Application In Dye-sensitized Solar Cells Research Articles

Molecular Design and DFT Analysis of High-performance Dyes Based on Pyrene with Different Donor Parts and Their Optoelectronic Applications.

The performance and efficacy of dyes, which are crucial photon-harvesting components in dye-sensitized solar cells (DSSCs), must be meticulously analysed at the molecular level. This research focuses on a theoretical investigation of dye characteristics rather than the synthesis of novel compounds. Using Density Functional Theory (DFT) and Time-Dependent DFT (TD-DFT), we have analysed six D-π-A structure dyes designed with pyrene as the π-bridge and various functional groups as donors. Our study examines their geometrical, electronic, optical, electronic localization, and electrochemical properties. The findings reveal that these theoretically designed D-π-A dyes show significant improvements in light-harvesting efficiency, open-circuit photovoltage, electron injection efficiency, and overall photovoltaic performance. The analysis indicates effective electron injection from each dye into the conduction band of TiO2, followed by efficient regeneration and enhanced intra- and intermolecular charge transfer properties. The incorporation of pyrene as a π-bridge and the use of different functional groups as donors are crucial for facilitating electron transfer from the donor to the acceptor region. Among the dyes studied, the D-π-D modified dye demonstrates superior theoretical performance, attributed to its higher energy levels of the lowest unoccupied molecular orbital and greater oscillator strengths for excited states. This results in improved intramolecular electron transfer and electron injection into the conduction band of TiO2, followed by effective regeneration. Overall, our study highlights the potential of these theoretically modeled dyes as highly promising sensitizers for DSSCs, due to their exceptional optical and electronic properties and impressive photovoltaic parameters. These findings position these molecular structures as strong candidates for future applications in organic DSSCs.

Optimal extraction, phytochemical and electrochemical potential assessment of pigments from Persicaria Lapathifolia for dye-sensitized solar cell application

In this study, we concentrated on optimal extraction, phytochemical, and electrochemical assessment of natural pigments from the roots and flowers of Persicaria lapathifolia as new sensitizers in dye-sensitized solar cells. The extraction technique required optimizing the use of acidified ethanol with acetic acid and hydrochloric acid as flower and root extractants, respectively. Photo-electrochemical tests revealed that these pigments could improve the efficiency of DSSCS. The optical characterization revealed maximal absorbance peaks at 462 and 654 nm for root dye and 535, 606 and 666 nm for blossom dye. Phytochemical examination revealed the presence of anthocyanins flavonoids glycoside linkage and betacyanin in both extracts. The Cyclic voltammetry tests revealed oxidation potential peaks in root and floral dyes the HOMO and LUMO potentials were calculated for both dyes, revealing values that could help improve DSSC performance. The DSSCS sensitized with flower extract had an open circuit voltage of 0.649 V a brief current pulse of 3.8 mA and an efficiency of 1.6335%. On the other hand root, pigment-based DSSCS performed slightly inferior with a Voc of 0.55 V an Isc of 3.7 mA, and an efficiency of 1.33%. These findings point to the potential of Persicaria lapathifolia pigments to boost DSSC efficiency emphasizing the relevance of sustainable energy sources. More research and optimization are required to realize the potential of these natural pigments for DSSC applications. This study adds to the investigation of green energy options, notably rooftop photovoltaic systems, in response to an increasing desire for ecologically sound energy solutions.

Novel Zinc-porphyrin dyes for dye-sensitized solar cells that enables light capture in the near-ultraviolet and visible range

Two novel Zinc-porphyrin central dyes (T-5 and T-6) containing acetylene moiety have been designed and synthesized for application in dye-sensitized solar cells (DSSCs). The light-harvesting capabilities and photovoltaic performance of these dyes were investigated systematically through comparison of different donor (D) unit. Devices fabricated from phenoxazine (POZ)-based molecule T-5 showed higher short-circuit current (JSC, 11.32mAcm-2) compared to T-6 which based on phenothiazine (PTZ) (10.1mAcm-2) under standard global AM 1.5G solar condition. This is due to the fact that the POZ unit has a greater electron supply capacity than the PTZ unit. The introduction of the acetylene moieties into the molecular structure broadens the light absorption range of the dye molecule to the entire visible range and the near-ultraviolet region. The conclusions of this paper demonstrate that incorporating strong electron donor groups in dye molecules, in synergy with conjugated groups, broadens the spectral range of light absorption, thereby enhancing the performance of the dye device.

Comparing Fluoro- and Trifluoromethyl functionalized Ni(II) 1,1-dithiolates with 1,1'-bis-(diphenylphosphino)ferrocene co-ligand in DSSC applications

Four new heteroleptic Ni(II)-dithiolates with general formula [Ni(dppf)(dithiolate)] (dithiolate = 2-cyano-2-(4-fluorophenyl)ethene-1,1-bis(dithiolate) (Ni-1); 2-cyano-2(2-(trifluoromethyl)phenyl)ethene-1,1-bis(thiolate) (Ni-2); 2-cyano-2(3-(trifluoromethyl)phenyl)ethene-1,1-bis(thiolate) (Ni-3) and 2-cyano-2(4-(trifluoromethyl)phenyl)ethene-1,1-bis(thiolate) (Ni-4); dppf = 1,1′-bis(diphenylphosphino) ferrocene) have been synthesized and characterized spectroscopically as well as by single crystal X-ray diffraction technique. Single crystal X-ray analyses for Ni-1 and Ni-2 reveal distorted square planar geometry around Ni(II) that are satisfied by two sulfur and two phosphorus centers of the dithiolate and dppf ligands, respectively. These complexes have been used as photosensitizers in TiO2-based dye-sensitized solar cells (DSSCs) which suggest that the performance of fluoro-substituted sensitizer Ni-1 is superior to that of the other three trifluoromethyl-substituted sensitizers. Ni-1 showcases an efficiency (η) of 5.47%, open circuit potential (Voc) of 0.699V, short circuit current (Jsc) of 12.17mA∙cm-2 and display 64% incident photon-to-current conversion efficiency. The plausible reason for the variation in photovoltaic performances have been explained by integrated experimental methods and theoretical calculations. Results indicate that the small sized fluoro-group exhibits significant p-orbital overlap with the aromatic fragment of the dithiolate ligand, allowing facile photo-induced electron transfer from sensitizer to titania, thereby enhancing the electron donation from dppf→Ni(II)→dithiolate. Further, the cell fabricated with Ni-1 retains approximately 93% of its initial conversion efficiency in 800h time span.

Designing and computational investigation of acceptor for dye-sensitized solar cell and nonlinear optical properties

Systematic strategies have been employed to designing the acceptor part for dye sensitized solar cell and nonlinear optical properties using density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations. The designed dyes have followed donor-π-spacer-acceptor (D-π-A) pattern. For designing of organic dyes, we have utilized the 7,7,8,8-tetracyanoquinodimethane (TCNQ) unit as a accepter for dye-sensitized solar cells (DSSCs) and investigating the impact of various electron acceptor in the designed framework. For designing of such framework, we have employed B3LYP level of theory and 6–311+G(d,p) basis set. Initially, the optoelectronic properties of the metal free dyes are calculated based on different acceptors and then we have designed (2–9) dyes. The designed dyes which contain TCNQ-based acceptors show enhance power conversion and optoelectronic properties than that of reference one. We have calculated different parameters such as dipole moments (μnormal), band gap (Egap), electron injection (ΔGinjection), driving force of regeneration (ΔGregen), and nonlinear optical (NLO) properties. We have also investigated the essential process of dye adsorption on titanium dioxide (TiO2) surfaces. The calculated values of μnormal (17.79 & 22.37 debye) and Egap (0.57 & 0.88 eV) for dyes 8 &9 respectively which are more efficient than that of dye 1. Furthermore, the calculations for density of state (DOS) and partial density of state (PDOS) validate the FMO analysis and demonstrate effective charge transfer from the HOMO to LUMO. Further, the designed dye molecules were exhibiting enhanced and gigantic nonlinear optical properties. In comparison to cyanoacrylic acid, the TCNQ group has the potential to function as a superior acceptor in upcoming applications of DSSCs.

Study of photosensitizer dyes for high-performance dye-sensitized solar cells application: A computational investigation

Dye-sensitized solar cells (DSSCs) offer a promising, cost-effective alternative to conventional photovoltaic systems. Organic sensitizers, capable of capturing a broad spectrum of sunlight, are key components in DSSCs, but their development and testing are often time-consuming and expensive. Quantum chemical calculations, specifically Density Functional Theory (DFT), have emerged as valuable tools to evaluate potential dye candidates, streamlining the design process and reducing costs. This study investigated the molecular structures and photophysical properties of three common dye classes used in high-performance DSSCs: natural pigments, anthocyanidin pigments, and squaraine dyes. Employing DFT and time-dependent DFT (TD-DFT) at the B3LYP/6–31G level, key parameters such as the HOMO-LUMO energy gap, free energy differences for electron injection and dye regeneration, short-circuit current density, total reorganization energy, and open-circuit voltage were analyzed. Additionally, maximum absorption wavelengths and oscillator strength values were calculated. Our findings provide valuable insights into the optical and electrical properties of these natural dyes, aiding DSSC manufacturers in selecting optimal sensitizers. This research highlights the potential of computational methods in accelerating dye development and improving the overall efficiency of DSSC technology.

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

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

Tio2 as the Economically Semi Conducting Layer for Dye-Sensitized Solar Cell (DSSC) Application

Tio2 as the Economically Semi Conducting Layer for Dye-Sensitized Solar Cell (DSSC) Application

Influence of Graphene on Sheet Resistivity and Urbach Enery of Nano TiO<sub>2</sub> for DSSC Electrode

Importance of renewable energy cannot be over emphasized. Titanium IV oxide (TiO<sub>2</sub>) is the most suitable semiconductor for dye sensitized solar cell (DSSC) due to its chemical stability, non toxicity and excellent optoelectronic properties. In this research TiO<sub>2</sub> is coated on graphene to enhance its charge transport aiming to reduce recombination which is a main set back in DSSCs. undestanding graphene- TiO<sub>2 </sub>contact is therefore essential for DSSC application. TiO<sub>2</sub> thin films were deposited on single layer graphene (SLG) as well as on flourine tin oxide (FTO) using doctor blading technique. The films were annealed at rates of 2°C /min and 1°C/min up to a temperature of 450°C followed by sintering at this temperature for 30 minutes. Four point probe SRM-232 was used to measure sheet resistance of the samples. The film thickness were obtained from transmittance using pointwise unconstrained minimization approximation (PUMA). UV –VIS spectrophotometer was employed to measure transmittance. Resistivity of TiO<sub>2</sub> on both FTO and Graphene were of order 10<sup>-4</sup> Ωcm. However, TiO<sub>2</sub> annealed on graphene matrix exhibited a slightly lower resistivity 5.6 x10<sup>-4</sup> Ωcm as compared to 6.0x10<sup>-4 </sup>Ωcm on FTO. Optical transmittance on visible region was lower for TiO<sub>2</sub> on FTO than on SLG, 71.48% and 80.11% respectively. Urbach energy (Eu) for weak absorption region decreased with annealing rate. Urbach energies for 1°C/min TiO<sub>2 </sub>on FTO and SLG were 361 meV and 261meV respectively. This was used to account for decrease of disoders of films due to annealing. A striking relation between sheet resistivity and urbach was reported suggesting SLG as a suitable candidate for photoanode of a DSSC.

Synthesis of MnO2/ZIF-8 for the construction of Pt-free counter electrode for dye-sensitized solar cell applications

Synthesis of MnO2/ZIF-8 for the construction of Pt-free counter electrode for dye-sensitized solar cell applications

Molecular Engineering Strategies of Spectral Matching and Structure Optimization for Efficient Metal-Free Organic Dyes in Dye-Sensitized Solar Cells: A Theoretical Study.

Metal-free organic dyes are promising dyes that can be applied widely in dye-sensitized solar cells (DSSCs). The rational design and selection of dyes with complementary absorption can promote the development of methods that can enhance the utilization of incident light by DSSCs, such as cosensitization and tandem devices. Based on these opinions, the structure of the reported high-performance metal-free organic dye ZL003 is used as a template to design two new metal-free organic dyes, HX-1 and HX-2, by replacing its donor unit with a 2-phenothiazine-phenylamine unit and fusing its three independent π-bridge units into a whole with the aim of driving the red shift and the blue shift of the absorption spectra of ZL003, respectively. Through theoretical investigation, it is demonstrated that the perfect complementary optical absorption of HX-1 and HX-2 can be realized as the shift of the absorption spectra of ZL003 to different directions, which means their feasibility to the application in cosensitization or tandem dye-sensitized solar cells (T-DSSCs). Furthermore, it is hypothesized that HX-1 may be the dye with better photovoltaic performance than ZL003 by modeling their intramolecular charge-transfer (ICT) processes, TiO2 surface adsorption, and photovoltaic parameters. The short-circuit current density (Jsc) and photoelectric conversion efficiency (PCE) of HX-1 are 23.10 mA·cm-2 and 21.26% in theory, compared to those of 20.68 mA·cm-2 and 19.64% in ZL003 at the same computational level, respectively. In view of the complementary optical properties, the combination of HX-1 with HX-2 may be a reasonable option for dyes for the development of a highly efficient cosensitization system or T-DSSCs in the future. In terms of such findings, these two novel metal-free organic dyes may have bright prospects in the research of highly efficient DSSCs, and this work can provide a reference for the design of dyes with complementary absorption through simple structural adjustments of the realistic dyes with high photovoltaic performance.

TiO2 nanoparticle seeds transformed into nanotubes for effective dye-sensitized solar cell application

Morphology plays a vital role in dye-sensitized solar cells (DSSCs) due to their high surface area, dye adsorption and electron transport. In this study, we have designed and fabricated titanate nanotube photoanodes by a simple one-step hydrothermal method. High-resolution transmission electron microscope (HRTEM) analysis revealed the transformation of nanoparticles to nanotube morphology. Brauner-Emmett-Teller (BET) method showed the enhanced surface area and pore diameter of nanotubes. TiO2 nanotube photoanode showed excellent energy conversion efficiency (2.38 %), short circuit current densities (Isc) (6.29 mA/cm2), and fill factors (FF) (0.63), respectively.

Design and fabrication of NiCo2S4@rGO as an efficient Pt free triiodide reducing agent for dye-sensitized solar cell application

Exploiting efficient Pt-free counter-electrode materials with low cost and highly catalytic property is a hot topic in the field of Dye-sensitized solar cells (DSCs). Here, NiCo2S4/reduced graphene oxide (RGO) was prepared via an economical hydrothermal ynthesis route, and the as-prepared composite exhibited comparable electrocatalytic property with the conventional Pt electrode as the counter-electrode. Enhanced optoelectronic, optical and structural characteristics have been attained over the constructed heterojunction. Band gap energy of NiCo2S4 (2.35 eV) was suppressed to 2.11 eV owing to its supporting with 10 wt.% rGO bringing about upgraded absorption of visible light. Electrochemical studies confirmed the synergetic effect of nickel and cobalt ions with the high electrical conductive rGO networks that enhance the electrocatalytic activity of NiCo2S4 nanostructures. The efficiency achieved for the NiCo2S4@rGO counter electrode (CE) based DSSC is 8.17%, which is remarkably higher than that of pristine NiCo2S4 (7.31%), and Pt (7.14%) under the same experimental conditions. In outline, given their innovative synthesis approach, affordability, and remarkable electrocatalytic attributes, the newly developed NiCo2S4@rGO counter electrodes stand out as potent contenders in future dye-sensitized solar cell applications.

Chemical structure modification of Brazilin-based natural dye with TiO2 nanostructure improves photovoltaic properties for maximum simulated PCE for DSSCs application

Brazilin has been explored as a photosensitizer in dye-sensitized solar cells (DSSCs) owing to its easy extraction, abundance, and environmental friendliness. However, its narrow solar spectrum absorption and weak interaction with the semiconductor hamper its wide application, highlighting the need for developing novel dyes for enhanced DSSC performance. This study reports eight designed dyes (Braz 01 ‒ Braz 02tb) obtained via introducing the π-bridges such as benzene, thiophene, and benzene-thiophene linked to thieno[3,2-b]thiophene, alongside a cyanoacrylic acceptor into the sites of two hydroxyl (OH) groups of brazilin dye. The density functional theory (DFT) and time-dependent density functional theory (TD- DFT) methods were employed to examine the free dyes' photoelectrical, optoelectronic and structural properties. The results show that the absorption spectra of the designed dyes redshifted by 183.22 nm 239.43 nm regarding the brazilin dye. The energy gap was reduced from 5.074 to 2.46 eV. The reorganization energy decreased from 0.951 eV to 0.528 eV, indicating that the designed dyes exhibited better intramolecular charge transfer (ICT). Notably, the electron affinity, electron accepting power, and maximum charge transfer increased from 1.021 3.472 eV, 1.024 8.387 eV and 1.447 4.780, respectively, signifying improved ICT. The exciton binding energy was lowered from 0.591 0.137 eV, implying that all designed dyes possess minimum charge recombination. The amount of charge transfer of the designed dyes (0.286219.051 au) was observed to be greater than brazilin, signifying enhanced ICT. Moreover, the theoretical DSSCs sensitized with designed dyes demonstrated higher PCE than brazilin dye. The greatest PCE of 13.1 % was attained by Braz 01tb dye. Generally, the improved optoelectronic and photovoltaic characteristics observed in all the designed dyes indicate that modifying the hydroxyl group on the brazilin's R1 or R2 location enhances its photoelectrical properties. Therefore, the designed dyes are regarded as superior candidates for utilization as photosensitizers in DSSCs.

Dye-sensitized solar cells based on anatase- and brookite-TiO2: enhancing performance through optimization of phase composition, morphology and device architecture

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 μms. 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.

Boosting the performance of dye-sensitized solar cells by employing Li-substituted NiO nanosheets as highly efficient electrocatalysts for reduction of triiodide

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 I3− ions. The cyclic voltammetry (CV) result of 5 mol% of Li substituted NiO (5-LNO) shows outstanding electrocatalytic activity towards the redox reaction of I3−/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 (Jsc) of 18.76 mAcm−2, and open-circuit voltage (Voc) of 0.80 V which is higher than Pt-based CE (η of 4.05 % with Jsc of 10.16 mAcm−2, and Voc 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.

Effect of nickel oxide concentration on titanium oxide bilayer photoanode for dye-sensitized solar cell application

The mesoporous titanium oxide has attracted significant attention as a photoanode material for Dye-Sensitized Solar Cells (DSSCs). In the present work, we coated a planar NiO layer on the TiO2 film to minimize charge recombination with the dye and/or electrolyte molecules. The structural, morphological, elemental, optical, and electrical properties of the TiO2 and bi-layered TiO2/NiO films were studied using various characterization techniques. DSSCs based on N3 dye-sensitized TiO2 and bi-layered TiO2/NiO films were fabricated using PI as the redox electrolyte. The photocurrent density–voltage (J–V) characteristics of the DSSCs were studied using a solar simulator. Various parameters, such as open-circuit voltage (Voc), short-circuit photocurrent density (Jsc), and fill factor (FF), were calculated from the J–V characteristics. DSSCs based on bi-layered TiO2/NiO films showed superior performance compared to bare TiO2 films. The J–V characteristics of bilayer film shows enhanced open-circuit voltage (Voc) ~ 0.56 V, short-circuit current density (Jsc) ~ 2.14 mA/cm2, fill factor (FF) ~ 75%, and efficiency (ƞ) ~ 0.91%. The TiO2/NiO solar cell showed a ~ 28% increase in efficiency compared to TiO2-based DSSC. Hence, the bi-layered TiO2/NiO films have potential applications in optoelectronic and photovoltaic devices.

Enhancing Efficiency of Dye Sensitized Solar Cells by Coinage Metal Doping of Cyanidin-Silver Trimer Hybrids at TiO2 Support Based on Theoretical Study.

Identification of a natural-based sensitizer with optimal stability and efficiency for dye-sensitized solar cell (DSSC) application remains a challenging task. Previously, we proposed a new class of sensitizers based on bio-nano hybrids. These systems composed of natural cyanidin dyes interacting with silver nanoclusters (NCs) have demonstrated enhanced opto-electronic and photovoltaic properties. In this study, we explore the doping of silver nanocluster within a cyanidin-Ag3 hybrid employing Density Functional Theory (DFT) and its time-dependent counterpart (TDDFT). Specifically, we investigate the influence of coinage metal atoms (Au and Cu) on the properties of the cyanidin-Ag3 system. Our findings suggest that cyanidin-Ag2Au and cyanidin-AgAuCu emerge as the most promising candidates for improved light harvesting efficiency, increased two-photon absorption, and strong coupling to the TiO2 surface. These theoretical predictions suggest the viability of replacing larger silver NCs with heterometallic trimers such as Ag2Au or AgAuCu, presenting new avenues for utilizing bio-nano hybrids at the surface for DSSC application.

Theoretical, structural, and electronic analyses of pyridin-based dyes for dye-sensitized solar cells applications.

The new series of donor-π-acceptor dyes have been designed using pyridine derivatives as a donor group and thienothiophene as a π-spacer group, which were linked via 10acceptor groups. The highest occupied molecular orbital energies range from - 6.177 to - 5.786eV, whereas the lowest unoccupied molecular orbital energies range from - 2.181 to - 3.664eV. A6 dye has smaller energy gap, lower hardness, higher electrophilicity index, and good photovoltaic performance than other sensitizers. The lowest dihedral angle is observed in A1, A2, A6, A7, and A8 which are appropriate for intramolecular charge transfer between the molecules. The A8 has higher light harvesting efficiency, which increases the photovoltaic efficiency of the designed dye. The A6, A7, and A8 dyes spend less time in the excited state, which means they emit photons more efficiently than other dyes. The interaction between donor to π-spacer (red line) parts of the dyes has the bonding interaction (positive), and π-spacer to acceptor (blue line) parts of the dyes have the bonding and antibonding (negative) behaviours. The dyes A5 and A9 have 305.79 and 357.71 times higher β0 values than urea (0.781 × 10-30 esu) molecules. The spectral properties of the A6 dye strongly affect the structural modification. The density functional theory (DFT) and time-dependent DFT (TD-DFT) approach B3LYP/6-311G (d,p) basic set were used to optimize the designed dyes. All the calculations are performed using Gauss view 6.0 and Gaussian 09 software. The density of state spectrum is plotted using Gauss sum 2.6.

Innovative microwave in situ approach for crystallizing TiO2 nanoparticles with enhanced activity in photocatalytic and photovoltaic applications

This investigation introduces an innovative approach to microwave-assisted crystallization of titania nanoparticles, leveraging an in situ process to expedite anatase crystallization during microwave treatment. Notably, this technique enables the attainment of crystalline material at temperatures below 100 °C. The physicochemical properties, including crystallinity, morphology, and textural properties, of the synthesized TiO2 nanomaterials show a clear dependence on the microwave crystallization temperature. The presented microwave crystallization methodology is environmentally sustainable, owing to heightened energy efficiency and remarkably brief processing durations. The synthesized TiO2 nanoparticles exhibit significant effectiveness in removing formic acid, confirming their practical utility. The highest efficiency of formic acid photodegradation was demonstrated by the T_200 material, reaching almost 100% efficiency after 30 min of irradiation. Furthermore, these materials find impactful application in dye-sensitized solar cells, illustrating a secondary avenue for the utilization of the synthesized nanomaterials. Photovoltaic characterization of assembled DSSC devices reveals that the T_100 material, synthesized at a higher temperature, exhibits the highest photoconversion efficiency attributed to its outstanding photocurrent density. This study underscores the critical importance of environmental sustainability in the realm of materials science, highlighting that through judicious management of the synthesis method, it becomes feasible to advance towards the creation of multifunctional materials.