Design Of Dye-sensitized Solar Cells Research Articles

A Green Approach to Natural Dyes in Dye-Sensitized Solar Cells.

Solar cells are pivotal in harnessing renewable energy for a greener and more sustainable energy landscape. Nonetheless, eco-friendly materials for solar cells have not been as extensive as conventional counterparts, highlighting a significant area for further investigation in advancing sustainable energy technologies. This study investigated natural dyes from cost-effective and environmentally friendly blueberries and mulberries. These dyes were utilized as alternative sensitizers for dye-sensitized solar cells (DSSCs). Alongside the natural dyes, a green approach was adopted for the DSSC design, encompassing TiO2 photoanodes, eco-friendly electrolytes, and green counter-electrodes created from graphite pencils and candle soot. Consequently, the best-optimized dye sensitizer was mulberry, with an output power of 13.79 µW and 0.122 µW for outdoor and indoor environments, respectively. This study underscored the feasibility of integrating DSSCs with sensitizers derived from readily available food ingredients, potentially expanding their applications in educational kits and technology development initiatives.

What is necessary to fill the technological gap to design sustainable dye-sensitized solar cells?

Analysis of properties and data – both known and missing – related to materials selection, life cycle assessment, and end-of-life reuse and recycling options for device components to achieve a sustainable design of dye-sensitized solar cells.

New Molecular Chemosensors Based on Niobium(V) 5,10,15,20-(Tetra-4-tert-butylphenyl)porphine for Detection of VOCs

Reactions of pyridine (Py) with (5,10,15,20-(tetra-4-tert-butylphenyl)porphinato)trichloroniobium(V) (Nb(Cl)3TtBuPP) and H+-bonded Nb(Cl)3TtBuPP (Nb(Cl)3TtBuPP···H+···Cl−) in toluene have been studied using spectroscopy (UV-vis, IR, 1H NMR, mass spectrometry, fluorescence), thermodynamics and kinetics. The process is a system of consecutive two- and one-way reactions of the two pyridine molecules bonding; the nature of this interactions is determined by the chemical structure of the initial niobium(V) porphyrin. The reactions have been completely quantitatively described, and the intermediate and final products spectral parameters used for the product chemical structure confirmation have been determined. It has been demonstrated that Nb(Cl)3TtBuPP and Nb(Cl)3TtBuPP···H+···Cl− are good candidates for use as optical and fluorescent chemosensors of VOCs (volatile organic compounds) and nitrogenous bases—building blocks of pharmaceuticals, food components, and environmental pollutants—with the following parameters: the stability constant of the complex with pyridine K = (1.99 ± 0.3) × 104 L2/mol2 and (2.8 ± 0.5) × 102 L/mol, relative optical response A = 0.91 and 0.35, detection limit of Py 1.74 × 10–3 and 4.05 × 10–4 mol/L, respectively. The results are applicable for use in the design of dye-sensitized solar cells (DSSCs) since the reaction studied is a model for self-assembly of donor–acceptor systems based on metalloprorphyrins and pyridyl derivatives of carbon nanoforms.

Geometric Effect of Grating-Patterned Electrode for High Conversion Efficiency of Dye-Sensitized Solar Cells

Photovoltaic devices that convert solar energy into electrical energy are a promising solution to resolve environmental problems the world is facing today. Among the various photovoltaic system, dye-sensitized solar cells (DSSCs) has been regarded as a new generation of the photovoltaic device due to the low cost and simple fabrication process. However, the current design of DSSCs shows insufficient conversion efficiency. To solve this problem, we increase the optical path length by trapping the incident light using a diffraction grating with high reflectance. We numerically investigate the effect of geometric parameters on the reflectance of diffraction gratings in DSSC system. Based on the simulation results, we propose an optimized geometry of diffraction grating that reflects the outgoing light and traps the incident light. The optimized geometry of the diffraction grating increase in the reflectance about 80% when it is compared to that without the diffraction grating.

Chemical Structure of Pyridine Complexes Of Oxo(5,10,15,20-Tetraphenyl-21H,23H-Porphinato) Niobium(V) Chloride According to Formation Thermodynamics/Kinetics And Spectroscopy Data

The equilibrium and the rate of stepwise reactions in the course of pyridine (Py) coordination by oxo(5,10,15,20-tetraphenylporphinato)niobium(V) chloride ((Cl)О=NbTPP) in toluene and the chemical structure of reaction products are studied using time-dependent titration, chemical kinetics, UV/Vis, IR, 1H NMR, and mass spectrometry methods. The interaction with Py is a complex system of simple, fast, reversible reactions of pyridine coordination (K1 = 2.2.105 l2/mol2, K2 = 5.2 l/mol) with subsequent nonreversible displacement of chloride ions into the second coordination sphere and cis–trans isomerization of axial ligands. A complete quantitative description of the interaction is obtained and spectral parameters were determined for intermediate and final products. Based on these data, the chemical structure of the latter is determined. The prospect of using (Cl)3NbTPP as a receptor for nitrogenous bases, the “building blocks” of pharmaceuticals and food components, as well as environmental pollutants, is substantiated. The obtained results are useful for the design of dye-sensitized solar cells (DSSCs), since the above reaction is a model of the self-assembly process of dipolar systems based on metalloporphyrins and pyridyl derivatives of carbon nanoforms.

Design of dye-sensitized solar cells using TiO2 pastes with different secondary particles sizes

Titanium dioxide (TiO2) pastes containing secondary particle with varying sizes are prepared by modulating the dispersion time of the dispersion liquid. The appearances, mesoscopic structures, and transmission spectra of the TiO2 layers constructed using these pastes depend on the sizes of the secondary particles. However, the dye-sensitized solar cells (DSSCs) constructed using different pastes show similar photoelectric conversion performances despite the different mesoscopic structures and transmission properties of the TiO2 layers. The DSSCs based on the experimental TiO2 pastes show lower photoelectric conversion efficiencies compared with the DSSC constructed using a commercially available reference paste. These results suggest that the primary TiO2 particles have a greater influence on the photoelectric conversion performance of the DSSC than the secondary particles. The incident photon-to-current conversion efficiency spectra of the DSSCs based on the TiO2 pastes exhibit a slight dependence on wavelength. Thus, it is possible that minor light-scattering effects resulting from the mesoscopic structure of TiO2 occur in the DSSCs constructed using the pastes. These results indicate that TiO2 pastes with fixed primary particle sizes but different secondary particle sizes can be used to change the appearance or design of DSSCs without affecting their photoelectric conversion performance.

Luminescent Spectral Conversion to Improve the Performance of Dye-Sensitized Solar Cells.

Relative to the broadband solar spectrum, a narrow range of spectral absorption of photovoltaic (PV) devices is considered an important determinant that the efficiency of light harvesting of these devices is less than unity. Having the narrowest spectral response to solar radiation among all PV devices, dye-sensitized solar cells (DSSCs) suffer severely from this loss. Luminescent spectral conversion provides a mechanism to manipulate and to adapt the incident solar spectrum by converting, through photoluminescence, the energies of solar photons into those that are more effectively captured by a PV device. This mechanism is particularly helpful for DSSCs because there is much flexibility in both the choice of the light-harvesting materials and the architecture of the DSSC. Here we review and discuss recent advances in the field of luminescent spectral conversion for DSSCs. The focus is on the architectural design of DSSCs, and the complications, advantages and new functionalities offered by each of their configurations are discussed. The loss mechanisms are examined and important parameters governing the spectral conversion mechanism of a DSSC are introduced.

Optical Excitation in Donor-Pt-Acceptor Complexes: Role of the Structure.

The optical properties of the Pt complexes in the form of donor-metal-acceptor (D-M-A) were studied at the first-principles level. Calculated results show that for the frontier molecular orbitals (MOs) of a D-M-A structure the energies of unoccupied frontier MO can be mainly determined by the interaction between M and A, whereas the M-A and M-D interactions both determine the energies of occupied frontier MO. By developing a straightforward transition dipole decomposition method, we found that not only the local excitations in D but also those in A can significantly contribute to the charge-transfer (CT) excitation. Furthermore, the calculations also demonstrate that by tuning the dihedral angle between D and A the transition probability can be precisely controlled so as to broaden the spectrum region of photoabsorption. For the D-M-A molecule with a delocalized π system in A, the CT excitation barely affects the electronic structures of metal, suggesting that the oxidation state of the metal can be kept during the excitation. These understandings for the optical properties of the D-M-A molecule would be useful for the design of dye-sensitized solar cells, photocatalysis, and luminescence systems.

Enhancement of power conversion efficiency of dye sensitized solar cells by modifying mesoporous TiO2 photoanode with Al-doped TiO2 layer

Abstract The optimization of charge transfer at the TiO2/dye/electrolyte interface is crucial to the design of dye-sensitized solar cells. In this paper, the Al doped TiO2 layers were coated on the mesoporous TiO2 films by a chemical bath deposition process, followed by sintering at 500 °C. Its performance as the TiO2/dye/electrolyte interface layer was investigated. The analysis results reveals that the Al doped TiO2 coating can reduce the oxygen vacancy-Ti3+ concentrations in the photoanodes significantly, which is beneficial to suppress the back electron transfer process from TiO2 to electrolyte. Furthermore, the electron mobility of the modified photoanodes was increased. Consequently, the dye sensitized solar cells (DSSC) based on the photoanodes modified by Al-doped TiO2 coating show an improvement on both enhancing the electron transport and suppressing the charge recombination process. The dye sensitized solar cell based on the photoanode modified by 1.0 mol% Al-doped TiO2 layer, shows a power conversion efficiency as high as 7.66%, increasing 9.12% compared with the unmodified reference cell. Finally, our works show a facile and scalable technique to further optimize interfacial charge transfer process in dye sensitized solar cells.

Suspension of electron–hole recombination in a dye-sensitized solar cell through simultaneous optimization of micro and electronic structures

This study sought to optimize the structures in a working electrode at the micro- as well as electron-scales with the aim of suspending electron–hole recombination in order to increase the power conversion efficiency of dye-sensitized solar cells (DSSCs). Based on a review of the literature and basic theory of electrical physics, we were able to establish a linear relationship between open-circuit photovoltage (Voc) and fill factor (FF), which led to the formulation of two equations: one of which relates FF directly to series resistance (rs) and the other relates FF to shunt resistance (rsh). This led to the formulation of a new DSSC design strategy with the aim of increasing Voc of the DSSC by reducing rh (part of rs) as well as increasing rsh. The proposed design strategy is based on the fabrication of a multilayer TiO2 microstructure in conjunction with electron orbital hybridization. This strategy was implemented using fifteen sets of experiments aimed at simultaneously optimizing structures in working electrodes at the micro- and electron-scales. The resulting design rules and mechanisms underlying carrier transport provide practical guidance and critical knowledge required for the further development of next generation photo electron devices.

텍스타일 형 염료감응 태양전지의 광전극 설계 및 전기적 특성분석에 관한 연구

텍스타일 형 염료감응 태양전지의 광전극 설계 및 전기적 특성분석에 관한 연구

Photoemission Studies on N-Substituted Dithienylated Phenothiazines.

Dithienylated phenothiazines (DTPTs) with different functional groups attached to the central nitrogen atom are presented as a class of versatile metal-free chromophores for the design of dye-sensitized solar cells (DSSCs) and organic light-emitting diodes (OLEDs). The electronic characteristics of spin-coated thin films on polycrystalline gold were studied using photoelectron spectroscopy assisted by theoretical calculations, scanning force microscopy, and UV/Vis spectroscopy. Complementary fluorescence spectra show light emission in the blue region (465 nm). The absorption properties and good hole-transporting abilities make DTPTs feasible hole-transporting materials (HTM) and metal-free chromophores in UV-sensitive solar cell designs.

Chemically Robust Phthalocyanines: Photosensitizer and Electron Shuttle in Solid State Dye Sensitized Solar Cells

ABSTRACTA completely solid state dye sensitized solar cell (DSSSC) is proposed in which chemically robust phthalocyanine (Pc) sensitizers, F16ZnPc and F40ZnPc, are sandwiched between n-TiO2 and p-NiO. While the energy conversion efficiencies of conventional Grätzel cells are continually increasing, the DSSSC design effectively solves the long term stability issues of the volatile liquid electrolyte. Through analysis of the electronic structure of the Pc|semiconductor systems, the free energy associated with hole injection into the valence band of NiO upon photoexcitation of the sensitizer and electron injection into the conduction band of TiO2 from the reduced form of the sensitizer as well as the competing charge recombination processes are calculated. Thermodynamically, the charge injection processes are found to be favored over the undesired charge recombination processes. These findings suggest promising energy conversion for the NiO|Pc|TiO2 DSSSC.

Spectroscopy of Donor−π–Acceptor Porphyrins for Dye-Sensitized Solar Cells

A recent improvement in the design of dye-sensitized solar cells has been the combination of light-absorbing, electron-donating, and electron-withdrawing groups within the same sensitizer molecule. This dye architecture has proven to increase the energy conversion efficiency of the cells, leading to record efficiency values. Here we investigate a zinc(II)-porphyrin-based dye with triphenylamine donor groups and carboxyl linkers for the attachment to an oxide acceptor. The unoccupied energy levels of these three moieties are probed selectively by element-sensitive X-ray absorption spectroscopy at the K-edges of nitrogen and carbon. These results are complemented by ultraviolet/visible spectroscopy to obtain the optical band gap and the occupied molecular levels. Density functional theory and time-dependent density functional theory are employed to obtain a detailed understanding of the X-ray and optical absorption spectra. The attachment of electron-donating groups to the porphyrin ring significantly delocalizes the highest occupied molecular orbital (HOMO) of the molecule. This leads to a spatial separation between the HOMO and the lowest unoccupied molecular orbital (LUMO), with the HOMO having significant weight in the amine donors, while the LUMO remains localized in the porphyrin ring and the acceptor group. Such spatial separation of the frontier orbitals reduces the recombination rate of photoinduced electrons and holes, thus enhancing the energy conversion efficiency.

Anharmonic vibrations of the carboxyl group in acetic acid on TiO2: implications for adsorption mode assignment in dye-sensitized solar cells

We compute frequencies of vibrations of the carboxyl group in acetic acid adsorbed on the anatase (101) surface of TiO2 in two monodentate and the bidentate bridging configurations relevant for the adsorption of dyes on TiO2 in dye-sensitized solar cells (DSSCs). The ability to assign these vibrations and determine the adsorption configurations is critical for the design of DSSCs. Anharmonicity and coupling of four or five modes are taken into account by using a new version of the method of Manzhos and Carrington that computes vibrational spectra directly from discrete ab initio data, bypassing the construction of a potential energy surface, and using parameterized basis functions and rectangular collocation. We show that the method enables a routine analysis of anharmonic vibrations of practical importance in large systems. A sub-cm(-1) accuracy is achieved by using as few as 70 basis functions and 500 single-point energies. The calculations are doable on a desktop computer. This is the first time vibrational spectra for different adsorption sites of an organic molecule have been computed and compared without neglecting anharmonicity and coupling of the attaching group.

Design of Dye-Sensitized Solar Cell by Inserting Single-Walled Carbon Nanotubes

In this paper, a solid-state dye sensitized solar cell (DSSC) based on carbon nanotubes by inserting N719 dye molecules has been designed for operating at 300oK and 330oK temperatures. The role of carbon nanotubes as hole and electron conducting agents and dye molecules as absorber of solar radiation and hole-electron pair producing agents has been discussed. After inserting N719 dye, parameters of the cell such as absorption coefficient of both layers (ZNO+SWNT, P3HT+SWNT), current density of solar cell , internal and external quantum efficiency of P3HT+SWNT layer have been obtained at 300oK and 330oK, numerically. Then, improvement value of energy conversion efficiency of the cell has been compared after inserting carbon nanotubes.

Recent progress on tandem structured dye-sensitized solar cells

Tandem structured dye-sensitized solar cells (DSSCs) can take full advantage of sunlight, effectively broadening the absorption spectrum of the cell, resulting in a higher open circuit voltage or short circuit current than that of the conventional DSSC with single light absorber. The theoretical maximum efficiency is therefore suggested to be over the Schottky-Queisser limit of 33%. Accordingly, tandem design of DSSC is thought to be a promising way to break the performance bottleneck of DSSC. Besides, the tandem designs also broaden the application diversity of DSSC technology, which will accelerate its scale-up industrial application. In this paper, we have reviewed the recent progress on photo-electrochemical applications associated with kinds of tandem designs of DSSCs, in general, which are divided into three kinds: “n-type DSSC + n-type DSSC,” “n-type DSSC + p-type DSSC” and “n-type DSSC + other solar conversion devices.” The working principles, advantages and challenges of these tandem structured DSSCs have been discussed. Some possible solutions for further studies have been also pointed out together.

Design of dye-sensitized solar cells integrated in composite panel subjected to bending

This article discusses the design of airborne dye-sensitized solar cell (DSSC) panel integrated in the airplane composite panel which is subjected to mechanical dynamic loading so that the DSSC will function continuously as airborne energy harvester. This article consists of two parts, first synthesis of more rubut DSSC, and then its integration into a composite panel with durability demonstrated.

Zirconium(IV) and Hafnium(IV) Porphyrin and Phthalocyanine Complexes as New Dyes for Solar Cell Devices

Metalloporphyrin and metallophthalocyanine dyes ligating Hf(IV) and Zr(IV) ions bind to semiconductor oxide surfaces such as TiO(2) via the protruding group IV metal ions. The use of oxophylic metal ions with large ionic radii that protrude from the macrocycle is a unique mode of attaching chromophores to oxide surfaces in the design of dye-sensitized solar cells (DSSCs). Our previous report on the structure and physical properties of ternary complexes wherein the Hf(IV) and Zr(IV) ions are ligated to both a porphyrinoid and to a defect site on a polyoxometalate (POM) represents a model for this new way of binding dyes to oxide surfaces. The Zr(IV) and Hf(IV) complexes of 5,10,15,20-tetraphenylporphyrin (TPP) with two ligated acetates, (TPP)Hf(OAc)(2) and (TPP)Zr(OAc)(2), and the corresponding metallophthalocyanine (Pc) diacetate complexes, (Pc)Hf(OAc)(2) and (Pc)Zr(OAc)(2), were evaluated as novel dyes for the fabrication of dye-sensitized solar cells. Similarly to the ternary complexes with the POM, the oxide surface replaces the acetates to affect binding. In DSSCs the Zr(IV) phthalocyanine dye performs better than the Zr(IV) porphyrin dye, and reaches an overall efficiency of ~ 1.0%. The Hf(IV) dyes are less efficient. The photophysical properties of these complexes in solution suggested energetically favorable injection of electrons into the conduction band of TiO(2) semiconductor nanoparticles, as well as a good band gap match with I(3) (-)/I(-) pair in liquid 1-butyl-3-methyl imidazolium iodide. The combination of blue absorbing TPP with the red absorbing Pc complexes can increase the absorbance of solar light in the device; however, the overall conversion efficiency of DSSCs using TiO(2) nanoparticles treated with a mixture of both Zr(IV) complexes is comparable, but not greater than, the single (Pc)Zr. Thus, surface bound (TPP)Zr increases the absorbance in blue region of the spectra, but at the cost of diminished absorbance in the red in this DSSC architecture.

Simulation of Dye-sensitized Solar Cells Based on a Population Dynamics Model

Dye-sensitized solar cells are electrochemical devices with very interesting properties that provide an alternative to the conventional semiconductor solar cell technology. However, the details of the charge transport mechanisms, which include both electronic and ionic transport, are not yet fully understood. In this paper, we present a novel approach to dye-sensitized solar cell modeling and simulation which is based on population dynamics models that have recently been extensively used to model reactions between biological molecules. It is shown that the proposed model can be used to simulate the operation of dye-sensitized solar cells and produces I-V characteristics that are in qualitative agreement with the experimental ones. Furthermore, the model presented here can be used to optimize the characteristics and the design of dye-sensitized solar cells. Keywords: Dye-sensitized solar cells, modeling, simulation, population dynamics