Efficiency Of DSSCs Research Articles

Effect of Tungsten Doping on the Properties of Titanium Dioxide Dye-Sensitized Solar Cells

Tungsten-doped TiO2 thin films were prepared by sol–gel method on fluorine-doped tin oxide-coated substrates as working electrodes of dye-sensitized solar cells. The influences of different W doping (0, 2, 4, 6, and 8 at%) on the microstructure, optical, and photovoltaic properties of the W-TiO2 thin-film DSSCs were studied by the measurement of X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET) analysis, and electrochemical impedance spectroscopy (EIS). An optimal DSSCs performance was observed with a 6 at% W-doped TiO2 thin film, resulting in a Voc of 0.68 V, a Jsc of 20.2 mA/cm2, an FF of 68.6%, and an efficiency (η) of 9.42%. The efficiency of DSSCs with 6 at% W-doped TiO2 photoanode improved by 75%. This is because the 6 at% W-doped TiO2 thin film increases the specific surface area and electron transfer rate.

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.

Polyvinylidene fluoride‐co‐hexafluoropropylene polymer gel electrolyte‐enabled dye‐sensitized solar cell for sustainable energy

AbstractDeveloped specifically to address leakage and stability concerns inherent in liquid electrolytes, this study presents a significant advancement in polymer gel electrolyte (PGE) formulation by combining potassium iodide (KI), ammonium iodide (AI) salts, and polyvinylidene fluoride‐co‐hexafluoropropylene (PVDF‐co‐HFP) as a host polymer. The tape casting method was employed to deposit the standard TiO2 paste as the photoanode and platinum paste as the counter electrode. N3 dye was incorporated, and PVDF‐co‐HFP was used as the PGE between the electrodes. The conductivity of PGE was measured by using a digitized conductivity meter. The quasi solid‐state solar cell (QS‐DSSC) assembled using single salts (KI, and AI), and mixed cations PGE was examined via photocurrent–voltage characteristics, and electrochemical impedance spectroscopy. The augmented ionic conductivity directly influences the efficiency of DSSCs. Notably, incorporating a mixed salt (KI + AI) within the PGE enhances ionic conductivity compared to single‐salt‐based counterparts. The resultant DSSCs using mixed salt PGE exhibit a Voc of 600 mV, Jsc of 1.01 mA/cm2, FF of 0.6089, and an efficiency of 0.369%, outperforming those using KI or AI. This highlights the perceptible advantages of employing this innovative electrolyte composition to enhance solar cell performance.

Solvent selection for anthrocyanin dye extraction from Kigelia Africana and Hibiscus sabdariffa for dye sensitized solar cells

The main flavonoid pigment in the petals of Kigelia Africana and the calyx of Hibiscus sabdariffa is anthocyanin, responsible for the vibrant red, maroon, and purple hues in flowers. This pigment can modulate incident light on flowers, prompting its selection for detailed investigation. TiO2 nanostructures were synthesized using a one-step hydrothermal method, revealing the formation of nanorods and a single-phase rutile structure through FESEM and XRD analyses, respectively. The study aimed to assess the impact of various solvents on the extraction of natural dyes, which were subsequently sensitized on TiO2 photoanodes for DSSC applications. Four solvents-water, water with HCl, ethanol, and citric acid were employed to extract natural dyes from Kigelia Africana's petals and Hibiscus sabdariffa's calyx. Notably, dyes extracted with citric acid demonstrated promising results. The conversion efficiency of DSSCs fabricated with Kigelia Africana dye and Hibiscus sabdariffa dye, extracted using citric acid as the solvent, was found to be 0.87 % and 0.92 %, respectively. The implications of these findings are discussed.

Mesoporous Ti-substituted NiO nanosheets as an efficient electrocatalyst for triiodide reduction in dye-sensitized solar cells

In this work, a novel two-dimensional hexagonal mesoporous nickel oxide (2D-HM NiO) and titanium substituted NiO (Ti (1, 3, 5, 7 and 9 mol%)-NiO) nanosheets (NSs) are synthesized via a one-step hydrothermal method. The as-prepared 2D-HM NiO and Ti (1–9%)-NiO NSs are used to fabricate cost-effective counter electrodes (CEs) for DSSCs. The DSSCs device made with NiO and 1% of Ti-substituted NiO (1-TNO) CEs show excellent electrochemical properties and photovoltaic performance. The 100 consecutive cycles of cyclic voltammetry (CV) shows that NiO and 1-TNO CEs have high chemical stability towards I−/I3− redox mediator as compared with Pt CE. For the first time, the power conversion efficiency (PCE) of DSSCs with NiO-based CE reached up to 4.08% whereas 1-TNO CE a PCE slightly increased up to 4.12% which is relatively closer to Pt-based CE (5.34%) under identical working conditions. The high performance of NiO and 1-TNO CEs can be attributed to the large number of electrocatalytic active sites and fast ion diffusion, which is due to the high specific surface area of the 2D nanosheet structure with mesoporous nature.

Great enhancement in power conversion efficiency of DSSCs with Ni0.85Se nanoparticles as counter electrode in contrast to matrix nickel particles

Pure nickel nanoparticles with diameter around 100 nm were prepared with a moderate hydrothermal method. The matrix was then selenized into Ni[Formula: see text]Se particles in a Se vapor without any damage to their original morphologies. The as-prepared N[Formula: see text]Se and Ni nanoparticles were then used as counter electrodes (CEs) in dye-sensitized solar cells. It was found that the performance of the cell with Ni[Formula: see text]Se as counter electrode is enhanced by nearly two times in contrast to the one with Ni as CEs. This provides a new method to fabricate optional counter electrode for Pt.

Enhanced efficiency of DSSCs by co-sensitizing dyes with complementary absorption spectra

In order to understand the mechanism of molecular improvement by dye co-sensitization at the microscale, a co-sensitized molecular system is simulated using density functional theory and time-dependent density functional theory. The single molecules AJ502 and TZ101 are first evaluated globally, with AJ502 having better spectral response performance and higher light absorption efficiency. The AJ502 molecule has a strong electron accept ability and intramolecular charge transfer phenomenon. These factors make the short circuit current density and photoelectric conversion efficiency of AJ502 have a very prominent performance. At the same time, the co-sensitization properties of AJ502 and TZ101 are investigated, finding that the overall molar extinction coefficient and charge transfer phenomenon of the co-sensitized system are enhanced. Most importantly, a detailed comparison of the effects of the two co-sensitized conformations on dye-sensitized solar cell devices shows that the H-H conformation is the most advantageous due to its more robust structure, pronounced red shift in the absorption spectrum and larger amount of intermolecular charge transfer.

Calcium-doped TiO2 microspheres and near-infrared carbazole-based sensitizer for efficient co-sensitized dye-sensitized solar cell

Here, we synthesized metal-free organic dye (CCPICPB) with two carbazole donor groups and two anchoring groups that exhibit a panchromatic absorption in the near-infrared range of up to 750 nm. To study the photophysical properties of synthesized CCPICPB dye, the UV–Vis and cyclic voltammetric experiments were studied and the obtained results were validated with theoretical simulation studies. After that, the solvothermal approach is used to synthesize pristine anatase and calcium (Ca)-doped TiO2 microspheres with a smooth morphology. These microstructures are examined in depth using XRD, electron microscopy and electrochemical analysis methods. On TiO2 and Ca-doped TiO2 photoanode materials, we first evaluated the performance of CCPICPB dye. Upon our optimized experimental condition, the 3% Ca-TiO2 photoanode-based device exhibits an efficiency of 4.04%, which is greater than that of the pristine TiO2 photoanode-based device (2.93%). Because of the quicker electron transport in the Ca-TiO2 film, the short-circuit current density and efficiency of DSSCs were improved. Moreover, when the CCPICPB dye was used as a co-sensitizer with the common Ru(II) dye (Z907), interestingly it showed the highest efficiency (6.11%) when compared with Z907 alone (5.12%). This improved efficiency of the co-sensitized device resulted from greater VOC conjugated with improved JSC. The JSC was improved because CCPICB dye could compensate for the photocurrent loss caused by redox electrolyte while the VOC was improved because electron recombination was inhibited under the co-sensitization conditions.Graphical abstract

Design of experiments optimization of fluorine-doped tin oxide films prepared by spray pyrolysis for photovoltaic applications

Transparent conducting oxides (TCOs) have witnessed an ever-expanding use in our lives through many optoelectronic applications, namely photovoltaic (PV) devices. Indium-tin oxide (ITO) is the most used and studied TCO, but it lacks thermal and chemical stability and indium is a scarce and toxic element. Fluorine-doped tin oxide (FTO) emerged as the most promising alternative to ITO, presenting better thermal and chemical stability. Among the numerous techniques for depositing FTO thin films over glass substrates, spray pyrolysis is the simplest and most economical, with great potential for upscaling. However, the relative importance of the experimental variables that influence the optoelectronic properties remains barely addressed. Following this premise, the present work aimed at optimizing the deposition of FTO films on soda lime glass (SLG) substrates by spray pyrolysis following a Design of Experiments (DoE) methodology. The optoelectronic properties of FTO-SLG substrates was evaluated based on their optical transmittance and sheet resistance, both combined in a figure of merit (FoM) tailored for PV applications. It was concluded that the volume of sprayed solution and the fluorine/tin ratio in the precursor have the greatest influence in the FoM, being the optimal deposition conditions a sprayed volume of 60.8 ml and a [F]/[Sn] ratio of 0.45. FTO-SLG substrates prepared with these conditions achieved a FoM of 0.680 Ω□−1/10, corresponding to a sheet resistance of 3.40 Ω□ and a transmittance equivalent to 77% of the maximum current generated in the considered spectrum. The improved FoM was validated in dye-sensitized and perovskite solar cells (DSSCs and PSCs, respectively), assembled with in-house optimized and commercial substrates. The efficiency of DSSCs was improved by 8.9% (relative), whereas PSCs achieved a light-to-power efficiency of 17% (absolute), corresponding to an improvement of 4.7% (relative).

Effect of Different Counter Electrodes on Power Conversion Efficiency of DSSCs

Effect of Different Counter Electrodes on Power Conversion Efficiency of DSSCs

DFT exploration to tune the silyl group as anchoring unit on the performance of dye-sensitized solar cells: an approach to suppress dye leaching from semiconductor surface.

In this work, we report the lower stability of dyes containing cyanoacrylic acid anchoring group on semiconductor TiO2 surface compared to the corresponding silyl unit in dye-sensitized solar cell. Density functional theory (DFT) calculations have been performed with simple donor (N,N diphenylamine) and π-conjugated spacers, with silyl anchoring groups to examine the efficiency of DSSCs. The calculated results in CAM-B3LYP/6-31G(d)/CPCM(THF) reveal that the cyanoacrylic acid anchoring group would have weaker coordination on semiconductor TiO2 surface compared to the silyl anchoring group on the same surface. The designed dyes 1-7 exhibit comparable or in cases superior optical properties than that of the reference dye molecule with cyanoacrylic acid as an anchoring group. All designed dyes have lower ΔGrejection values implying efficient and faster electron recombination between the dye and electrolyte. The electron transition coefficient for these dyes is higher enough (~72-87%) suggesting successful electron propagation from dye to the semiconductor. The electron-donating methyl and ethyl groups show lower ΔGrejection values than the commonly studied -OEt substitution with the silyl anchoring group. The extended π conjugation for better electronic propagation and higher λmax values have been achieved with simple ethylene and butadiene units in the dye molecules. Dye 7 with butadiene as π-spacer unit shows superior oscillatory strength (f) of 2.19 and light-harvesting efficiency (LHE) of 0.99 than the other studied dyes and reference dye with carboxylic anchoring group (TA-ST-CA). The lowest ΔGrejection value (0.53 eV) of dye 7 suggests better electronic recombination than all the other dyes studied here. Transition Density matrix and PDOS calculations with the representative dye 7 suggest a good electronic propagation from the dye to the semiconductor. The incorporation of a highly π-conjugated spacer 4,8-di(thiophen-2-yl)-1H,5H-benzo[1,2-c:4,5-c']bis([1,2,5]thiadiazole) in dye 7 (7-BBT) showed remarkable enhancement in the absorption maxima ~800 nm corresponds to the UV-vis and NIR regions. The DFT calculated results shed light on designing new DSSCs with silyl anchoring groups for enhanced stability and superior efficiency.

Fabrication of dye-sensitised solar cells using four natural sensitisers of ZnO nanoparticle at different pH values

In this paper, DSSCs were fabricated using the ZnO compound in three different pH values. In each pH values using four natural dyes, in total 12 DSSCs were fabricated. First of its kind, pH variation is used as a photo anode in DSSC fabrication. For the ZnO nanoparticles, the structural analysis is carried out with XRD, FESEM, and EDAX. Optical studies (UV-visible and FTIR) were recorded for extracted natural dyes. The typical J-V curves for solar cells under AM 1.5 using a density of power of 100 mW/cm2 were measured. J-V characterisation study was performed to study the efficiency of the prepared cells. To our knowledge, the efficiency of DSSCs extracted from four dyes with photoanode by varying pH has been reported for the first time. As a result of prepared solar cells, the solar cell derived from the Terminalia leaf at pH-9 showed the higher efficiency of 0.60% compared to other pH values of 3 and 6.

The effect of secondary dopants on screen‐printed PEDOT:PSS counter‐electrodes for dye‐sensitized solar cells

AbstractDye‐sensitized solar cells (DSSCs) gained great attention thanks to high conversion efficiency at ambient indoor light and the possibility of low‐cost and eco‐friendly fabrication by printing techniques (screen‐printing) on different flexible or rigid substrates. These properties predetermine the use of DSSCs in current and future Internet of Things portable and wearable applications. However, one of the main problems of the standard DSSC structure lies in an expensive and unstable Pt counter‐electrode (CE) in the liquid electrolyte. Printable conducting polymers, in particular doped poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) are the promising alternative. This work presents the preparation of the Pt‐free counter‐electrodes by screen‐printing the water‐based PEDOT:PSS inks and their optimization by adding secondary dopants, that is, ethylene glycol, polyethylene glycol, and dimethyl sulfoxide. Selected secondary dopants influenced the rheological and structural properties, conductivity, and electrochemical behavior of PEDOT:PSS inks and screen‐printed PEDOT:PSS CE. The addition of dopants led to the decreased surface tension of PEDOT:PSS inks, with a subsequent positive effect on better wettability of FTO substrates. The lowest sheet resistance 138 Ω/sq, the highest conductivity 91 S/cm, best electrochemical activity towards triiodide reduction and the highest efficiency of DSSCs was evaluated for screen‐printed PEDOT:PSS CEs doped with 6 wt% of ethylene glycol.

Transition divalent metal substitution in chalcopyrite CuInSe2 (In = Co, Ni, and Mn) counter electrode for dye-sensitized solar cell applications

The synthesis of low-cost and high electrochemical activity to regenerate electrolyte and to enhance the efficiency (counter electrodes (CE)) is of paramount importance for the DSSCs. To achieve the maximum power conversion efficiency of DSSCs with the low-cost counter electrode (CE), Cu– (In, Co, Ni, Mn)–Se2 has prepared by hydrothermal method. The structural and chemical composition of Cu– (In, Co, Ni, Mn)–Se2 was confirmed by XRD and XPS analysis. The charge transfer resistance of CuInSe2 (CIS), CuCoSe2 (CCS), CuNiSe2 (CNS), and CuMnSe2 (CMS) were 5.60, 11.50, 1.40, and 5.60 Ω (CNS < CIS < CMS < CCS), where CNS showed minimum charge transfer resistance, owing to the intrinsic electrochemical and electrical properties of Ni. The CNS (4.16 %) showed better photovoltaic efficiency which was 1.51 times higher than the CIS CE (2.65) based DSSCs.

Fabrication of dye-sensitized solar cells with ZnO nanorods as photoanode and natural dye extract as sensitizer

Highly oriented zinc oxide nanorods (ZnO NRs) have been grown on ITO substrates at various growth times using hydrothermal method. The necessary ZnO seed layers on ITO have been deposited using spray pyrolysis. Both the methods have been successfully applied to prepare efficient ZnO NRs-based photoanodes for DSSCs. FESEM images revealed the vertical growth of ZnO NRs from the substrates with a length and diameter ranges of 1.2–1.5 μm and 80–120 nm, respectively. The XRD and HRTEM results confirmed the hexagonal structure with preferential orientation (c-axis) of ZnO NRs. The high optical transmittance (90%) was observed in the visible region for the ZnO NRs grown for 9 h. A decrease in optical bandgap was noticed with the increase of growth times. The natural dye extract absorbed in to the ZnO NRs exhibited a broad absorption peak in UV–Vis spectra analysis. The power conversion efficiency of DSSCs prepared with ZnO NRs (9 h) as photoanode showed better performance compared to other growth times.

Comparative study of the morphological and optical properties of RE3+ (=ND3+, DY3+) doped TiO2: A pursuit for suitable anode material for DSSCs

Nano scaled trivalent Rare-earth Elements (RE3+ = Nd3+ and Dy3+) doped TiO2 anode materials were synthesized by hydrothermal method and characterized to analyze the morphological and optical properties. Having N719 as the dye and Platinum as counter electrode, the solar cells were fabricated to harness the solar energy. The reduction in bandgap and the enhanced efficiency of DSSCs in the TiO2-dye-electrolyte system were analyzed. Nd3+ doped TiO2 exhibits the desired results and superior efficiency than the pure and Dy3+ doped TiO2. Thus comparing the materials’ morphological and optical properties as well as the solar cell efficiency, Nd3+ doped TiO2 proved to be an improved anode material for the fabrication of DSSCs.

The influence of the shape and configuration of sensitizer molecules on the efficiency of DSSCs: a theoretical insight.

The sensitizer is an active component of dye sensitized solar cell (DSSC) technology, which is highly influential for the performance of DSSCs. The present study attempts to investigate the relationship between the shape of the sensitizer molecule and efficiency of DSSCs. Specifically, 17 different structures were investigated, and classified into four categories based on the shape of the dye molecule, namely L-shaped (linear), V-shaped, X-shaped and Y-shaped, and into two different categories based on the donor moiety. The five of studied structures contained a triphenylamine (TPA) donor moiety, and twelve structures contained carbazole (CAR) donor moiety. Parameters related to the performance of DSSCs such as absorption spectra, intramolecular charge transfer indices, frontier molecular orbitals, light harvesting efficiency, excited-state lifetime, exciton binding energy, electrostatic potential, charge transfer and electron injection ability were studied using results obtained from electronic structure calculations. The analysis of these various parameters showed that the linear-shaped and V-shaped sensitizers possess better photon absorption ability, and the V-shaped structure is best suited shape for applications in high performance DSSCs.

Boosting the photoelectric conversion efficiency of DSSCs through graphene quantum dots: insights from theoretical study

The influence of different linkage types between sensitizer and GQD on the photoelectric performance of DSSCs were comprehensively investigated from theoretical perspective.

In-depth understanding of the energy loss and efficiency limit of dye-sensitized solar cells under outdoor and indoor conditions

This perspective thoroughly explores the energy loss factors in DSSCs and estimates the feasible efficiency of DSSCs under outdoor and indoor conditions, and compares it with the SQ limit of an ideal solar cell.

Influence of RhB dye concentration on ZnS nanoflowers decorated TiO2 photoanode in dye sensitized solar cell

Abstract TiO2 nanoparticles were successfully synthesized and used in the active layer of photoanode. The active layer of photoanode was decorated by ZnS nanoflowers in its scattering layer. The photoanodes were subjected to characterisations viz., FESEM, EDXs and XRD. The prepared photoanodes were sensitized with various concentrations of Rhodamine B dye (0.1–0.5 mM). The DSSCs were assembled using dye sensitized photoanodes, low cost Gr-PEDOT:PSS counter electrode and iodide/tri-iodide based electrolyte. The influence of Rhodamine B dye concentration on the performance of DSSCs were analyzed in terms of Voc, Isc, FF and η. The photo conversion efficiency (η) of DSSCs was measured by I-V characteristic measurement under one sun condition (100 mW/cm2) and were found to be 0.98%, 1.07% 1.17%, 1.09% and 0.99% for Cell-1, Cell-2, Cell-3, Cell-4 And Cell-5 respectively.