Dye Solar Cells Research Articles

Nanocellulose and Nanochitin Cryogels Improve the Efficiency of Dye Solar Cells

Biobased cryogel membranes were applied as electrolyte holders in dye solar cells (DSC) while facilitating carrier transport during operation. They also improved device performance and stability. F...

Improved Performance of Dye-Sensitized Solar Cells With TiO2 Nano-Particles by Using The Carrot as a Dye Solar Cell Application

The aims of the research to were know performance of Dye-Sensitized Solar Cell (DSSC) using the dye of carrots (Daucus carota) as a photosensitizer with a variation of dye deposition area with spin coating techniques. The structure of the samples as a sandwich consisting of the working electrode titanium dioxide (TiO2), dye, electrodes of platinum (Pt) and the electrolyte sandwiched between two electrodes. Test absorbance dye using UV-Visible Spectrophotometer Lambda 25, using a two-point conductivity test probes El Kahfi 100 and characterization test IV using a Keithley 2602A.. DSSC fabrication has been done using dye extract of carrots (Daucus carota) with a variety of solvent technique spin coating. The results show that dye extract of carrots (Daucus carota) have an absorbance spectrum of 380-520 nm range. From the results of the test using AM Simulator 1.5G (100 mW/ cm2) diesel simulator, it was found that the volume of TiO2 precursors affected the performance of DSSC solar cells and the overall conversion efficiency was 0.021% for the carrots (Daucus carota) dye with ethanol solvent and 0.037% for the carrots (Daucus carota) dye by solvent acetone.

Metal-pigment complex derived from natural dye of anthocyanin: a potential candidate for DSSC photosensitizer

This research is aimed to synthesize iron-pigment complex of anthocyanin extracted from the peel of red dragon fruit (Hylocereus polyrhizus). The targeted iron-complex was then evaluated to confirm its potential use as photosensitizer on Dye Sensitize Solar Cell (DSSC). The electronic absorption spectrum of the red dragon fruit extract showed a broad band spanning from 400 nm to 600 nm and a band maximum at 533 nm. This band was then evaluated to find out the energy of electronic transition; an excitation from highest occupied molecular orbital (HOMO; valence band) toward lowest unoccupied molecular orbital (LUMO; conduction band). The calculation resulted in the equivalent energy level of 1.98 eV for HOMO, and 4.48 eV. These values represent the energy gap (Eg) for sensitizer on DSSC. Furthermore, evaluation of electronic transition of iron complex reveals that there is an increase of absorption coverage range, due in particular the blue shift of the conduction band. These characteristics are supporting evidences that the iron-anthocyanin complex is a good candidate for sensitizer of DSSC.

The influence of different seeds solution concentration upon chemical bath deposition process on the morphology of ZnO nanorods

The unique characteristics of zinc oxide (ZnO) nanorods including high surface to volume ratio and fast electron transfer makes this material potentially applicable for various areas such as photovoltaic devices, dye-solar cells, electric field, and biomedical. In this work, the influence of different seed solution concentration on the morphology of ZnO nanorods using chemical bath deposition (CBD) method was investigated. The seed solutions with 3 different concentration of 0.005, 0.025 and 0.05 M were prepared by dissolving 1: 1 equimolar zinc nitrate tetrahydrate (Zn (NO3)2.4H2O, Merck) and hexamethylene tetraamine (C6H12N4 / HMTA, Merck) in water at 0°C for 1 hour. The formation of seed layers was carried-out by spin coating of the precursors on the glass substrate, followed with annealing at 200°C for 5 minutes. Further growth of ZnO nanorods was performed by CBD at 90°C for 3 hours. The morphology of ZnO nanorods was characterized by using field emission scanning electron microscopy (FESEM). The results showed that seeds concentration of 0.005 M formed inhomogeneous nanorods with average diameter of 161 nanometers, meanwhile 0.025 and 0.05 M has successfully formed more homogeneous nanostructures with average diameter of 205 and 427 nm, respectively. On the basis of investigation, it has been confirmed that higher concentration of seed solution provided more suitable formation of ZnO nanorods.

Energy-level engineering of the electron transporting layer for improving open-circuit voltage in dye and perovskite-based solar cells

BaSnO3 is designed as an electron transport layer of high-efficiency perovskite and dye-sensitized solar cells by fine-tuning energy levels through substitution of specific amounts of Sr ions.

Morphology and Electronic Properties of TiO2 Nanotubes Arrays Synthesized by Electrochemical Method

Background: A nano-tubular structure of Titanium dioxide (TiO2) was obtained using an electrochemical process based on the anodization of titanium foil in an organic electrolyte prepared with ethylene glycol (HOCH2CH2OH) containing Ammonium fluorides (NH4F) and ultrapure water under different anodization voltage. The morphological characteristics showed the formation of TiO2 nanotubes with different geometrical parameters. The electronic properties of the TiO2 NTs films were measured by the Mott-Schottky (MS) plots, indicating a positive slope for all graphs implying the n-type semiconductor nature of the TiO2 nanotubes (TiO2 NTs). The donor density (Nd) and the flat band potential (Efb) increases slightly with increase the anodization voltage. Methods: Prior the anodization, the titanium (Ti) foils were cut into square shape (2.25 cm2) with a selected work area of 0.6 cm2. The samples were subjected to a final polishing using a rotating felt pad (01 &µm) impregnated with alumina until a metallic mirror surface was obtained. The Ti foils were degreased by sonication in acetone, methanol and 2-Propanol for 10 minutes respectively, rinsed with ultrapure water and dried in a stream of compressed air. To form a TiO2 NTs, electrochemical anodization process was carried out at room temperature in Ethylene Glycol (EG) solution containing 0.3 wt% Ammonium fluorides (NH4F) and 2wt % ultrapure water for three (03) hours at different anodization voltage (20, 40 and 60V). A two-electrode cell was used for all the anodization measurements, with a platinum plate as the counter electrode, separated from the working electrode (titanium foil) by 1.5 cm. Immediately after anodization, the samples were soaked in ultrapure water to remove residual electrolyte for 10 minutes and then dried in an oven at 50 °C for 10 minutes. Results: TiO2 NTs grown from anodization of Ti foil in fluoride EG solution for 3h by varying the anodization voltage. The micrographic analysis shows a strong influence of the anodizing voltage on the morphology and geometrical parameters of the TiO2 NTs. Non homogenous NTs morphology was observed at 20 V with the presence of corrugations along the walls of the tubes. A perfect and regular nanotublar structure with smooth’s walls tubes was obtained at an anodization voltage of 60V. Moreover, the increase of anodization voltage leads to an increase in both the diameter and the length of tubes. In fact, the inner diameter and the length of the tubes (Di and L) values increase with increasing potential, being around (39 nm and 2 &µm) respectively at 20 V and (106 nm and 16,1 &µm) at 60 V. The measured electronic properties of TiO2 NTs indicating the n type semiconducting nature. It is remarkable that the donor density Nd increases toward higher values by increasing the anodizing voltage until 40V. However, for an anodization at 60V, the Nd has a small decrease value (7, 03 * 1019 cm-3) indicating a diminution of defects present in the material. Also, by increasing the anodizing voltage, Efb takes increasingly more positive values. In fact, the Efb values are – 0.12, 0.05 and 0.15 V for films prepared at 20, 40 and 60 V respectively. Therefore, this behavior can be attributed to a displacement of the Fermi level toward the conduction band edge which leads to a larger band bending at the interface. Conclusion: By varying the anodization voltage, titanium dioxide nanotubes (TiO2 NTs) were grown using electrochemical anodization of titanium foil in fluoride ethylene glycol solution for 3 hours. The morphology of the TiO2 NTs obtained was considerably affected; the anodizing potential determines the migration of ions in electrolyte during anodization process and simultaneously the tube diameter. An average small a nanotube diameter around 39 nm was obtained for 20V corresponding to 106 nm average diameter for TiO2 NTs structure synthesized at 60V. Furthermore, the semiconductor properties of the TiO2 NTs films have also been modified with increased values while increasing the anodization voltage. This behavior was attributed that the TiO2 NTs structure is more disordered, having much more defects provide abundant local donor energy levels which increases conductivity and decrease the probability of recombination of electrons and holes in these films, that can be integrated as active layer in the solar cells, in particular the Gratzel cells.

Polyaniline (PANI)/reduced graphene oxide (rGO) composite as a counter electrode for dye solar cells.

Polyaniline (PANI)-reduced graphene oxide (rGO) based transparent counter electrodes have been fabricated for dye sensitized solar cells as an alternative to the expensive platinum (Pt) counter electrodes. Here, the graphene oxide (GO) added during the polymerization of PANI will subsequently reduce to rGO. The concentration of graphene oxide (GO) was varied in PANI matrix to optimize the performance of dye solar cell (DSC). With 1% GO addition in PANI, 9.68% current density was increased, consequently, 13.9% photocurrent density was found to be increased as compared to pure PANI. Electrochemical impedance spectroscopy (EIS) disclosed that the incorporation of 1% GO in PANI caused the double-layer capacitance to increase by 10 times compared to pure PANI. This implies that graphene is capable of enhancing the specific surface area and catalytic capacity of PANI. Optical transparency of PANI-1% GO counter electrode was found to be ∼67% between the wavelengths of 500 to 600 nm. Such transparency enables the construction of bifacial DSCs. Although the photo conversion efficiency (PCE) of DSC with PANI-1% GO counter electrode is still not comparable to the one with Pt counter electrode but it is sufficient to be considered as the replacement as it exhibits good photovoltaic performance and optical characteristics together with an exceptionally low cost material.

Co-sensitization aided efficiency enhancement in betanin\u2013chlorophyll solar cell

Dye-sensitized solar cells (DSSCs) are a promising third-generation photovoltaic cell technology whose advantages are low-cost fabrication, reduced energy payback time, better performance under diffuse light conditions and flexibility. Typically DSSCs employ toxic dyes such as metal-based porphyrins requiring complex synthesis. In contrast, natural pigments are environmentally and economically superior to synthetic dyes. However, narrow absorption spectra of natural pigments result in low efficiencies of the solar cells. Hence, co-sensitizing pigments with complementary absorption spectra, which increases the absorption band, is an attractive pathway to enhance the efficiency. In this paper, we report the performance of betanin–chlorophyll co-sensitized solar cell using betanin (λmax = 535 nm) and chlorophyll-a (λmax = 435 nm, 668 nm), natural pigments having complementary absorption spectra. Density functional theory simulations were performed to verify that the lowest unoccupied molecular orbital and the highest occupied molecular orbital levels of the dye molecules, are aligned appropriately with that of TiO2 and the redox electrolyte, respectively, which is necessary for optimal device performance. Electrochemical impedance spectroscopic studies were performed to determine parameters corresponding to the charge transfer processes in the dye solar cells. Individual and co-sensitized solar cells were fabricated and the co-sensitized solar cell demonstrated a higher efficiency of 0.601% compared to efficiencies of 0.562% and 0.047% shown by betanin and chlorophyll solar cells, respectively.

Fabrication and Characterization of Dye-Sensitized Solar Cell using Chemically Grown ZnS Nanoparticles

In this work, we have fabricated dye-sensitized solar cell (DSSC) based on chemically grown ZnS nanoparticles with three different source of dye namely Gerbera jamesonii, Rosa indica and Acalypha wilkesiana leaves extract. Anthocyanin, a kind of natural dye found in the leaves of plants and flowers was used as photosensitizers in preparing dye-sensitized solar cell. The optical properties of anthocyanin present in three dyes were also studied. Morphological properties have been studied by atomic force microscopy on ZnS film as well as on ZnS film with dye. The current-voltage characteristics of the dye-sensitized solar cell had been studied in light condition. The DSSC is characterized by the measurement of open circuit voltage, short circuit current density; efficiency and fill factor. The efficiency of three dye solar cell is different and it is maximum for Acalypha wilkesiana leaves extract dye.

Optical absorption spectroscopy of the blackberry dye applied in solar cell sensitizers and gamma radiation effects.‎

This paper is a part of natural dye solar cell project. The dye extracted from blackberry fruit is successfully used in the ‎fabrication of natural dye sensitized solar cells (NDSSC). Blackberry dye extract is showed to contain anthocyanins which is ‎an excellent light harvesting pigment needed for the generation of charge carriers for the production of electricity. A strong ‎absorbance in the green region (520 nm) is observed for blackberry dye at pH 1. The color intensity of the blackberry dye is ‎decreased with the gamma dose up to 5 kGy and then saturation started. The high absorption range is found in blackberry ‎dye 360-750 nm. The absorption band edge value of the natural dye solutions of the blackberry is found 1.97 eV from the ‎maximum peak position (at wavelength 630 nm). Tauc gap (Eg) of the blackberry dye is found 1.96 eV for direct transition. ‎It is observed that the gamma dose up to 7 kGy showed no significant effect on both absorption edge and Tauc gap of ‎blackberry dye. The particles sizes range of the blackberry dye form the blackness pigment is found to 0.6-3.0 and 0.4-1.0 ‎microns in diameter before and after gamma radiation. The optimum conditions of NDSSC based on this study of Blackberry ‎dye are found that VOC=0.5, JSC =0.7 mA.cm-1, FF=0.5, and η %=0.2.‎

Fatigue Assessment by Blink Detected with Attachable Optical Sensors of Dye-Sensitized Photovoltaic Cells.

This paper demonstrates fatigue assessment based on eye blinks that are detected by dye-sensitized photovoltaic cells. In particular, the sensors were attached to the temple of eyeglasses and positioned at the lateral side of the eye. They are wearable, did not majorly disturb the user’s eyesight, and detected the position of the eyelid or the eye state. The optimal location of the sensor was experimentally investigated by evaluating the detection accuracy of blinks. We conducted fatigue assessment experiments using the developed wearable system, or smart glasses. Several parameters, including the frequency, duration, and velocity of eye blinks, were extracted as fatigue indices. Successful fatigue assessment by the proposed system will be of great benefit for maximizing performance and maintenance of physical/mental health.

Improved Performance of Natural Dye for Eco-friendly Solar Cell Application using SnO2 Nanoparticles by Chemical Precipitation Method

Natural dye-sensitized solar cells (NDSSCs) have gained important interest in the field of solar energy owing to their low production cost, simple fabrication and good efficiency. In the present study, SnO 2 nanoparticles were prepared by chemical precipitation method. The photoanode is fabricated using doctor-blade technique. In this paper, the dye molecules absorb light and make excited electrons the technique adopted, which in revolve create current in the output terminals of the cell. Graphite coated glass was used as the counter electrode. The prepared nanoparticles are characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and UV-Visible spectroscopy. XRD analysis confirms the structure of tetragonal structure with rutile phase, and crystallite sizes 20-30 nm. Curcuma longa dye extract used as photosensitizer. FTIR results show the M-O (Sn-O) bond with no other distinct impurities from the chemical reactions that were used for SnO 2 preparation. Finally, photocurrent-voltaic characterization of nano-crystaline natural dye solar cell using I-V studies. It was found that the levels of short-circuit current (Jsc), open-circuit voltage (Voc), fill factor (FF) and overall conversion efficiency (η) of Curcuma longa dye extract. Further suggestions to improve the efficiency of NDSSC are discussed.

Testing dye‐sensitized solar cells in harsh northern outdoor conditions

AbstractHere, we report on the behavior of dye solar cells in real‐life weather conditions from a northern outdoor test covering for the first time cell performance measurements in harsh conditions with varying weather from mildly warm conditions to freezing and snowy. The effect of different weather conditions on the cell performance is quantitatively investigated by using correlations coefficients of weather parameters to cell performance. No degradation was observed during the frosty period, but instead during the warmer, rainy periods with high moisture levels. Nevertheless, after 6 weeks of outdoor testing in varying harsh conditions, the cells maintained on average 88% of their initial efficiency. Tracking the cell performance during the aging showed that the test cells generated roughly as much current at subzero temperatures as at warmer temperatures. Investigations of the degradation reactions revealed that while photoelectrode degradation was the main cause of degradation during this test, the loss of charge carriers, which had only a minor effect on performance during the test, would likely become a major degradation factor during the next 1000 h of testing. Furthermore, the test showed that the cells even doubled their efficiency in low light intensity conditions compared with the standard reporting conditions. Thus, the overall conversion efficiency during the whole experiment reached up to 50% higher values compared with the results in standard testing conditions.

Recent progress in flexible dye solar cells

Flexible dye‐sensitized solar cells are an intriguing photovoltaic technology, especially from the point of view of integration of photovoltaics into everyday objects, owing to these solar cells conforming easily to different nonplanar geometries and low‐intensity lighting conditions. However, the commercialization of these devices has not yet fully taken off due to few persisting gaps in the optimization of employed materials and processes. Herein, we focus on the recent progress on flexible dye sensitized solar cells, and how obstacles to larger‐scale production have been removed. There have been major advancements in diverse roll‐to‐roll compatible preparation methods of various cell layers, as well as in understanding the corrosion of metal electrodes in liquid electrolyte. We also pinpoint the remaining challenges for full commercialization of these technologies, one of which is reaching long‐term stability in which case sealing of the flexible device plays a major role. Furthermore, environmental considerations such as the life cycle assessment and the use of more sustainable materials in solar cell preparation are discussed.This article is categorized under: Energy Research & Innovation > Science and Materials Photovoltaics > Science and Materials

Influence of intermolecular interactions on the properties of carbon nanotubes

This study is aiming at theoretical and experimental confirmations of the deposition of oligothiophene dyes (OT) on structurally and chemically diverse surfaces of carbon materials, especially carbon nanotubes (CNTs). This study is a contribution to the wide search and design of novel hybrid materials for light-sensitive (dye solar cells) and light-emitting (LEDs) structures. The obtained materials containing OTs embedded in the pores of a carbon matrix were analysed by means of microscopic and spectroscopic techniques as well as low-temperature adsorption of nitrogen, together with an investigation of the surface area by the BET method. Confocal microscopy was employed to confirm the immobilization of oligomers on the surface of CNTs. Raman spectra, XRD and HTEM microscopies allowed to judge the quality of the carbonaceous material and to compare the test material before and after the introduction of OT. Additionally, the elemental content and elemental surface species were determined by means of XPS and combustion elemental analyses. The explanation of thiophene; 2,2 $$^\prime $$ :5 $$^\prime $$ ,2 $${^{\prime \prime }}$$ -terthiophene and $$\alpha $$ -sexithiophene molecular interactions with single wall armchair CNTs was supported by theoretical calculations. In computational investigations, CNTs were modelled by tubules of different sizes, lengths and hydrogenated open ends.

3G1-E2 身近な材料を用いた色素増感太陽電池で手作り電子メロディを鳴らす実験教材の開発(教材開発(3),一般研究,次世代の科学力を育てる : 社会とのグラウンディングを実現するために)

3G1-E2 身近な材料を用いた色素増感太陽電池で手作り電子メロディを鳴らす実験教材の開発(教材開発(3),一般研究,次世代の科学力を育てる : 社会とのグラウンディングを実現するために)

The state of external circuit affects the stability of dye-sensitized solar cells

We found that the electrical state in which dye solar cells operate affect their ageing. Three states were analysed: open-circuit (OC), short circuit (SC), and under maximum power point (MPP) / load. OC and SC are more or less atypical states, which are relevant while storing cells or in the event of malfunction, whereas the MPP/load corresponds to real life operation of the cells. Our results indicate that keeping the cells at OC or near the MPP lead to practically identical stability, whilst the cells at SC degraded much faster in a 1000 h light soaking test. The underlying cause for the degradation of all the cells was the loss of tri-iodide (i.e. limiting charge carriers) in the electrolyte. While the degradation mechanism appears to be the same, the loss rate of tri-iodide was about five times faster with SC than with OC and MPP cells. In the SC cells, the loss of tri-iodide decreased both the short-circuit current and fill factor resulting in a 36% efficiency loss by the end of the test. In contrast, the efficiency of the OC and load cells remained quite stable throughout the test. Since OC is the most commonly used state in aging tests, it is good news for ageing studies that the real life MPP state and the OC state yield roughly similar results. The identification of the degradation pathway, the loss of charge carriers, and the related degradation rate were used to estimate the remaining lifetime of cells which did not degrade during the 1000 h test. Based on the degradation rate related to the charge carrier loss, full degradation of the OC and MPP cells is expected in approximately 3000 h of operational time.

Critical analysis on the quality of stability studies of perovskite and dye solar cells

Urgent deficiencies in the aging tests of perovskite and dye solar cells are identified and improved methods are proposed in this work.

Visible and near-infrared organic photosensitizers comprising isoindigo derivatives as chromophores: synthesis, optoelectronic properties and factors limiting their efficiency in dye solar cells

We developed organic photosensitizers based on isoindigo derivatives that strongly absorb up to the near-IR for application in DSSCs.

A detailed evaluation of charge recombination dynamics in dye solar cells based on starburst triphenylamine dyes

Molecularly engineered starburst triphenylamine dyes, endowed with better hole separation and structural effects preventing recombination leading towards improved efficiencies.