell. Generally, the photo-anode of the DSSC consists of a titanium dioxide (TiO2) film deposited on a transparent conducting oxide (TCO) substrate. Hydrothermal method is the most widely adopted technique for the synthesis of TiO2 photo-anode. Nevertheless, the optimum hydrothermal synthesis parameters have yet to be elucidated. In this work, the influences of hydrothermal duration on the self-assembled TiO2 photo-anode were investigated. It was discovered that the rutile content in the TiO2 photo-anodes can be controlled by adjusting the hydrothermal durations. The highest DSSC efficiency of 3.88% was achieved at an optimum hydrothermal duration of 10 h, corresponding to a rutile content of 80.43%. The improvement in DSSC efficiency can be ascribed to the reduced electron-hole recombination resulting from electron transfer from rutile to anatase lattice trapping sites, thereby improving the photocurrent. However, when the hydrothermal durations exceeded 10 h, the DSSC efficiency dropped due to the agglomeration of the rutile TiO2 resulted from excessive rutile content, which led to decreased surface area for dye adsorption and hence lower photocurrent. The results suggest the importance of controlling the hydrothermal duration on the synthesis of TiO2 photo-anode.

Green synthesis of ZnO nanoparticles using marine brown algae (Cystoseira) extract comprising sol–gel, and combustion techniques based on dye-sensitized solar cells application

The ZnO nanoparticles were synthesized using marine brown algae (Cystoseira) extract and calcination. For comparison, combustion, and sol–gel methods were employed to synthesize nanoparticles to use as material in dye-sensitized solar cells (DSSCs) photoanode. The produced nanoparticles were characterized using structural and morphological studies by FTIR, SEM, and XRD experiments, respectively. The results revealed that the net hexagonal crystal structure was achieved with a crystal size of less than 100 nm, good purity, spherical shape, and a suitable dimension for fabricating DSSCs. They exhibit enhanced properties due to the variation in their characteristics such as average size, size distribution, and morphology. The ZnO nanoparticles were used to fabricate the DSSCs by the doctor blade method, and the efficacy of each cell was evaluated using voltage–current measurement. The results were in good agreement with the characteristic curve of the commercialized DSSC. The best performance for the fabricated DSSCs was achieved using green synthesized ZnO nanoparticles, because of the influence of their morphology such as smaller crystal size, more grain boundaries, and bigger surface area. The cell’s solar-to-electricity conversion efficiency, short-circuit current, open-circuit voltage, and fill factor were measured as ∼1.13%, 3.8[Formula: see text]mA/cm2, 620[Formula: see text]mV, and 54.3%, respectively. The enhanced photovoltaic properties were ascribed to the flower-like morphological structures of the ZnO nanoparticles prepared using the green synthesis method.

The effect of central transition metals and electron-donating substituent on the performances of dye/TiO2 interface for dye-sensitized solar cells applications

Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) approaches were applied to explore the effect of central transition metals and the dye/TiO2 interface on dye-sensitized solar cell (DSSC) performance and supply a promising way to estimate and screen possible candidates for DSSC applications. The interaction properties, bonding characteristics, sensitized mechanisms, charge transfer, frontier molecular orbitals, energy gap, partial densities of states (PDOS), non-covalent interactions (NCI), and electronic absorption spectra were examined and analyzed to provide the photovoltaic characteristics of Sc, Cu, and Ti tetrasulfonic acid phthalocyanine sensitizer@TiO2 interface in both gas phase and polar solvent as acetonitrile.The interfacial of TiPc-(SO3H)4 with TiO2, which facilitates the driving force for the electron injection of photosensitizers (ΔGinj), increases the charge separation, open-circuit voltage (Voc), and high light-harvesting efficiency (LHE) values. However, minimize the charge recombination, lifetime of the excited state (τ), regeneration driving force (ΔGreg). Our results reveal that TiPc-(SO3H)4@TiO2 is superior to those of ScPc-(SO3H)4, CuPc-(SO3H)4, TiPc-(SO3H)4 and Pc-(SO3H)4/TiO2, indicating the novel TiPc-(SO3H)4@TiO2 interface could be promising candidates for DSSC photovoltaic devices performance. In addition, the static mean polarizability and first hyperpolarizability of all six dyes elucidated that the TiPc-(SO3H)4@TiO2 interface can be regarded as a potential performer in non-linear optical (NLO) properties. These theoretical identifications may provide novel perspectives and instructions for future experimental researchers to promote the synthesis and application of TiPc-(SO3H)4@TiO2 interfaces to improve the photo-to-current conversion efficiency.