High-efficiency Dye-sensitized Solar Cells Research Articles

Enhanced photovoltaic performance of dye sensitized solar cells using cesium bromide modified TiO2 electron transport layer

TiO2 is one of the most widely explored materials as an electron transport layer (ETL) in dye sensitized solar cells (DSSCs) due to its excellent physical and chemical properties. However, recombination at the device's interface slackens the charge carrier movement, adversely affecting their device performance. Rapid extraction of photogenerated charge carriers plays a vital role in developing high efficiency DSSCs. The conduction band alignment of TiO2 ETL and N719 dye light absorber plays a crucial role in charge carrier dynamics of DSSCs. Herein, the band structure of TiO2 ETL is finely tuned by the incorporation of cesium bromide (CsBr). At the optimal concentration (0.4 Wt. %), DSSCs achieved the best power conversion efficiency (PCE) of 9.28 % compared to 7.61 % for pristine TiO2. The modified TiO2–CsBr ETL induced a negative shift in flat band potential (Vfb) from −0.46 to −0.50 V, which improved the open circuit voltage (VOC), its work function (ɸ) from −4.71 to −3.75 eV and increased conduction band minimum (CBM) from −3.58 to −2.42 eV. CsBr incorporation increased electron density in TiO2 matrix, indicating the suppression of trap state and significantly improved the overall photovoltaic performance of DSSCs.

NiSe2-CoSe2 hollow polyhedron as counter electrode catalyst for high-efficiency dye-sensitized solar cells

The design of efficient counter electrode (CE) materials for dye sensitized solar cells (DSSCs) strongly depend on the microstructure construction and the effective combination of different active components. In this study, a hollow polyhedral structured NiSe2-CoSe2 composite electrode was synthesized through the direct selenization of the hollow nanocage morphology nickel-cobalt layered double hydroxide (NiCo-LDH) ultrathin nanosheets, which was derived from ZIF-67 nanocrystals. Notably, owing to the unique hollow structure and synergistic effect of the Ni-Co bimetallic selenides, the hollow polyhedral NiSe2-CoSe2 CE exhibited the expected electrochemical catalytic activity in the reduction of triiodide, as revealed by electrochemical impedance spectroscopy, cyclic voltammetry and Tafel polarization measurements. The photovoltaic results revealed that the PCE of the NiSe2-CoSe2 CE reached 8.21 %, which was higher than those of the Pt and CoSe2 CEs (7.62 % and 6.78 %, respectively). Moreover, the hollow NiSe2-CoSe2 CE exhibited a favourable photocurrent response upon light on-and-off cycling and improved stability over multiple start. This study provides a meaningful reference for the construction of hollow polymetallic transition-metal selenides for DSSC devices.

High efficiency dye-sensitized solar cells with a novel two dimensional Cd-V-LDH photoanode

The present study demonstrates a novel photoanode layer double hydroxide (LDH) for dye-sensitized solar cells (DSSCs). The search for a photoanode (PA) with low cost and high power conversion efficiency (PCE) has become one of the most significant challenges facing researchers. LDH has proven successful as a photocatalyst in various fields. In this paper, a novel Cd-V-LDH with a molar ratio of Cd:V = 1:1 was synthesized by the coprecipitation method and used as a novel PA in DSSCS. X-ray diffraction (XRD), Raman spectroscopy, Scanning electron microscopy (SEM), Fourier Transform infrared spectroscopy (FTIR), Nitrogen sorption analysis, UV–Vis absorption spectrum, Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were used to examine the produced Cd-V-LDH. Cd-V-LDH as PA, Eosin Y (EY) as a photosensitizer, LiI-I2 as a liquid electrolyte, and g-C3N4 (GN) as a photocathode (PC) are the component of DSSCs. The series cells of DSSCs were assembled and the available variables have been studied to achieve the best performance under normal conditions. These variables, e.g., concentration and pH of EY, active area of PA, and different types of PC, e.g., graphene oxide (GO), commercial carbon (CC), and (GN). The open circuit voltage (VOC) and short circuit current density (JSC) for the Cd-V-LDH/EY/LiI-I2/GN system were observed to be 705 mV and 12.40 mA/cm2, and has a PCE of 5.4% comparable to Cd-V-LDH/EY/LiI-I2/GO and Cd-V-LDH/EY/LiI-I2/CC, which have PCEs of 4.9% and 3.8%, respectively, in the identical testing conditions.

Theoretical investigation on the influence of electron-accepting substitutions in modulating the optoelectronic properties of dye-sensitized solar cells

we explore the efficiency of D-π-A organic dyes in dye-sensitized solar cells (DSSCs). Five dyes with varied acceptor sizes and geometric structures are studied. Quantum mechanics calculations, utilizing density functional theory (DFT) and time-dependent density functional theory (TD-DFT), are used to assess their efficacy. Each dye has a simple push-pull architecture, featuring an arylamine electron donor and a furan conjugated spacer, with different acceptor groups incorporated. By fabricating high-efficiency DSSCs with these designed dyes, we evaluate their performance as light-harvesting sensitisers. Key parameters, such as short-circuit current density, open-circuit voltage, light-harvesting efficiency (LHE), electronic injection-free energy (ΔGinject), and regeneration driving forces (ΔGreg), are studied using quantum mechanics calculations. Our aim is to gain insights into the potential of these dyes to enhance the efficiency of DSSCs. By analyzing their structural and functional properties, we can better understand their effectiveness as sensitisers. This research contributes to the expansion of cost-effective and highly efficient dye-sensitized solar cells.

Ni–CoS2/WS2/MoS2 hollow cuboids as noble metal-free bifunctional catalysts for highly efficient photovoltaics and electrochemical hydrogen production

Transition metal compounds, especially NiS2, CoS2, WS2, and MoS2 as noble metal-free catalyst materials, are widely applied to replace Pt in the fields of dye-sensitized solar cells (DSSCs) and hydrogen evolution reactions (HER). Meanwhile, hollow structures have large specific surface area and their large void spaces can also effectively reduce ion migration resistance and diffusion length. In this work, Ni–CoS2/WS2 and Ni–CoS2/MoS2 hollow cuboids have been successfully synthesized and applied as promising bifunctional electrocatalysts in high-efficiency DSSCs and HERs. In detail, nickel-cobalt hydroxide cuboids were prepared and served as self-sacrificing templates to react with (NH4)2WS4 or (NH4)2MoS4 at room temperature, and then mixed with sulfur powder for annealing treatment. Besides, Ni–CoS2 hollow cuboids were synthesized as a reference. Profiting from the stable hollow structure, large specific surface area, abundant effective active sites exposed by WS2, and synergistic effect of multiple elements, Ni–CoS2/WS2 hollow cuboids manifested a preeminent performance. Compared with Pt (8.06%), the conversion efficiency of Ni–CoS2/WS2 hollow cuboids had reached 9.41% as counter electrode for DSSCs. As for HER, it exhibited the lowest overpotential of 72.4 mV@10 mA cm−2 and had the minimum Tafel slope (56.1 mV dec−1) compared with Ni–CoS2/MoS2 and Ni–CoS2.

High-efficiency dye-sensitized solar cells fabricated with electrospun PVdF-HFP polymer nanofibre-based gel electrolytes

High-efficiency dye-sensitized solar cells fabricated with electrospun PVdF-HFP polymer nanofibre-based gel electrolytes

Self-Seeding Synthesis of Hierarchically Branched Rutile TiO2 for High-Efficiency Dye-Sensitized Solar Cells.

This study presents a unique and straightforward room temperature-based wet-chemical technique for the self-seeding preparation of three-dimensional (3D) hierarchically branched rutile TiO2, abbreviated HTs, employing titanate nanotubes as the precursor. In the course of the synthesis, spindle-like rutile TiO2 and the intermediate anatase phase were first obtained through a dissolution/precipitation/recrystallization process, with the former serving as the substrates and the latter as the nucleation precursor to growing the branches, which finally gave birth to the production of 3D HTs nanostructures. When the specifically created hierarchical TiO2 was used as the photoanode in dye-sensitized solar cells (DSCs), a significantly improved power conversion efficiency (PCE) of 8.32% was achieved, outperforming a typical TiO2 (P25) nanoparticle-based reference cell (η = 5.97%) under the same film thickness. The effective combination of robust light scattering, substantial dye loading, and fast electron transport for the HTs nanostructures is responsible for the remarkable performance.

Photovoltaics literature survey (no. 182)

Photovoltaics literature survey (no. 182)

Dye-sensitized solar cells with efficiency enhancement surpassing 65% through layer-by-layer assembled plasmonic photoanodes

Even though plasmonic photoelectrodes have paved the way for high-efficiency DSSC, metal nanoparticle degradation in iodine-based electrolytes restricts commercialization. In order to protect the plasmonic nanoparticles, the plasmonic photoelectrode having a layer-by-layer assembly of TiO2/Ag/TiO2 has been developed by a simple photoreduction at various time intervals followed by mild TiCl4 treatment over the TiO2 film and fabricated into dye-sensitized solar cells (DSSC). On evaluating the performance of fabricated DSSC under AM 1.5 G irradiation with the intensity of 100 mWcm−2, the champion cell (η = 11%) shows 65% enhancement in power conversion efficiency compared to the pristine TiO2 photoanode-based DSSC (η = 6.67%). The photocurrent density has been improved due to the surface plasmon resonance effect of Ag nanoparticles and the formation of TiO2 by TiCl4 treatment not only protects the Ag metal nanoparticles as well as creates more dye-loading sites. A negative shift in the Fermi-level caused by the accumulation of electrons in Ag, triggers the open-circuit voltage to increase by 100 mV which is evident from the Mott-Schottky analysis. The electron lifetime value is increased due to increased charge collection efficiency. The champion cell shows 91.5% retainment in efficiency even after 5 days.

AuNRs attached TiO2 NPs modified by cobalt-imidazolate frameworks as exceptional materials to improve the energy conversion efficiency of dye-sensitized solar cells.

This work reports a significant improvement in both the open-circuit voltage (VOC) and current density (J) of dye-sensitized solar cells (DSSCs) using gold nanorod-modified TiO2 nanoparticles (TiO2/AuNRs) together with a cobalt-imidazolate framework (ZIF-67) as an efficient photoanode. It was demonstrated that adding ZIF-67 (8 wt%) to TiO2 NPs increased the VOC by 160 mV and J by 2.5 times. This observation was described based on the significant increase in the amount of adsorbed dye in the presence of highly porous ZIF-67, which boosts the photoanode's light harvesting. Modifying TiO2 NPs with AuNRs also caused a remarkable enhancement in J (∼ 2.8 times), which can be explained via electron transfer between the TiO2 conduction band and AuNRs. It can result in a more efficient inhibiting effect on the interfacial charge recombination processes in TiO2/AuNRs/ZIF-67 because of the formation of a Schottky barrier at the interface between TiO2 and Au. These effects were confirmed by the reduction in the photoluminescence intensity of TiO2 in the presence of AuNRs. More reduction in the photoluminescence intensity was observed when ZIF-67 was added. The prepared photoanode showed an outstanding improvement in the overall efficiency of the DSSC (η) to 8.38% compared to the bare TiO2-based photoanode (1.83%). The notable improvement in the TiO2/AuNRs/ZIF-67 performance confirmed its practicality for high-efficiency DSSCs.

Corrigendum to “Polynary metal selenide CoSe2/NiSe2/MoSe2 porous nanospheres as efficient electrocatalytic materials for high-efficiency dye-sensitized solar cells” [J. Electroanal. Chem. 924 (2022) 116888

Corrigendum to “Polynary metal selenide CoSe2/NiSe2/MoSe2 porous nanospheres as efficient electrocatalytic materials for high-efficiency dye-sensitized solar cells” [J. Electroanal. Chem. 924 (2022) 116888

CoP@Ni2P microcrystals in situ grown on carbon fiber as counter electrode catalysts for high-efficiency dye-sensitized solar cells

Transition metal phosphides (TMPs) have recently emerged as outstanding energy conversion and storage materials for their highly active surface sites, electrical conductivity, and thermal and structural stability. However, TMPs as the counter electrode (CE) of dye-sensitized solar cells (DSSC) are rarely reported. Here, cobalt phosphide and nickel phosphide (CoP@Ni2P) microcrystals were successfully prepared in situ grown on carbon fiber of carbon paper (CP) by using simple hydrothermal and phosphating methods, and served as CE in DSSCs. The CP acted as a supporting conductivity substrate and an electron transport “speedway,” which can enhance the electrocatalytic ability of CE and photoelectric conversion efficiency of the devices. The cells based on CoP@Ni2P@CP CE with 1 mmol NiCl2·6H2O deliver a power conversion efficiency of 8.33%, which is superior to that of state-of-the-art Pt-based cell (7.54%). Moreover, the CoP@Ni2P@CP CE also displays a small charge transfer resistance (2.07 Ω cm2) at the interface between electrolyte and CE, as well as prefect electrochemical catalytic stability in I−/I3− electrolyte. These findings indicate that the CoP@Ni2P@CP CE possesses outstanding electrocatalytic and photoelectric conversion performance along with desired stability to be utilized as an efficient Pt-free alternative in DSSCs.

Polynary metal selenide CoSe2/NiSe2/MoSe2 porous nanospheres as efficient electrocatalytic materials for high-efficiency dye-sensitized solar cells

• CoSe 2 /NiSe 2 /MoSe 2 porous nanosphere was synthesized. • CoSe 2 /NiSe 2 /MoSe 2 had abundant active sites and excellently catalytic activities. • The PCE of CoSe 2 /NiSe 2 /MoSe 2 (9.49%) was higher than that of Pt (8.28%). Transition metal selenides with porous structure have a brightly prospects due to their low cost, large surface area, high catalytic efficiency, and facile synthetic method comparing with Pt-based electrocatalytic materials in power transformation systems. Herein, we have successfully prepared porous structure transition metal selenide CoSe 2 /NiSe 2 /MoSe 2 nanospheres through simple solvothermal method and stepwise selenization process from glycerol precursor nanospheres. Uniform selenide nanoparticles were formed on the surface of the porous nanospheres. The resultant CoSe 2 /NiSe 2 /MoSe 2 porous nanospheres not only provided more redox pairs, but also had better electron transfer performance and shorter charge transfer distance between the electrolyte and the electrode materials, accelerating the charge transfer process. Therefore, CoSe 2 /NiSe 2 /MoSe 2 nanospheres delivered excellent electrochemical performance in dye-sensitized solar cells which achieved an excellent power conversion efficiency of 9.49% comparing to the cell based on Pt (8.28%). This work can offer a new vision on the design of high-performance, environment-friendly, and Pt-free electrocatalysts for solar cells.

Carbazole based D-πi-π-A dyes for DSSC applications: DFT/TDDFT study of the influence of πi-spacers on the photovoltaic performance

In this study, we have designed a series of novel D-πi-π-A organic dyes with different πi-spacers (Di, i = 2–8) for dye-sensitized solar cells (DSSC) based on the synthesized dye D1 to improve the photovoltaic performance of these designed organic dyes. The influence of different types of πi-spacers on the sensitizer properties was studied theoretically by density functional theory (DFT) and time-dependent density functional theory (TDDFT) methods aimed at revealing structure–property structures. The calculated results show that replacing the thionothiophene (π1) as a donor electron-rich group with electron-deficiency groups (π2-π8) results in a significantly smaller HOMO-LUMO energy gap and a broader absorption spectrum for all designed dyes. This results reveal that these designed dyes would be used as promising sensitizers for DSSCs, and D6 could be the excellent candidate for high efficiency DSSCs due the planar geometry, a small energy gap (1.78 eV), longer wavelength absorption (756.95 nm), longer lifetimes (9.23 ns), a lower ΔGreg (0.17 eV), a large dipole moment of D6-(TiO2)6 (21.94 D), and reasonable energy reorganization (0.536 eV). This theoretical investigation is expected to provide new strategies to synthesize efficient sensitizer for DSSCs.

A strategy for efficient parallel tandem dye-sensitized solar cells based on doubled-sided Pt electrode with a novel phenothiazine-based dye and N719

The tandem idea of the dye-sensitized solar cells (DSSCs) is considered as a promising route to break through the barrier for the development of the DSSCs through extending the absorption spectra and improving the short-circuit photocurrent density (Jsc) or open-circuit voltage (Voc). In this paper, an innovative 2-phenothiazine-phenylamine-based organic dye PTZ-17 with complementary optical properties to dye N719 was exploited. The parallel tandem dye-sensitized solar cells (PT-DSSCs) with a doubled-sided Pt electrode which are composed of a N719-based top cell and a PTZ-17-based bottom cell were manufactured and exhibited a high photoelectric conversion efficiency of 10.52%. From our work, a new strategy is provided for the further exploration of the dye molecular selection and the high-efficient DSSCs preparation.

Facile Synthesis of TiO2 Nanoparticles and Their Reduced Graphene Oxides (RGO) Based Nanocomposites as Electrodes for Dye Sensitized Solar Cells (DSSCs) with Enhanced Efficiency

Recently, Dye-sensitized solar cells (DSSCs) have very attracted a huge deal of industries and academics owing to its number of properties including cost-effectiveness, and practically high power energy conversion efficiency. However, there is always a need to develop new research technologies to increase solar cells efficiency based on oxide heterojunctions. In this work, a fast, environment friendly and economic route were used to prepare TiO2, and their nanocomposites containing reduced graphene oxide (RGO), and carbon nanotubes (CNTs) for the fabrication of DSSCs device onto ITO substrates. The prepared nanostructures were well characterized by X-Ray diffraction (XRD), FESEM, TEM, and Raman measurements. XRD analysis confirmed that TiO2 nanoparticles were crystalline with tetragonal phase. Morphological studies performed by FESEM and TEM images showed that the TiO2 possessed spherical morphology which were uniform and densely covered on the surface of the RGO nanosheets. The DSSCs were fabricated using prepared TiO2 nanoparticles and nanocomposites with RGO and CNTs as working electrode. The results revealed that the DSSCs fabricated using nanocomposites showed enhanced performance as compared with the pure samples without RGO. In particular, the TiO2/CNTs (0.5 wt%) nanocomposites electrode exhibited highest power conversion efficiency (PCE) of DSSCs with a maximum value of 0.679% compared to 0.269% of DSSC with pure TiO2, and 0.472% of DSSC with TiO2/RGO. This method would provide a pathway to produce a low-cost technological process to develop high efficiency DSSCs.

Synthesis of innovative triphenylamine-functionalized organic photosensitizers outperformed the benchmark dye N719 for high-efficiency dye-sensitized solar cells

Herein, we present a thorough photovoltaic investigation of four triphenylamine organic sensitizers with D–π–A configurations and compare their photovoltaic performances to the conventional ruthenium-based sensitizer N719. SFA-5–8 are synthesized and utilized as sensitizers for dye-sensitized solar cell (DSSC) applications. The effects of the donor unit (triphenylamine), π-conjugation bridge (thiophene ring), and various acceptors (phenylacetonitrile and 2-cyanoacetamide derivatives) were investigated. Moreover, this was asserted by profound calculations of HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) energy levels, the molecular electrostatic potential (MEP), and natural bond orbital (NBO) that had been studied for the TPA-sensitizers. Theoretical density functional theory (DFT) was performed to study the distribution of electron density between donor and acceptor moieties. The sensitization by the absorption of sensitizers SFA-5–8 leads to an obvious enhancement in the visible light absorption (300–750 nm) as well as a higher photovoltaic efficiency in the range of (5.53–7.56%). Under optimized conditions, SFA-7 showed outstanding sensitization of nanocrystalline TiO2, resulting in enhancing the visible light absorption and upgrading the power conversion efficiency (PCE) to approximately 7.56% over that reported for the N719 (7.29%). Remarkably, SFA-7 outperformed N719 by 4% in the total conversion efficiency. Significantly, the superior performance of SFA-7 could be mainly ascribed to the higher short-circuit photocurrents (Jsc) in parallel with larger open-circuit voltages (Voc) and more importantly, the presence of different anchoring moieties that could enhance the ability to fill the gaps on the surface of the TiO2 semiconductor. That could be largely reflected in the overall enhancement in the device efficiency. Moreover, the theoretical electronic and photovoltaic properties of all studied sensitizers have been compared with experimental results. All the 2-cyanoacrylamide derivative sensitizers demonstrated robust photovoltaic performance.

High-Efficiency Dye-Sensitized Solar Cells: A Comprehensive Review

Keeping in mind our community's dependency on non-renewable sources of energy, it is a gravitating issue that seeks our attention and requires us to switch to renewable sources of energy at the earliest. A Dye-Sensitized Solar Cell (DSSC) is a third-generation photovoltaic technology that has immense capability to become highly commercial in a few years. Along the same lines, it is necessary to highlight that current DSSCs have shallow lifetime values, stability and performance. The efficiency of current DSSCs and the need to tackle their choice of materials and long-term stability is a concern. Some of the highest recorded efficiency values are around 12%, and this calls for severe replacement of conventional DSSC materials, modifications in the device structure and molecules, and improvement in testing and scaling-up measures. This review article underlines an introduction to DSSCs, working principle, components, high-efficiency DSSCs, strategies to improve device performance, DSSCs research in India, the advantages and disadvantages of the device, and recent research on fruit and flower-based DSSCs. Keywords: Dye-Sensitized Solar Cells, Solar Cell Materials, Third Generation Photovoltaics, High-Efficiency Dye-Sensitized Solar Cells, Solar Cells.

Synthesis and Photoluminescence Properties of Alkylbromoporphyrin

<p>The usage of porphyrin as a light-harvesting chromophore is considered as one of the keys to obtaining low-cost and high-efficiency dye-sensitized solar cell (DSSC). In this paper, a novel porphyrin, 5,10,15-tris(nitrophenyl)-20-(p-(11-bromo)dodecoxyphenyl))porphyrin, having a long alkyl chain and three nitro groups was synthesized. The nitro groups serve as anchoring groups to TiO<sub>2</sub> surfaces and long alkyl chain prevents unwanted dye aggregation. The porphyrin was synthesized by condensation of <em>p</em>-(12-Bromododecoxy)benzaldehyde and pyrrole in propionic acid according to an adaptation of the general Rothemund method <a href="https://doi.org/10.1021/ja01265a096">[1]</a>. <em>p</em>-(12-Bromododecoxy)benzaldehyde was synthesized by nucleophilic substitution reaction between 4-hydroxybenzaldehyde and 1,12-dibromododecane in acetone. The reaction products were analyzed by <sup>1</sup>H-NMR and mass spectroscopy. The absorption and fluorescence spectra of the porphyrin were also recorded. As results, the absorption spectrum of the porphyrin consists of a strong Soret and four weak Q-band. Compared to 5,10,15-tris(nitrophenyl)-20-(p-(11-bromo)dodecoxyphenyl))porphyrin spectrum, there is no wavelength shifting because of the incorporation of the alkyl chain. The fluorescence spectrum of the porphyrin shows two characteristic emission bands and the intensity ratio of those emission bands is always constant when irradiated by different excitation wavelength related to Soret and Q-band.</p>

Toward Eco-Friendly Dye-Sensitized Solar Cells (DSSCs): Natural Dyes and Aqueous Electrolytes

Due to their low cost, facile fabrication, and high-power conversion efficiency (PCE), dye-sensitized solar cells (DSSCs) have attracted much attention. Ruthenium (Ru) complex dyes and organic solvent-based electrolytes are typically used in high-efficiency DSSCs. However, Ru dyes are expensive and require a complex synthesis process. Organic solvents are toxic, environmentally hazardous, and explosive, and can cause leakage problems due to their low surface tension. This review summarizes and discusses previous works to replace them with natural dyes and water-based electrolytes to fabricate low-cost, safe, biocompatible, and environmentally friendly DSSCs. Although the performance of “eco-friendly DSSCs” remains less than 1%, continuous efforts to improve the PCE can accelerate the development of more practical devices, such as designing novel redox couples and photosensitizers, interfacial engineering of photoanodes and electrolytes, and biomimetic approaches inspired by natural systems.