Efficient Dye-sensitized Solar Cells Research Articles

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

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

Efficient and Stable Z907-Based Dye-Sensitized Solar Cells Enabled by Suppressed Charge Recombination and Photocatalytic Activity

Efficient and Stable Z907-Based Dye-Sensitized Solar Cells Enabled by Suppressed Charge Recombination and Photocatalytic Activity

Surface Loading Dictates Triplet Production via Singlet Fission in Anthradithiophene Sensitized TiO2 Films.

Singlet fission, the process of transforming a singlet excited state into two lower energy triplet excited states, is a promising strategy for improving the efficiency of dye-sensitized solar cells. The difficulty in utilizing singlet fission molecules in this architecture is understanding and controlling the orientation of dyes on mesoporous metal oxide surfaces to maximize triplet production and minimize detrimental deactivation pathways, such as electron injection from the singlet or excimer formation. Here, we varied the concentration of loading solutions of two anthradithiophene dyes derivatized with either one or two carboxylic acid groups for binding to a metal oxide surface and studied their photophysics using ultrafast transient absorption spectroscopy. For the single carboxylic acid case, an increase in dye surface coverage led to an increase in apparent triplet excited-state growth via singlet fission, while the same increase in coverage with two carboxylic acids did not. This study represents a step toward controlling the interactions between molecules at mesoporous interfaces.

Improved Interfacial Electron Dynamics with Block Poly(4-vinylpyridine)-Poly(styrene) Polymers for Efficient and Long-Lasting Dye-Sensitized Solar Cells.

Dye-sensitized solar cells (DSSCs) have recently entered the market for indoor photovoltaics. Fast electron injection from dye to titania, the lifetime of the excited dye, and the suppression of back electron recombination at the photoanode/electrolyte interface are crucial for a high photocurrent conversion efficiency (PCE). This study presents block copolymers of poly(4-vinylpyridine) and poly(styrene)-P4VP67-b-PSt x(x=23;61) as efficient accelerators of electron injection from dye to titania with extended lifetime excited states and long-lasting back electron recombination suppression. P4VP67-b-PSt23 and P4VP67-b-PSt61 rendered devices with PCEs of 10.0 and 9.8%, respectively, under AM 1.5G light; PCEs of 19.4 and 16.4% under 1000 lx LED light were attained. Copolymers provided a stable PCE with the two most popular I3 -/3I- electrolytes based on ACN and 3-methoxypropionitrile solvents; PCE history was tracked in the dark and under 1000 h of continuous light soaking with passive load according to ISOS-D1 and ISOS-L2 aging protocols, respectively. The impact of the polymer molecular structure on electron recombination, charge injection, dye anchoring, light absorption, photocurrent generation, and PCE and the long-term history of photovoltaic metrics are discussed.

Cyanoacetamide co-sensitizers DY-1 and DY-2: Unveiling a promising path to highly efficient photovoltaic devices

This paper presents a novel approach for enhancing the efficiency of dye-sensitized solar cells (DSSCs) through the co-sensitization of cyanoacetamide-based dyes DY-1 and DY-2 with N3 dye. The synthesis and characterization of DY-1 and DY-2 co-sensitizers are described and their potential applications in photovoltaic devices are investigated. The absorption properties of DY-1 and DY-2 were analyzed, revealing their efficient light absorption in the visible range. The co-sensitization of DY-1-2 with N3 dye demonstrated a significant enhancement in photovoltaic efficiency, ranging from 7.40 % to 7.92 %. The reasons for this efficiency enhancement were thoroughly analyzed and attributed to several factors. First, the combination of DY-1-2 with the N3 dye led to a broader light absorption spectrum, enabling more efficient utilization of incident photons. Additionally, co-sensitization facilitates efficient charge separation and injection processes, contributing to improved photocurrent. The acid-base co-sensitization approach further enhances the overall efficiency by maximizing the charge transfer and coverage on the semiconductor surface. This study sheds light on the development of novel sensitizers to enhance the performance of DSSCs, and the findings contribute to the advancement of photovoltaic devices.

Photophysical Properties and Photovoltaic Performance of Sensitizers with a Bipyrimidine Acceptor

Molecular engineering is a crucial strategy for improving the photovoltaic performance of dye-sensitized solar cells (DSSCs). Despite the common use of the donor–π bridge–acceptor architecture in designing sensitizers, the underlying structure–performance relationship remains not fully understood. In this study, we synthesized and characterized three sensitizers: MOTP-Pyc, MOS2P-Pyc, and MOTS2P-Pyc, all featuring a bipyrimidine acceptor. Absorption spectra, cyclic voltammetry, and transient photoluminescence spectra reveal a photo-induced electron transfer (PET) process in the excited sensitizers. Electron spin resonance spectroscopy confirmed the presence of charge-separated states. The varying donor and π-bridge structures among the three sensitizers led to differences in their conjugation effect, influencing light absorption abilities and PET processes and ultimately impacting the photovoltaic performance. Among the synthesized sensitizers, MOTP-Pyc demonstrated a DSSC efficiency of 3.04%. Introducing an additional thienothiophene block into the π-bridge improved the DSSC efficiency to 4.47% for MOTS2P-Pyc. Conversely, replacing the phenyl group with a thienothiophene block reduced DSSC efficiency to 2.14% for MOS2P-Pyc. Given the proton-accepting ability of the bipyrimidine module, we treated the dye-sensitized TiO2 photoanodes with hydroiodic acid (HI), significantly broadening the light absorption range. This treatment greatly enhanced the short-circuit current density of DSSCs owing to the enhanced electron-withdrawing ability of the acceptor. Consequently, the HI-treated MOTS2P-Pyc-based DSSCs achieved the highest power conversion efficiency of 7.12%, comparable to that of the N719 dye at 7.09%. This work reveals the positive role of bipyrimidine in the design of organic sensitizers for DSSC applications.

Enhanced efficiency and stability of dye-sensitized solar cells utilizing FeCo2S4 nanowires as Pt-free counter electrodes

Replacing traditional Pt-based counter electrodes with low-cost and highly stable materials is crucial for the development of commercially viable dye-sensitized solar cells (DSSCs). In this study, we synthesized a ternary Pt-free FeCo2S4 nanowire (NW)-based sulfide electrocatalyst by a three-step solvothermal method. This material was then used as a counter electrode in DSSCs to facilitate the reduction of triiodide species. The formation of FeCo2S4 NW was confirmed by various characterization techniques such as X-ray diffraction, energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. Scanning electron microscopy analysis revealed the structure of the nanowires. Electrochemical studies, which included cyclic voltammetry, electrochemical impedance spectroscopy and Tafel polarization methods, revealed the excellent stability, superior electrocatalytic activity and remarkable kinetics of FeCo2S4 NW in the reduction of triiodide to iodide. Photovoltaic measurements of the fabricated DSSCs yielded a power conversion efficiency (PCE) of 7.88 % for the FeCo2S4-based devices, outperforming the control device made of Pt (PCE=7.45 %). This improvement was primarily due to the increase in short-circuit current density (JSC), thanks to the lower charge transfer resistance (RCT) of FeCo2S4 NW (JSC=15.23 mA/cm2; RCT=5.54 Ω cm2) compared to Pt (JSC=14.12 mA/cm2; RCT=7.07 Ω cm2). In addition, the FeCo2S4 NW-based solar cells exhibited excellent stability and maintained their high PCE value even after 10 days of aging under ambient conditions, while Pt-based DSSCs showed a 3 % decrease from their initial PCE value. This FeCo2S4 NW counter electrode proves to be an excellent alternative to Pt, and the presented results provide valuable insights for the development of cost-effective and highly stable DSSCs.

Carbon dots-Zno/TiO2 ternary nanocomposite as a proficient material to enhance the performance of natural DSSC

A novel sustainable approach for enhancing the efficiency of dye-sensitized solar cells (DSSCs) involves the utilization of a combination of ZnO and carbon dots (CDs) derived from Citrus medica fruit extract, along with microwave-synthesized TiO2 nanoparticles for the preparation of the photoanode. Natural dyes such as Hibiscus rosa-sinensis and Allium Cepa peel are employed as sensitizers to reduce production costs. This co-activation method has demonstrated a significant improvement in the output parameters of the devices. Notably, the photoanode co-activated with ZnO-CD composite (ZnO-CD/TiO2) exhibits the most favorable output parameters when combined with Hibiscus rosa-sinensis dye (open circuit voltage (Voc) = 0.80 V, short circuit current density (Jsc) = 6.62 mA/cm2, fill factor (FF) = 64.20 %, photo conversion efficiency (PCE) = 3.40 %) and Allium Cepa peel dye (Voc = 0.81 V, Jsc = 6.79 mA/cm2, FF = 65.70 %, PCE = 3.61 %). When paired with Allium Cepa dye, the CD modified photoanode (CD/TiO2) offers Voc = 0.73 V, Jsc = 6.64 mA/cm2, FF = 61.27 % and PCE = 2.97 %. Similarly, when combined with Hibiscus rosa-sinensis dye, the output parameters of the CD/TiO2 photoanode are Voc = 0.72 V, Jsc = 6.54 mA/cm2, FF = 64.4 % and PCE = 3.03 %. In comparison to all tested devices, the unmodified photoanode (TiO2) displayed the lowest performance, with parameters such as Voc = 0.59 V, Jsc = 6.45 mA/cm2, FF = 52.5 %, PCE = 2.10 % using Allium Cepa peel dye, and Voc = 0.66 V, Jsc = 6 mA/cm2, FF = 51.60 %, PCE = 2.04 % using Hibiscus rosa-sinensis dye. Furthermore, the co-activation process has been shown to enhance the stability of the devices. While the unmodified photoanodes ceased to operate after eight days, the ZnO-CD composite co-activated photoanodes retained their initial efficiencies up to 61.50 % and 68.53 % with the Allium Cepa peel dye and Hibiscus rosa-sinensis dye, respectively. Therefore, this study underscores the potential of the synthesized composite material in enhancing the performance of natural DSSCs.

Investigation of using amine and acetylamine functional units on naphthalimide dyes for photovoltaic devices

Purpose The purpose of this paper is to introduce four new organic dyes based on naphthalimide for dye-sensitized solar cells (DSSCs). Design/methodology/approach Four new dyes based on naphthalimide with substitutions of amine and acetylamine in position C4 were designed in conjugation with substituted carbazole as donor–acceptor (D-A) architecture. The absorption and emission characteristics of the prepared dyes were evaluated in H2O, DMF and their mixture (DMF:H2O = 1:1). The feasibility of electron transfer in the DSSCs structure and energy levels were evaluated using electrochemical and density functional theory, which confirm the use of dyes in the DSSCs structure. The DSSCs were prepared using an individual strategy and their optical properties were investigated under the light of AM 1.5. Findings The prepared dyes exhibit orange color with strong emission at λem = 530–570 nm due to charge transfer with a positive solvatochromic effect. The efficiency of DSSCs based on Dye1-4 1 is: 3.69%, 3.71%, 4.69% and 4.76%. Therefore, the power efficiency increases by about 29 % in the presence of acetylamine group. Practical implications The design of new structures of organic dyes should be accompanied by the development of optical and electrical properties. In other words, in addition to the continuous production of electrons, efficient dyes must also be resistant to light to increase the life of the device. Social implications Organic dyes play a key role in the production of electrons in the DSSCs structure. The engineering of these structures and the introduction of widely used but low cost types can play an important role in the development of clean energy production. Originality/value The application of organic dyes based on naphthalimide was evaluated in the DSSCs structure and its photovoltaic properties were investigated.

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

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

The influence of metal-free thiophene spacer chain on optoelectronic analysis by TD-DFT method for efficient dye-sensitized solar cells with enhanced non-linear optical activity

The pyrene group in conjugation with the thiophene moiety was used to design new organic molecules for the dye-sensitized solar cells (DSSCs) along with non-linear optical (NLO) properties. Five new thiophene chain conjugation molecules (PTRA-SPn, n = 1–5) were formed based on the (E)-2-(5-oxo-4-((5-(pyren-1-yl)thiophen-2-yl)methylene)-2-thioxothiazolidin-3-yl)acetic acid (PTRA). To comprehend the function of conjugation in varying the optoelectronic characteristics of these compounds, the π-spacer chain has been screened. The techniques of density functional theory (DFT) and time-dependent DFT (TD-DFT) have been used to study the electronic structures, Ultraviolet–Visible (UV–Vis) absorptions, and NLO activities of donor-spacer-acceptor (D-π-A) structures. According to the computed results, PTRA-SP5 exhibits a smaller energy gap (Eg) of 2.11 eV. The maximum UV–Vis spectrum has been found in PTRA-SP5 with a wavelength (λmax) of 532 nm. The reorganizational energy (RE) and dye regeneration (ΔGreg) of PTRA-SP5 are the smallest (λ- = 0.2340 eV, λ+ = 0.2122 eV, ΔGreg = 0.21 eV) compared to other sensitizers. The lowest exciton binding energies (Eb) of PTRA-SP2 (0.06 eV) and PTRA-SP3 (0.06 eV) are the lowest ones. The open circuit photovoltage (eVoc) for PTRA-SP5 (1.10 eV) is the highest. The NLO activity of the dipole moment (μnormal) and first-order hyperpolarizability (β) values of PTRA-SP5 achieve higher values (9.00 Debye and 34.82 × 10−30 esu, respectively). In summary, this work refined the impact of chain π-linkers on the photophysical characteristics of D-π-A spacer derivatives and offered some helpful suggestions to create new organic materials for optoelectronic uses.

Synergistic nanoarchitecture of polythiophene/graphene for enhanced efficiency in dye-sensitized solar cells

In the present study, nanocomposites composed of graphene and polythiophene (PTh) were synthesized through in-situ polymerization techniques. The morphological properties of the composites and the interactions among their constituents were examined utilizing X-ray Diffraction and Scanning Electron Microscopy. The findings suggest that the concentration of graphene within the composites exerts an influence on the performance of solar devices. The solar cell employing a 15% graphene/PTh composite demonstrated superior efficiency at 8.82% compared to its counterparts utilizing 10% (6.62%) and 20% (7.53%) graphene/PTh composites. Furthermore, the efficiency of the graphene/PTh device (8.82%) surpassed that of a platinum (Pt)-based solar cell (8.06%). Thus, graphene/PTh composites exhibit the potential to replace platinum and pave the way for the commercialization of DSSCs.

TiO2/ZnO-based composite thin films coated on FTO surface by screen printing method: increasing dye-sensitized solar cell performance

This study examined the impact of hydrothermally synthesized TiO2:ZnO composite-based nanopowders on the efficiency of dye-sensitized solar cells (DSSCs). Pure TiO2, 3TiO2:1ZnO, 1TiO2:1ZnO, 1TiO2:3ZnO, and pure ZnO thin films were coated on the conductive glass surface by the screen printing method. XRD and SEM were used to examine the thin film’s surface photographs and crystal structure, respectively. XRD analyses confirmed the formation of targeted crystal phases in the structure. It was understood from SEM studies that the TiO2:ZnO composite structure was formed successfully. I-V characterization results showed that the cell combined with the composite 3TiO2:1ZnO electrode had the highest power conversion efficiency (9.9%). In addition, it was determined from EIS analysis that interfacial charge transfer occurred more efficiently in cells with high TiO2 ratio.

The Effect of Conjugated Nitrile Structures as Acceptor Moieties on the Photovoltaic Properties of Dye-Sensitized Solar Cells: DFT and TD-DFT Investigation.

A major challenge in improving the overall efficiency of dye-sensitized solar cells is improving the optoelectronic properties of small molecule acceptors. This work primarily investigated the effects of conjugation in nitriles incorporated as acceptor moieties into a newly designed series of D-A-A dyes. Density functional theory was employed to specifically study how single-double and single-triple conjugation in nitriles alters the optical and electronic properties of these dyes. The Cy-4c dye with a highly conjugated nitrile unit attained the smallest band gap (1.80 eV), even smaller than that of the strong cyanacrylic anchor group (2.07 eV). The dyes lacking conjugation in nitrile groups did not contribute to the LUMO, while LUMOs extended from donors to conjugated nitrile components, facilitating intramolecular charge transfer and causing a strong bind to the film surface. Density of state analysis revealed a considerable impact of conjugated nitrile on the electronic properties of dyes through an effective contribution in the LUMO, exceeding the role of the well-known strong 2,1,3-benzothiadiazole acceptor unit. The excited state properties and the absorption spectra were investigated using time-dependent density functional theory (TD-DFT). Conjugation in the nitrile unit caused the absorption band to broaden, strengthen, and shift toward the near-infrared region. The proposed dyes also showed optimum photovoltaic properties; all dyes possess high light-harvesting efficiency (LHE) values, specifically 96% for the dyes Cy-3b and Cy-4c, which had the most conjugated nitrile moieties. The dyes with higher degrees of conjugation had longer excitation lifetime values, which promote charge transfer by causing steady charge recombination at the interface. These findings may provide new insights into the structure of conjugated nitriles and their function as acceptor moieties in DSSCS, which may lead to the development of extremely effective photosensitizers for solar cells.

Direct Z-scheme heterojunction impregnated MoS2–NiO–CuO nanohybrid for efficient photocatalyst and dye-sensitized solar cell

In this present work, the preparation of ternary MoS2–NiO–CuO nanohybrid by a facile hydrothermal process for photocatalytic and photovoltaic performance is presented. The prepared nanomaterials were confirmed by physio-chemical characterization. The nanosphere morphology was confirmed by electron microscopy techniques for the MoS2–NiO–CuO nanohybrid. The MoS2–NiO–CuO nanohybrid demonstrated enhanced crystal violet (CV) dye photodegradation which increased from 50 to 95% at 80 min; The degradation of methyl orange (MO) dye increased from 56 to 93% at 100 min under UV–visible light irradiation. The trapping experiment was carried out using different solvents for active species and the Z-Scheme photocatalytic mechanism was discussed in detail. Additionally, a batch series of stability experiments were carried out to determine the photostability of materials, and the results suggest that the MoS2–NiO–CuO nanohybrid is more stable even after four continuous cycles of photocatalytic activity. The MoS2–NiO–CuO nanohybrid delivers photoconversion efficiency (4.92%) explored efficacy is 3.8 times higher than the bare MoS2 (1.27%). The overall results indicated that the MoS2–NiO–CuO nanohybrid nanostructure could be a potential candidate to be used to improve photocatalytic performance and DSSC solar cell applications as well.

Exploring charge transfer effects on linear, non‐linear optical, and dye‐sensitized solar cell properties: A DFT and TD‐DFT investigation of carbazole and aniline‐based dyes

AbstractThe efficacy of aniline and carbazole‐based sensitizers used in dye‐sensitized solar cells (DSSCs) is correlated with the trends in density functional theory (DFT) based charge transfer (CT) and non‐linear optical (NLO) properties since both DSSC and NLO properties highly rely on CT properties. The aniline‐based donors showed a higher degree of planarity over carbazole‐based donor sensitizers. This improved planarity in aniline‐based sensitizers is attributed to efficient charge transfer and higher dipole moment. The efficient CT within the sensitizers is confirmed with bond‐length alternation (BLA), bond order alternation (BOA), and quinoid character (QC). A direct correlation of band‐gap (EG) with μ, ω, η, and Γ is witnessed. Time‐dependent DFT (TD‐DFT) results of vertical excitation demonstrated similar trends that are observed practically. Indeed, we observed a direct correlation between α and β and the experimentally observed DSSC efficiency. DFT and TD‐DFT methods, linear, employed for computing the CT and linear and DSSC properties as implemented in Gaussian 09. NLO properties were simulated through single‐point polar calculations. B3LYP and PBE1PBE functionals were used for geometry optimization. The linear and NLO properties were determined in various functionals, that is, global hybrid and range‐separated hybrid functionals. A polarizable continuum model (PCM) was used for solvation studies. To understand the realistic picture of the dye@TiO2 cluster, dye bound on TiO2 clusters were optimized using a LANL2DZ basis set specifically for the Ti atom.

Iron oxide Green synthesized nanoparticles for improved performance in Monolithic Dye Sensitized Solar Cells

In order to improve photovoltaic efficiency in Monolithic Dye-Sensitized Solar Cells (MDSSCs), this study examined the effects of incorporating green produced iron oxide nanoparticles to a nanoporous carbon counter electrode. An extract from the leaves of Ocimum gratissimum was effectively used to synthesize iron oxide nanoparticles. The development of iron oxide nanoparticles was verified by optical absorption in the 350–450 nm range. With an average crystallite size of 47.9 nm, XRD patterns demonstrated the crystalline nature of the Iron oxide nanoparticles. Chemical bonds that may responsible for the nanoparticle production were found using FTIR investigations. An impressive 135.3% boost in efficiency was recorded for cell containing the Iron oxide nanoparticles, according to the MDSSC performance evaluation where DSSC without nanoparticles had a lower solar-to-electric power conversion efficiency of 1.7%, an open circuit voltage of 0.2625 V, a short-circuit current of 0.0723 mA/cm2, and a fill factor of 0.3630. The FeO CEs cell had an open-circuit voltage of 0.4274 V, a short-circuit current of 0.1042 mA/cm2, and a fill factor of 0.46. Their solar-to-electric power conversion efficiency was 4.0%. The potential of incorporating green-synthesised iron oxide nanoparticles into MDSSC counter electrode was shown by their great biocompatibility and even dispersion.

Effect of ball milling time on Sr0.7Sm0.3Fe0.4Co0.6O2.65 perovskites and their application as semiconductor layers in dye-sensitized solar cells

The practical utilization of TiO2 as a semiconductor in dye-sensitized solar cells (DSSCs) has been set back by poor visible light absorption, high charge carrier recombination, and low electrical conductivity, which reduce the power conversion efficiency (PCE) and sustainability of the device. In this respect, perovskites with excellent properties, such as large surface area, good optical properties, high electrical conductivity, and superior electrochemical stability, have recently emerged as promising alternatives capable of overcoming the drawbacks of TiO2. Herein, Sr0.7Sm0.3Fe0.4Co0.6O2.65 (SSFC) perovskites were prepared via the ball milling method at various milling times of 0, 5, and 10 h, and the obtained samples were denoted by SSFC-0, SSCF-5, and SSCF-10, respectively. Increasing the ball milling time led to a significant reduction in nanoparticle size and agglomeration, which, in turn, increased the surface area and electrical conductivity of the samples. As a consequence, the SSFC-10 perovskite exhibited the smallest average particle sizes (18.9 nm) with the largest surface area (61.8 m2 g−1) and minimum defects, which allowed for efficient electron transport, resulting in the best electrical conductivity of 49.8 S cm−1. Ultimately, DSSCs fabricated using SSFC-10 semiconductor layers achieved an optimum PCE of 6.01 %, which is an improvement of 8.67 %, 1.1 %, and 6.56 % for SSFC-0 (3.69 %), SSFC-5 (4.96 %), and TiO2 (5.64 %), respectively. Thus, varying the ball milling time can be used as an effective technique to tailor the physicochemical properties of SSFC to suit desired applications, particularly the fabrication of highly efficient and sustainable DSSC semiconductor layers.

Rational design and elucidation of interfacial dynamics in PMMA/PVDF compatibilized blends through solution blending for stable quasi-solid-state dye-sensitized solar cells

In the photovoltaic market, the widespread adoption of traditional dye-sensitized solar cells (DSSCs) faces obstacles due to inherent stability challenges. The solution to these issues involves replacing liquid electrolytes with quasi-solid electrolytes. In this work, quasi-solid state electrolytes were synthesized by employing a polymer blend and inorganic salt. The polymeric blends, comprising polymethyl methacrylate (PMMA) and polyvinylidene fluoride (PVDF), were meticulously prepared through the solution blending technique. The investigation of blend compatibility, crystallinity, and stability involved analyses through differential scanning calorimetry (DSC), scanning electron microscopy (SEM), X-ray diffraction (XRD), and UV-degradation assessments, respectively. The findings indicated that the concentration of ingredients significantly influenced the compatibility, crystallinity, and stability of the blends. The compatibilized blend was employed in crafting polymer gel electrolytes (PEGs), demonstrating that both the concentration and type of salts significantly influence the ionic conductivity of PEGs. The highest conductivity, reaching 2 mS/cm, was achieved with a mixed salt concentration of 50w%/50w% (NH4I/KI). Subsequently, this electrolyte was incorporated into the fabrication of quasi-solid state DSSC. The results showed that the DSSC with PEG achieved 2.81 % efficiency, while the traditional DSSC had 4.11 % efficiency. Notably, after fifteen days, the efficiency of the traditional DSSC dropped to 0.20 %, while the PEG-based DSSC remained stable (2.58 %).

The Effect of Mixed Dye Composition of Anthocyanin-Chlorophyll on DSSC Efficiency on TiO2/ZnO Semiconductors

The effect of mixed dye composition of anthocyanin-chlorophyll on DSSC efficiency on TiO2/ZnO semiconductors aims to determine the effect of using dye containing anthocyanin-chlorophyll on the absorbance value and work efficiency value of Dye Sensitized Solar Cell (DSSC). The TiO2/ZnO was deposited using the doctor blade method and the dye was made using the maceration method. The counter electrode was made on FTO glass coated by calcined battery carbon with temperature in 450°C. The DSSC assembly was arranged in a sandwich shape. Then electrolyte is dripped in the middle of the DSSC layer. Characterization tests were carried out to determine the dye absorbance value and gap energy value using a UV-Vis spectrophotometer. DSSC efficiency testing uses current and voltage (I-V) characterization. DSSC testing was carried out using a multimeter with a light source from sunlight. The results of UV-Vis characterization showed that the highest absorbance value was obtained for the kale-mangosteen peel dye at a wavelength of 530 nm with an absorbance of 5.234%. The TiO2/ZnO gap energy obtained using the touch plot method is 2.42 eV. The highest efficiency value was obtained from the kale-mangosteen peel dye mixture of 0.0286%. There was an increase in the DSSC efficiency value when the dyes were combined.