Characteristics Of Dye-sensitized Solar Cells Research Articles

Investigation on the Thickness Effect of TiO<sub>2 </sub>Photo- Anode on Dye-Sensitized Solar Cell Performance

Dye-sensitized solar cell (DSSC) has attracted immense interest over the past decade due to its low cost and simplicity as a renewable energy source. In DSSC, the photo-anode that governs the collection and transportation of photo-excited electrons plays a critical role in determining the cell performance. In particular, the thickness of the photo-anode is known to be one of the decisive factors in dictating cell efficiency. In this paper, the thickness effect of TiO2 film as photo-anode on the photovoltaic performance of DSSC is studied. The TiO2 films were characterized by UV-visible absorbance spectroscopy to correlate the film thickness with the light harvesting efficiency of DSSC. The effects of film thickness on the photocurrent density-voltage characteristics of DSSCs were also investigated. The optimized thickness (4m) of the TiO2 film was discovered to be the best compromise between the amount of dye loading and the electron transport resistance.

Synthesis and photovoltaic properties of new Ru(II) complexes for dye-sensitized solar cells

Two groups Ru(II) complexes, (1A-C and 2A) (A-C = 2,6-bis(2-benzimidazolyl)pyridines, bbpy, with various substituents at 2-, 5-, and 6-positions) have been prepared and applied for dye–sensitized solar cells (DSSC). The compounds were characterized by various techniques. The optical and electrical properties of sensitizers were investigated with UV–Vis absorption spectroscopy and cyclic voltammetry. High power conversion efficiencies up to 5.16%, have been achieved with 2Ae. Current–voltage characteristics of DSSCs clearly affected by the changing of the ligands at sensitizers. Additionally, computational studies show that locations of frontier molecular orbitals are significantly important for power–conversion efficiencies in DSSCs.

Efficient and Stable Photovoltaic Characteristics of Quasi-Solid State DSSC using Polymer Gel Electrolyte Based on Ionic Liquid in Organosiloxane Polymer Gels

Dye-Sensitized Solar Cell (DSSC) is still one of the promising solar cell types among the third generation of solar cells because of easiness of fabrication and variety of available materials. In this type of solar cell, the electrolyte is one of the important components for regenerating excited dyes and transporting electric charge carriers to the counter electrode. Indeed, the power conversion efficiency of DSSC can be then significantly affected by the chemical and physical properties of the electrolyte. The simplest electrolyte system of an I-/I3- redox couple in an organic solvent, however, has some drawbacks due to corrosive properties, volatile and leakage problem. Use of solid phase or gel phase electrolyte may overcome those problems, but it is often considered to suppress the efficiency due to low ion diffusion. Here, we report the photovoltaic characteristics of DSSC using polymer gel electrolyte (PGE), which is composed of ionic liquid and an organosiloxane polymer gel. The better cell performance with power conversion efficiency of about 6% has been obtained by optimizing the mesoporous size of the TiO2 layer and the PGE viscosity.

Mechanochemical synthesis of melamine doped TiO2 nanoparticles for dye sensitized solar cells application

In a quest for developing new material with performance of dye sensitized solar cells (DSSC) a non-metallic doping i.e., of nitrogen was carried out to commercial TiO2 nanoparticle using simple, facile and sustainable mechanochemistry method. Melamine was used as source of nitrogen and different weight percentages (10, 30, 50, 70 and 90%), mixed with TiO2 mechanically in a ball mill for 12 h at an speed of 500 rotations per minute followed by annealing at 550 °C for 2 h under constant N2 flow. The post nitrogen doping structural analysis indicated anatase phase of TiO2.The morphological observations by transmission electron microscopy did not show change due to melamine and particle size remains less than 30 nm. N-doping resulted in an increased wavelength of peak absorption from 334 nm to about 350 nm and shifting of absorption edge from UV (~ 400 nm) to visible region (~ 500 nm) resulting in the reduction of the band gap from 3.14 to 2.43 eV which is supported by XPS and Tauc plot analysis. The functional analysis reveals amide bond at higher melamine concentration. The DSSC characteristics were measured with source-meter coupled with simulated light source which shows a significant increase of cell efficiency from 26 with 10% of melamine to that of 86 with 90% melamine. The increase in efficiency was linear with increasing nitrogen doping concentration. The study suggested that melamine can be used as a suitable N-dopant source for improved photoconversion properties that can help engineer to develop a device with enhanced performance.

Structural and chemical analysis of TiO2 nanotube surface for dye-sensitized solar cells

One-dimensional TiO2 nanotube (TNT) arrays were fabricated on fluorine-doped tin oxide glass substrate as the photoanodes for dye-sensitized solar cells (DSCs) using one-step ZnO nanorods template method. The depth profile analysis using X-ray photoelectron spectroscopy and ion sputtering indicated that a small amount of Zn species was attached on the TNT surface. Relationship of the properties of the TNT surface with the Zn residue and the photovoltaic characteristics of DSCs were investigated. Residual Zn species on TNT improve the open circuit voltage of the DSCs. A maximum open circuit voltage of 0.876 V was achieved, which is close to the theoretical maximum of the TiO2-based DSCs. However, photocurrent density was decreased significantly for the high-Zn-amount sample. It was revealed that the surface Zn species were divalent oxides and the amount of surface hydroxyl group was increased in conjunction with the Zn amount. Slight increase of the dye amount was found for the high Zn amount sample. It was expected that decrease in injection probability of the photo-excited electrons into TNT was the dominant reason for the photocurrent decrease.

Effect of composition of chlorophyll and ruthenium dyes mixture (hybrid) on the dye-sensitized solar cell performance

The fabrication of dye-sensitized solar cell (DSSC) has been conducted by varying the composition of natural dye from moss chlorophyll (Bryophyte) and synthesis dye from ruthenium complex N719. The sandwich structure of DSSC consists of the working electrode using TiO2, dye, electrolyte, and counter electrode using carbon. The composition of chlorophyll and synthesis dyes mixture were 100% and 0%, 80% and 20%, 60% and 40%, 40% and 60%, and 20% and 80%. The UV-Vis absorption spectra of moss chlorophyll showed the first peak in the wavelength range of 450-500 nm and the second peak at wavelength of 650-700 nm. The peak value of absorbance at wavelengths of 450-500 nm was 6.1004 and at wavelengths of 650-700 nm was 3.5835. The IPCE characteristic curves showed the absorption peak of photon for DSSCs occurred at wavelength of 550-650 nm. It considered that photon in this wavelength can contribute dominantly to produce the optimum electrons. The I-V characteristics of DSSCs with composition of chlorophyll and synthesis dyes mixture of 100% and 0%, 80% and 20%, 60% and 40%, 40% and 60%, and 20% and 80% resulted the efficiency of 0.0022; 0.0194; 0.0239; 0.0342; and 0.0414, respectively. It suggested that the addition of a little composition of the ruthenium complex dye into moss chlorophyll dye can increase the efficiency significantly.

Efficient dye-sensitized solar cells from mesoporous zinc oxide nanostructures sensitized by N719 dye

Dye-sensitized solar cells (DSCs) have attracted a great deal of attention due to their low-cost and high power conversion efficiencies. They usually utilize an interconnected nanoparticle layer of TiO2 as the electron transport medium. From the fundamental point of view, faster mobility of electrons in ZnO is expected to contribute to better performance in DSCs than TiO2, though the actual practical situation is quite the opposite. In this research, we addressed this problem by first applying a dense layer of ZnO on FTO followed by a mesoporous layer of interconnected ZnO nanoparticle layer, both were prepared by spray pyrolysis technique. The best cell shows a power conversion efficiency of 5.2% when the mesoporous layer thickness is 14 μm and the concentration of the N719 dye in dye coating solution is 0.3 mM, while a cell without a dense layer shows 4.2% under identical conditions. The surface concentration of dye adsorbed in the cell with a dense layer and that without a dense layer are 5.00 × 10−7 and 3.34 × 10−7 mol/cm2, respectively. The cell with the dense layer has an electron lifetime of 54.81 ms whereas that without the dense layer is 11.08 ms. As such, the presence of the dense layer improves DSC characteristics of ZnO-based DSCs.

Study on Surface and Crystallinity of TiO₂ Microspheres as the Photoanode of Dye-Sensitized Solar Cells.

In this study, Titanium dioxide (TiO2) microspheres were synthesized by a hydrothermal method from the same precursor: titanium sulfate. Two different TiO2 microspheres with different surface and crystallinity were fabricated by adding different additives as the photoanode of dye-sensitized solar cells (DSSCs). The growth mechanisms of the TiO2 microspheres were discussed. The effect of surface status and the crystallinity of the TiO2 microspheres on the photovoltaic characteristic of DSSCs were investigated. It was found that when the TiO2 microsphere with loose construction and rough surfaces along with better crystallinity was applied on photoanode, the DSSC exhibited better photoelectric performance than the DSSC with dense TiO2 microsphere photoanode. TiO2 microsphere with loose construction and rough surface applied to photoanode, the DSSC showed photoelectric conversion performance of 3.83% which is 53.8% higher than DSSC with dense and smooth TiO2 microsphere photoanode, and it is also superior to the DSSC with P25 photoanode.

Symbiotic organism search algorithm for simulation of J-V characteristics and optimizing internal parameters of DSSC developed using electrospun TiO2 nanofibers

In the present investigation, the recently developed, simple, robust, and powerful metaheuristic symbiotic organism search (SOS) algorithm was used for simulation of J-V characteristics and optimizing the internal parameters of the dye-sensitized solar cells (DSSCs) fabricated using electrospun 1-D mesoporous TiO2 nanofibers as photoanode. The efficiency (η = 5.80%) of the DSSC made up of TiO2 nanofibers as photoanode is found to be ∼ 21.59% higher compared to the efficiency (η = 4.77%) of the DSSC made up of TiO2 nanoparticles as photoanode. The observed high efficiency can be attributed to high dye loading as well as high electron transport in the mesoporous 1-D TiO2 nanofibers. Further, the validity and advantage of SOS algorithm are verified by simulating J-V characteristics of DSSC with Lambert-W function.

Preparation of carbon nanofibers supported MoO2 composites electrode materials for application in dye-sensitized solar cells

In this work, a counter electrode (CE) made from a composite of electrospun carbon nanofibers (CNs) and MoO2 nanoparticles has been discussed for the first time as an efficient and low-cost Pt-free counter electrode (CE) for dye-sensitized solar cells (DSSCs). MoO2/carbon nanofiber composites (MoO2/CNs) were successfully prepared via a facile one-step hydrothermal method. The obtained MoO2/carbon electrode showed good chemical stability, lower charge transfer resistance and higher electrocatalytic activity as compared to the conventional Pt electrodes. The characteristics of DSSCs based on MoO2/CNs electrodes were analyzed using photocurrent density-voltage, cyclic voltammetry, Tafel polarization curve and electrochemical impedance spectroscopy measurements. The experimental results revealed that the MoO2/CNs electrodes exhibited the optimal electrode characteristics. The DSSCs based on MoO2/CNs electrodes displayed better photovoltaic conversion efficiency (7.6%) than the Pt counter electrodes (7.34%).

Enhanced electron collection efficiency of nanostructured dye‐sensitized solar cells by incorporating TiO2 cubes

AbstractHerein, enhancement of dye‐sensitized solar cell (DSC) performance is reported by combining the merits of the dye loading of TiO2 nanoparticles and light scattering, straight carrier transport path, and efficient electron collection efficiency of TiO2 cubes. We fabricate DSC devices with various arrangement styles and compositions of the electrodes in the forms of monolayer and double layer films. For this purpose, the solvothermal synthesized TiO2 cubic particles (100‐600 nm) are employed as the scattering layer, whereas TiO2 nanoparticles (15‐30 nm) synthesized via a combination of solvothermal and sol‐gel routes are used as the active layer of devices. We improve the photovoltaic characteristics of DSCs by two mechanisms. First, the light harvesting of DSC devices made of nanoparticles is improved by controlling the thickness of monolayer films, reaching the highest efficiency of 7.0%. Second, the light scattering and electron collection efficiency are enhanced by controlling the composition of double layer films composed of mixtures of TiO2 nanoparticles and cubes, obtaining the maximum efficiency of 8.21%. The enhancements are attributed to balance between charge transfer resistance and charge recombination of photo‐generated electrons as well as dye loading and light scattering.

Studies on up-converting Ho3+-Yb3+-F− tri-doped TiO2 nanoparticles for enhancing efficiency of dye-sensitized solar cells

Titanium dioxide (TiO2) nanoparticles (NPs) tri-doped with different concentrations of Ho3+, Yb3+ and F− ions (abbreviated as UC-F-TiO2 NPs) were synthesized for applications in dye-sensitized solar cells (DSSCs). These UC-F-TiO2 NPs were synthesized using hydrosol−hydrothermal method. The phase structure, morphology and luminescent property of UC-F-TiO2 NPs are characterized using X-ray diffraction, Raman spectroscopy, transmission electron microscopy, scanning electron microscopy and photoluminescence (PL) spectroscopy. The results indicated that the UC-F-TiO2 NPs are mixed phases of anatase and rutile with approximate sizes in the range from 10 to 15 nm. Photoluminescence (PL) measurements confirmed that the UC-F-TiO2 NPs have a good up-converting (UC) property. The prepared powders were used to make photo-anodes for DSSCs. The DSSCs assembled with a bilayer-structured UP-F-TiO2 NP photo-anode has a 15.2% enhancement in short-circuit current density and a 29.7% enhancement in conversion efficiency comparing with DSSCs assembled with un-doped TiO2 photo-anodes. The photocurrent improvement is due to an increase in the light-harvesting capacity of the photo-anodes attained through the up-converting property of UC-F-TiO2 NPs, which was demonstrated by PL and IPCE measurements. The result suggests that the incorporation of up-converting nanoparticles into photo-anode is an effective approach to improve the photovoltaic characteristics of DSSCs.

Factors Affect Dye Sensitized Solar Cells performance

Recently, dye-sensitized solar cells (DSSCs) have received great attention for their simple fabrication process, low production costs and, relatively high conversion efficiency. DSSC are a combination of materials, consisting of a transparent electrode coated with a dye-sensitized mesoporous film of nanocrystalline particles of TiO2, an electrolyte containing a suitable redox couple and an electrode. In order to optimize DSSC performance, it is important to fully understand the factors which affect the key features of DSSC characteristics. This paper presents an overview of the construction of a dye-sensitized solar cell, operating principle of DSSC, DSSC performance and, investigates the most important parameters which affect Dye-Sensitized Solar Cells performance.

Fabrication of dye natural as a photosensitizers in dye-sensitized solar cells (DSSC)

<p class="Abstract">The purpose of this study was to obtain optical properties (absorption spectrum) and electrical properties (photoconductivity) of organic dyes in DSSC performance. optical and electrical properties were tested by using UV-Visible Spectrophotometer and Elkahfi 1601 PC 100 / IV meter, respectively, while Keithley Type 2600A is used for the characterization of DSSC. This study is a great base to explore and investigate the development of DSSC solar cells using natural dyes (organic). Spectra optimal absorption and photoconductivity produced by natural dyes (organic). The results of this study indicate that the absorption spectrum of natural dyes (organic) in the range of 300-500 nm. electrical characteristics (I-V) of the increase in linear dye under illumination. I-V characteristics of DSSC from organically produced natural dyes to color the biggest-mangosteen obtained Voc of 565 mV; JSC = 1.52 A / m2; FF = 0.12; and η_ef is approximately 0.09%, respectively,. The conclusion of this study, natural dyes (organic) can be an attractive alternative as a dye.</p>

Fabrication of dye natural as a photosensitizers in dye-sensitized solar cells (DSSC)

<p class="Abstract">The purpose of this study was to obtain optical properties (absorption spectrum) and electrical properties (photoconductivity) of organic dyes in DSSC performance. optical and electrical properties were tested by using UV-Visible Spectrophotometer and Elkahfi 1601 PC 100 / IV meter, respectively, while Keithley Type 2600A is used for the characterization of DSSC. This study is a great base to explore and investigate the development of DSSC solar cells using natural dyes (organic). Spectra optimal absorption and photoconductivity produced by natural dyes (organic). The results of this study indicate that the absorption spectrum of natural dyes (organic) in the range of 300-500 nm. electrical characteristics (I-V) of the increase in linear dye under illumination. I-V characteristics of DSSC from organically produced natural dyes to color the biggest-mangosteen obtained Voc of 565 mV; JSC = 1.52 A / m2; FF = 0.12; and η_ef is approximately 0.09%, respectively,. The conclusion of this study, natural dyes (organic) can be an attractive alternative as a dye.</p>

Natural Deys from Fruit Waste as a Sensitizer for Dye Sensitized Solar Cell (DSSC)

Dye-sensitized solar cell (DSSC) is one of the potential candidates for the next generation solar cells. One of the most attractive features of the DSSC is the low production costs. The utilization of natural dyes is a new area for investigation due to their unique capability to absorb photons from natural sunlight or artificial light and convert it into electric current. The purpose of this study is to determine the potential of natural dye from red dragon fruit waste as a dye sensitizer. Red dragon fruit peel is initially extracted using methanol and the solution absorption spectra then is characterized using UV-Vis spectrophotometer. The absorption spectra is measured within a wavelength range of 400-800 nm. The characterization results show that the maximum absorption spectrum is at a wavelength of 446 nm. The natural dye solution then is used to immerse Fluorine Tin Oxide (FTO) coated with titanium dioxide (TiO2). The glass FTO is immersed in the dye solution for 24 hours. DSSC then is prepared by sandwiching the working electrode and counter electrode. An electrolyte solution is used to fill the interface between the two electrodes. The current and voltage (I-V) characteristics of DSSC is finally measured using amperemeter and voltmeter. The results indicated that the natural dye from the peel of red dragon fruit has potential as a dye sensitizer. Further research is still required to improve the performance of the DSSC.

Performance Enhancement of Dye-Sensitized Solar Cells Using a Natural Sensitizer

Dye-sensitized solar cells (DSSCs) based on natural sensitizers have become a topic of significant research because of their urgency and importance in the energy conversion field and the following advantages: ease of fabrication, low-cost solar cell, and usage of nontoxic materials. In this study, the chlorophyll extracted from papaya leaves was used as a natural sensitizer. Dye molecules were adsorbed by TiO2 nanoparticle surfaces when submerged in the dye solution for 24 h. The concentration of the dye solution influences both the amount of dye loading and the DSSC performance. The amount of adsorbed dye molecules by TiO2 nanoparticle was calculated using a desorption method. As the concentration of dye solution was increased, the dye loading capacity and power conversion efficiency increased. Above 90 mM dye solution concentration, however, the DSSC efficiency decreased because dye precipitated on the TiO2 nanostructure. These characteristics of DSSCs were analyzed under the irradiation of 100 mW/cm2. The best performance of DSSCs was obtained at 90 mM dye solution, with the values of Voc, Jsc, FF, and efficiency of DSSCs being 0.561 V, 0.402 mA/cm2, 41.65%, and 0.094%, respectively.

Effect of Nanotube Morphologies on Multi-Walled Carbon Nanotubes Based Counter Electrode for Dye-Sensitized Solar Cell.

Multi-walled carbon nanotubes (MWCNTs) with different morphologies were introduced into dyesensitized solar cell (DSSC) as low-cost substitutes for Pt counter electrode (CE). The effect of length and orientation of MWCNTs on the power conversion efficiency (PCE) of DSSC with MWCNTs CE were studied by measuring electrochemical impedance spectroscopy of MWCNTs and the photocurrent density–voltage (J–V ) characteristics of DSSC in this study. Results revealed that the long MWCNTs showed better electrocatalytic activity of reducing triiodide ions than short MWCNTs and yielded the power conversion efficiency of 2.42%. When the aligned multi-walled carbon nanotubes (AMWCNTs) with the same length as the long MWCNTs were used to prepare the CE, the power conversion efficiency of the DSSC reaches 2.95%. In order to further improve the performance of the DSSC, the processing of photoanode and counter electrode were adjusted. The power conversion efficiency of the cell with AMWCNTs as CE prepared by adjusted processing achieved 3.95% and the short circuit current density is superior to the DSSC with Pt as CEs, and it indicated the adjusted processing is beneficial to increase the overall performance of the dye-sensitized solar cell.

Influence of thin film thickness of working electrodes on photovoltaic characteristics of dye-sensitized solar cells

This paper presents the study of the influence of thin film thickness of working electrodes on the photovoltaic characteristics of dye-sensitized solar cells. Titanium dioxide (TiO2) thin films, with the thickness from 7.67 to 24.3 μ m, were used to fabricate the working electrodes of dye-sensitized solar cells (DSSCs). A TiO2 film was coated on a fluorine-doped tin oxide (FTO) conductive glass substrate and then sintered in a high-temperature furnace. On the other hand, platinum (Pt) solution was coated onto an FTO substrate for the fabrication of the counter electrode of a DSSC. The working electrode immersed in a dye, the counter electrode, and the electrolyte were assembled to complete a sandwich-structure DSSC. The material analysis of the TiO2 films of DSSCs was carried out by scanning electron microscopy (SEM) and ultraviolet-visible (UV-Vis) spectroscopy, while the photovoltaic characteristics of DSSCs were measured by an AM-1.5 sunlight simulator. The light transmittance characteristics of the TiO2 working electrode depend on the TiO2 film thickness. The thin film thickness of the working electrode also affects the light absorption of a dye and results in the photovoltaic characteristics of the DSSC, including open-circuited voltage ( V OC), short-circuited current density ( J SC), fill factor, and photovoltaic conversion efficiency.

Poly(o-methoxyaniline) doped with an organic acid as cost-efficient counter electrodes for dye-sensitized solar cells

In this study, the conductive polymer poly(o-methoxyaniline) (POMA) was doped with an organic acid, 1S-(+)-camphorsulfonic acid (CSA), and used to fabricate counter electrodes for dye-sensitized solar cells (DSSCs). The effects of POMA doped with various weight ratios of CSA on the efficiency of DSSCs were investigated. The properties of the POMA and POMA-CSA electrodes were comprehensively analyzed. The POMA-CSA electrodes exhibited increased surface roughness, increased crystallinity, and decreased impedance. The characteristics of DSSCs based on POMA-CSA electrodes were analyzed using photocurrent density–voltage, incident monochromatic photon-to-current conversion efficiency, and electrochemical impedance spectroscopy measurements. The experimental results revealed that the POMA-CSA(16%) electrodes exhibited the optimal electrode characteristics. The DSSC based on POMA-CSA(16%) counter electrodes reached an efficiency of 8.76%, which was higher than that of DSSCs with platinum counter electrodes.