N719 Dye Research Articles

Hoisting photovoltaic performance of perovskite BaSnO3 nanoparticles wrapped reduced graphene oxide: Efficient photoelectrode for dye-sensitized solar cell

Inorganic perovskite nanostructure photoanode has a very important role in dye-sensitized solar cells (DSSC),in collecting photogenerated electrons coming from dye sensitizer. The photo-electric-conversion efficiency of photoelectrode is hindered by an effective photogenerated electron hole/pair. To avoid this problem, modification of BaSnO3 perovskite nanoparticles with graphene nanosheets is attempted in our work. Facile one-step synthesis of RGO loaded BaSnO3 (RGO-BaSnO3 NC) was done by simple solution route. As-prepared perovskite composite was studied using characterization techniques namely Raman spectroscopy, high-resolution transmission electron microscopy (HR-TEM) and field emission scanning electron microscopy (FE-SEM). The photovoltaic performances of RGO-BaSnO3 NC-based photoanode in DSSC employing N719 dye, Pt-counter electrode and imidazole-based liquid electrolyte have been studied under standard simulated lighting of 100 mW cm−2. It was found that RGO-BaSnO3 NC showed better dye adsorption to facilitate light harvesting and promoted a proficient electron transport pathway owing to fewer electron trapping sites on the surface than the pristine BaSnO3 NPs surface. The results demonstrate that the fabricated DSSC made with RGO-BNC-based photoanode delivered overall photoelectric conversion efficiency of 5.59 %, which is 32 % higher than that of DSSC fabricated unmodified BaSnO3 photoanode.

Co-sensitization effect of N719 dye with Cu doped CdS colloidal nanoparticles for dye sensitized solar cells

Co-sensitization effect of N719 dye with Cu doped CdS colloidal nanoparticles for dye sensitized solar cells

Effect of D-limonene additive in copper redox-based quasi-solid-state electrolytes on the performance of dye-sensitized solar cells

In dye-sensitized solar cells (DSSCs), the copper redox mediator has been proven to enhance power conversion efficiency (PCE) due to the fairly low driving force for dye regeneration. In this work, we prepared six blended biopolymer-based electrolytes (E1 to E6) to regenerate N3 Dye absorbed in TiO2 for dye-sensitized solar cell application. The regeneration behavior of three different electron-withdrawing substituents on 2-(pyridin-2-yl)− 1 H-benzo[d]imidazole ligands coordinated with copper metal, its forms [Cu(mpimb)2]1+/2+ (methyl 4-((2-(pyridin-2-yl)− 1 H-benzo[d]imidazol-1-yl)methyl) benzoate), [Cu(pbimb)2]1+/2+ (4-((2-(pyridin-2-yl)− 1 H- benzo[d]imidazol-1-yl)methyl) benzonitrile) and [Cu(ptpbi)2]1+/2+ (2-(pyridin-2-yl)− 1(4-(trifluoromethyl)benzyl)− 1 H-benzo[d]imidazole). Commencing their electrochemical and photophysical properties determines the molecular orbital energy level of the complex. A quasi-solid-state electrolyte (QSSE) medium is blended in a biopolymer host (pectin and 2-hydroxyethylcellulose). Additionally, a comparison study has been performed between commercially available pyridine-based-additive [tert-butyl pyridine (TBP)], and a bio-organic compound extracted from orange peel waste (1-methyl-4-(prop-1-en-2-yl) cyclohex-1-ene (limonene)) used as an additive material. Using these newly designed copper redox mediators and additives, the six sets of DSSCs devices has constructed. The cell structure is assembled as TiO2/N3 dye/electrolyte (E1 to E6)/Pt. Among the fabricated devices, C1 and C2 redox couples [Cu(ptpbi)2]1+/2+ having CF3 substituent exhibit maximum Voc and Jsc. Interestingly, the device with limonene additive exhibited PCE up to 4.4 %, whereas with TBP, it showed 4.0 % efficiency. The PCE results of the C2 device sustained some electrochemical factors such as Bulk Resistance (Rb =142.0 Ω), Recombination Resistance (Rrec = 191.4 Ω), Charge Transfer Resistance (Rct = 98.84 Ω), Chemical capacitance (Cμ = 7.882 μF), Ionic Conductivity (σ = 2.816 ×10−04 S cm−1), electron lifetime (τn = 16.24 μs), Diffusion length (Ln =1.39 × 10−01 mm).

Synthesis of pyrene-centered D-π-a structured dyes for efficient dye-sensitized solar cells

An asymmetric pyrene derivative was designed as a dye with D-π-A structure. This dye was synthesized by the following steps (acylation reaction, Friedele Crafts acylation reaction, bromination reaction, Hagiharae Sonogashira cross-coupling reaction, and knoevenagel condensation reactions). The structure of the dye was analyzed and identified by FT-IR and 1H-NMR. The dye-sensitized solar cells were prepared with the dye and TiO2 electrode. Futhermore, the I-V curves and IPCE curves of the dye-sensitized solar cells were investigated detailedly. The result showed that the photoelectric conversion efficiency of the dye-sensitized solar cells reached 33.5% of N719 dye cells.

A Comparative Study of Organic Dye-Sensitized Solar Cells Based on Anatase TiO2 and Amorphous Free Mixed Phase’s Anatase/Rutile P25 TiO2 Photoanodes

Dye-sensitized solar cells (DSCs) remain an interesting photovoltaic concept, although recent times have seen their envisioned broad-scale applications being replaced with more niche ones. Nevertheless, as a key component of DSCs, titanium(IV) oxide (TiO2) must be produced in a large volume, low cost, and highly reproducible manner. Degussa P25 remains a benchmark TiO2 product, addressing the first two of the above points very well. Post-treatment processes that may also be carried out on a large scale give some hope to addressing the reproducibility issue. This paper builds on our previous works wherein mixed-phase P25 (anatase + rutile + amorphous TiO2) was converted into an amorphous free form by selectively dissolving and recrystallizing the amorphous component. Here we investigated the performance of metal-free organic dye (D149)-based DSCs with three different TiO2 films: (1) as-received P25 (TiO2-P25), (2) amorphous-free P25 (TiO2-HP25), and (3) anatase nanoparticles obtained from Dyesol (TiO2-DSL). DSCs based on TiO2-HP25 showed comparable performance (5.8 ± 0.2% PCE) to DSCs based on the TiO2-DSL (5.8 ± 0.4% PCE) and substantially higher than for devices based on the as-obtained P25 nanoparticles (3.9 ± 0.4% PCE). The enhancement resulting from the post-processing of P25 derives from simultaneous increases in photo-current density (Jsc), open-circuit voltage (VOC), and the fill factor (FF), due to enhancing the dye-loading capability and the charge-transport efficiency (suppressing the electron recombination) as a result of the removal of amorphous barriers and associated defect states. This is in line with enhancing DSC performance based on the organometallic N719 dye we reported previously. However, the photoanode material based on abundant P25 TiO2 sensitized with high-extinction-coefficient organic D149 dye can be adopted as a cost-effective DSC as an alternative to relatively high-cost DSCs based on the commercial anatase TiO2 sensitized with organometallic N719 dye.

Synthesis of TiO2/ZnO photoanodes on FTO conductive glass for photovoltaic applications

For oxide semiconductors for application in dye-sensitized solar cells (DSSCs), titanium dioxide conjugated with zinc oxide thin films was synthesized and characterized. The UV (ultraviolet) spectrum characterization showed a peak of absorbance at around 355 nm, with a band gap of 3.25 eV and reflectance around 85%. Such characteristics allowed the fabrication of DSSCs with N719 dye, under simulated light of 100 mW/cm2. The highest efficiency of 1.17% was at 5% titanium dioxide and 4 h of dye immersion.

Graphene Quantum Dots as a Co-Sensitizer With Improving Light Absorption for Dye-Sensitized Solar Cells

We improve photovoltaic performance by incorporating graphene quantum dots (GQDs) into dye-sensitized solar cells (DSSCs). GQD can emit green fluorescence (∼530 nm) in the ultraviolet wavelength range (∼340 nm), and this characteristic is applied to enhance the light absorption ability of N719 dye. Using GQDs as auxiliary sensitizers to achieve co-sensitization with N719 dye can enhance the photovoltaic performance of DSSCs. We observed the photoresponse characteristics of DSSCs with different sensitization effects by incident photon-to-current conversion efficiency (IPCE). According to the results, the photoelectric conversion efficiency of DSSCs using the GQD+N719 co-sensitized photoanode was increased to 5.14%, which is a 20% improvement.

Investigation on optical properties and photovoltaic performance of solid-state dye-sensitized solar cells comprised of photoanodes of titanium dioxide nanoparticles calcinated at different temperatures

Dye-sensitized solar cells (DSSCs) were constructed using photoanodes of TiO2 nanoparticles (Degussa P25) calcinated at diverse temperatures. The calcinated TiO2 nanoparticles were characterized by X-ray diffraction (XRD) technique and N719 dye anchored TiO2 thin films were subjected to diffuse reflectance spectral and dye desorption studies. The band gaps of TiO2 nanoparticles calcinated at higher temperatures (700 and 900 °C) were shifted to lower energy levels by predominant anatase phase transformation into rutile and increase in the particles size. The performance of DSSCs with TiO2 (Degussa P25) nanofiller incorporated solid-state PEO electrolyte was examined at light intensity of 60 mW cm−2. The DSSC with TiO2 (Degussa P25) nanoparticles photoanode was exhibited overall efficiency of 1.86%, which was ∼4.9 and 9.8-folds greater over the DSSCs having photoanodes of TiO2 nanoparticles calcinated at 700 and 900 °C, respectively. This can be attributed to higher surface area of TiO2 nanoparticles that facilitates higher dye adsorption and predominant anatase phase for favorable electron transfer. The DSSCs stability was confirmed through chronoamperometry experiments.

Molecular-engineering of Tb2O3@TiO2 complexes sensitized with N719 dye photoanodes and evaluation of their realistic efficiencies in DSSC systems

Molecular-engineering of Tb2O3@TiO2 complexes sensitized with N719 dye photoanodes and evaluation of their realistic efficiencies in DSSC systems

Investigation of the structural and electrochemical properties of a ZnO–SnO2 composite and its electrical properties for application in dye-sensitized solar cells

This study compares photovoltaic and electrochemical properties of nano sized ZnO–SnO2 composite as photoanode material made by a simple but effective mechanical mixing method with Ru N719 dye for energy harvesting applications in DSSCs.

Synthesis of Conjugated bis-Schiff Base and Their Complexes as Dye-Sensitizer for Dye Sensitized Solar Cell (DSSC) Application

Schiff base and their metal complexes have been widely used as photovoltaic materials due to their excellent π-electron transfer properties along the molecule. A total of eleven conjugated symmetrical bis-Schiff base and their complexes with different π-spacers have been synthesized and spectroscopically characterized in order to investigate their conversion efficiency in dye-sensitizer solar cells (DSSC). All compounds were either substituted with hydroxy (-OH) or methoxy (-OMe) as the electron donor and difluoro boron (BF2) as the electron acceptor or without any substituent. All compounds were applied as dye-sensitizer in DSSC using titanium (IV) oxide (TiO2) coated on a fluoride doped tin oxide glass as the working electrode and electric paint containing carbon black, whereas graphene coated indium tin oxide glass as the counter electrode. The power conversion efficiencies of the eleven bis-Schiff bases were compared to N3 Dye as the benchmark standard. The results showed that the compound with aromatic ring bridge as the π-spacer and -OMe substituent gave the highest efficiency at 0.0691% whereas the compound with aromatic ring and BF2 gave the lowest efficiency at 0.0012%.

Tuning TiO2 Porosity of Multilayered Photoanode Towards Enhanced Performance of Dye Sensitized Solar Cell

In this paper, we prepared Titanium Dioxide (TiO2) based dye sensitized solar cells (DSSC). Downscaling of commercial TiO2 powder have been achieved by systematic ball milling carried out using home-made ball milling device. Thin films were prepared and samples were characterized by XRD, SEM, UV-Vis and I-V. The main objective of this work is to prepare TiO2 based (DSSC) using N3 dye and study the effect of the TiO2 grain size inside the photoanode layer on the efficiency of the solar cell. UV-vis study of nanometer sized TiO2 particles showed that the energy gab has shifted towards the lower wavelength in electromagnetic spectrum (blue shift), and then optical band gap is an indirect and allowed transition. Energy gap calculations of related grain size of showed quantum confinement effect. A sophisticated strategy for TiO2 films consisting of tailoring monolayer, bilayer and trilayer of mixed multisized nanoparticles were adopted and investigated as DSSC electrodes. Our results showed that the dye sensitized solar cells can be substantially altered due to the designs and the particle size distributions of the TiO2 photoelectrode. The maximum efficiency of 0.5% was reached by TiO2 photoelectrode designed as a trilayer with a particles of wide size distribution from about 12 to 340 nm in the middle layer. The approach of light scattering in submicrometer‐sized TiO2 nanoparticles aggregates was adopted in order to interpret the enhancement of our DSSC efficiency over extending the length transported by electromagnetic wave hence to promote the light acquiring efficiency of photoelectrode thin film. The relatively larger particle sizes afford the TiO2 films with both better packing and an increased capability for scattering of the incident electromagnetic wave, and hence improves our DSSC efficiency.

Enriched visible light absorption by Au-embedded Sm3+ doped TiO2 compact photoanode for enhanced dye-sensitized solar cell performance

The cooperative effect of Samarium (Sm3+)-doped TiO2 and gold nanoparticles (Au NPs) is investigated in this work to explore its potential to boost visible light absorption in dye-sensitized solar cells (DSSC). As Sm3+ exhibits PL emissions at 583 nm, 612.2 nm, 663.6 nm, and 726.3 nm, there is an overlap with the absorption region of the N719 dye and these PL emission wavelengths resulting in a rise in photocurrent density and PCE owing better UV light harvesting. Sm3+ absorption and emissions were boosted by LSPR (Localized surface plasmon resonance) of Au NPs. As a result, the Au NPs embedded Sm-doped TiO2 photoanode-based DSSC capture more visible light. Sm (0.3)-TiO2 based DSSC reports the highest PCE (η:7.2%) among a series of Sm (0.2%, 0.3%, 0.4%, and 0.5% mol) TiO2 concentrations. Further, with the addition of Au NPs into the Sm3+ -doped TiO2, the PCE is enlarged into (η: 8.33%), which is more than 60% higher than TiO2 photoanode-based DSSC (η: 5.58%).

Molecular design and synthesis of acetohydrazonoyl cyanide structures as efficient dye-sensitized solar cells with enhancement of the performance of the standard N-719 dye upon co-sensitization

Four novel acetohydrazonoyl cyanide compounds (5–8) with a triphenylamine moiety as an electron donor for use in dye-sensitized solar cells (DSSCs) have been designed and synthesized. The target molecules and their intermediates were well characterized using various spectral techniques. Their absorption spectra and electrochemical and photovoltaic properties are extensively investigated and compared with N-719 dye. The photovoltaic efficiency of these new dyes under AM1.5 ranges from 1.91% to 5.17% without the use of any additive. Compound 8 achieved the highest photovoltaic conversion efficiency (PCE, η = 5.17%) among the existing dyes due to the high values of the photocurrent (JSC = 13.66 mA cm−2) and photovoltage (VOC = 647 mV). Due to the good results shown by compound 8, the compound was used as a co-sensitizer along with the N-719 dye to improve its properties and raise its efficiency. The results showed that using (0.2 mM of compound 8 + 0.2 mM of N-719) improved the performance of the fabricated cell (PCE, η = 8.63%) with the enhancement in both VOC (682 mV) and JSC (20.39 mA cm−2) compared to the cell fabricated with N-719 alone (PCE, η = 6.23%, VOC = 623 mV, JSC = 16.48 mA cm−2). Furthermore, electronic excitations simulated using time-dependent DFT agreed well with experimentally obtained sensitizer results, indicating that the exchange-correlation function and basis set used to predict the spectra of the co-sensitizers are quite appropriate for the calculations. In conclusion, the results showed the potential of simple organic co-sensitizers in the development of efficient DSSCs.

Controlling the Layer Thickness of Zinc Oxide Photoanode and the Dye-Soaking Time for an Optimal-Efficiency Dye-Sensitized Solar Cell

Dye-sensitized solar cells (DSSCs) were developed by exploiting the photovoltaic effect to convert solar energy into electrical energy. The photoanode layer thickness significantly affects the semiconductor film’s ability to carry electronic charges, adsorb sensitizing dye molecules, and lower the recombination of photo-excited electrons injected into the semiconductor. This study investigated the dependence of the zinc oxide (ZnO) photoanode thin-film thickness and the film soaking time in N719 dye on the photocurrent–voltage characteristics. The ZnO photoanode was applied to glass using the doctor blade method. The thickness was varied by changing the scotch tape layers. The ZnO-based DSSC attained an efficiency of 2.77% with three-layered photoanodes soaked in the dye for three hours, compared to a maximum efficiency of 0.68% that was achieved with three cycles using the dip-coating method in other research. The layer thickness of the ZnO photoanode and its optimal adsorption time for the dye are important parameters that determine the efficiency of the DSSC. Therefore, this work provides important insights to further improve the performance of DSSCs.

TCO-free dye solar cells based on Ti back contact electrode by facile printing method

The back contact dye solar cells (BCDSCs), in which the TCO(Transparent Conductive oxide) is omitted, have a potential for use of intact low-cost general substrates such as glass, metal foil and papers. Herein, we introduce a facile manufacturing method of a Ti back contact electrode (Ti BCE) for the BCDSCs. We found that the polylinkers such as poly(butyl titanate) have a strong binding property to make Ti particles connect one with another. A porous Ti film, which consists of Ti particles of ≤ 10㎛ size connected by a small amount of polylinkers, has an excellent low sheet resistance of 10 Ω sq-1 for an efficient electron collection for DSCs. This Ti BCE can be prepared by using a facile printing method under normal ambient conditions. Conjugating the new back contact electrode technology with the traditional monolithic structure using the carbon counter electrode, we fabricated TCO-less DSCs. These four-layer structurered DSCs consist of a dye-adsorbed nanocrystalline TiO2 film on a glass substrate, a porous Ti back contact layer, a ZrO2 spacer layer and a carbon counter electrode in a layered structure. Under AM 1.5 G and 100 mWcm−2 simulated sunlight illumination, the four-layer structurered DSCs with N719 dyes and I-/I3-redox electrolytes achieved PCEs up to 5.21 %.

Efficient Ti3C2Tx MXene/TiO2 Hybrid Photoanodes for Dye-Sensitized Solar Cells

Dye-sensitized solar cells (DSSCs) remain a promising technology for clean energy conversion due to their low cost, simple manufacturing, and high scalability. However, to keep these devices competitive against other photovoltaics like organic (OSCs) and perovskite solar cells (PSCs), it is necessary to enhance their efficiency. These improvements can be achieved by optimizing the charge transport and non-radiative carrier recombination within the operating device. Here, we show the design, fabrication, and subsequent characterization of Ti3C2Tx MXene/TiO2 nanocomposite hybrid photoanodes, supported by computational modeling. Ti3C2Tx MXene/TiO2 hybrid photoanodes containing 0.050, 0.075, and 0.100 wt % two-dimensional (2D) Ti3C2Tx flakes were prepared and investigated. The power conversion efficiency (PCE) of the device is found to be enhanced by 20% when only 0.075 wt % Ti3C2Tx was added to TiO2 due to the increase of electron transport in the photoanode. The density functional theory (DFT) calculations of the MXene–TiO2 interface indicate that the anatase potential is lowered, thus increasing the energy difference between the conduction bands of the N719 dye and the nanocomposite and favoring the migration of electrons toward the output terminal. Moreover, DFT results suggest a better separation of the photocarriers at the nanocomposite–N719 interface, which is supported by the measurement of longer electron lifetimes in the photoanode. These features demonstrate that the introduction of Ti3C2Tx into the photoanode is relevant to promote the energy-to-current conversion of DSCCs. Future approaches shall focus on the implementation of different 2D MXene structures to further improve the performance of these class of materials for direct applications in photovoltaic devices and photochemistry.

ZnO/g-C3N4 heterostructures: Synthesis, characterization and application as photoanode in dye sensitized solar cells

A simple low-temperature hydrothermal route was adopted to prepare the binary ZnO/g-C3N4 heterostructures, which were thoroughly characterized by various spectroscopic and microscopic probes. The clearly visible interfaces between the ZnO NRs and g-C3N4 in the HRTEM micrograph verify the formation of ZnO/g-C3N4 heterojunction structures, which, combined with N3 dye, deliver increased optical absorption extending from UV to the visible range. The binary ZnO/g-C3N4 heterostructures are used as the photoanode in the DSSC application. Improvement in the DSSC performance arises because of the growth of the g-C3N4 layer on the ZnO nanorods surface, which efficiently delays the reverse recombination of electrons from ZnO to the electrolyte. The g-C3N4 layer also increases the electron concentration in the photoelectrode and, thereby, directly contributes to the improved performance of the DSSC device. The optimal DSSC based on the ZnO/g-C3N4 photoanode delivers its characteristic JSC ∼14.18 mA/cm2, VOC ∼544 mV, FF ∼0.586 and η ∼4.52%, which is about 2.3 times greater than the DSSC efficiency based on pure ZnO nanorod photoelectrode and retains the spirit of generating the green energy following the photovoltaic endeavor.

Enhancement of Power Conversion Efficiency with Zinc Oxide as Photoanode and Cyanococcus, Punica granatum L., and Vitis vinifera as Natural Fruit Dyes for Dye-Sensitized Solar Cells

Ruthenium N719 is a well-known material used as the dye in commercial dye-sensitized solar cell (DSSC) devices. However, it poses risks to human health and the environment over time. On the other hand, titanium dioxide (TiO2) has low electron mobility and high recombination losses when used as a photoanode in this photovoltaic technology device. In addition, using Ruthenium as the dye material harms the environment and human health. As an alternative sensitizer to compensate Ruthenium on two different photoanodes (TiO2 and ZnO), we constructed DSSC devices in this study using three different natural dyes (blueberry, pomegranate, and black grape). In good agreement with the anthocyanin content in the fruits, black grape, with the highest anthocyanin content (450.3 mg/L) compared to other fruit dyes (blueberry—386.6 mg/L and pomegranate—450.3 mg/L), resulted in the highest energy conversion efficiency (3.63%) for the natural dye-based DSSC. Furthermore, this research proved that the electrical performance of natural dye sensitizer in DSSC applications with a ZnO photoanode is better than using hazardous Ru N719 dye with a TiO2 photoanode owing to the advantage of high electron mobility in ZnO.

The surfactants mediated electropolymerized poly(aniline) (PANI)-reduced graphene oxide (rGO) composite counter electrode for dye-sensitized solar cell

In this work, poly(aniline) (PANI)–reduced graphene Oxide (rGO) low-cost nanocomposite used for counter electrode (CE) in dye-sensitized solar cells (DSSCs) for the replacement of the high-cost platinum (Pt) CE. The nanocomposite CEs were prepared with three different types of structural determine agents (cationic, non-ionic and anionic namely CTAB, Triton-X100, SDS) in aqueous medium and characterized by HR-SEM & TEM, XRD pattern analysis, FT-IR and Raman spectral studies. Electrochemical impedance spectroscopy (EIS) studies were used to determine the PANI-rGO-anionic surfactant in lower charge transfer resistance compared with, PANI, rGO and other type surfactants used in the preparation of CEs. DSSC assembled with a N719 dye sensitized TiO2 photo-anode, Poly(ethylene oxide) (PEO), iodide/triiodide redox couple containing electrolyte and PANI-rGO-anionic surfactant CE showed a sunlight-into-electrical energy conversion efficiency of 7.60%, which is higher than that of DSSC fabricated with pure Pt (6.40%), PANI (4.81%), rGO (4.30%) and PANI-rGO-CTAB (6.26%) and PANI-rGO-Triton X 100 (5.72%).