Bifacial Dye-sensitized Solar Cells Research Articles

High performance Bi-facial dye sensitized solar cells developed using MXenes assisted novel photoelectrode design

A new device architecture of bi-facial dye sensitized solar cell (DSSC) is designed, fabricated by use of novel photoelectrode design contains MXenes. The developed bi-facial DSSC witnessed higher power conversion efficiency (PCE) of 12.82 % with short-circuit current density (JSC) of 27.46 mA/cm2. The DSSC revealed 9.74 % of PCE by front side illumination and 4.57 % by back side illuminations. The results motivated to develop mini-module of series connected 12 test cells, which results in 13.34 % of PCE.

A composite electrocatalytic poly(3,4-ethylenedioxythiophene) film incorporated with silver nanowires for bifacial dye-sensitized solar cells

Poly(3,4-ethylenedioxythiophene) (PEDOT) is a superior electrocatalyst for dye-sensitized solar cells (DSSCs). The porous PEDOT film, however, lacks directional conduction paths, resulting in slower electron transfer and lower cell efficiency. In this study, silver nanowires (Ag NWs) are incorporated into a PEDOT film to construct a PEDOT-coated Ag NW composite film, wherein the Ag NWs serve as highways for charge transport. The composite film is constructed by spreading Ag NWs on tin-doped indium oxide (ITO) glass via a three-step process (dip coating, brush painting, and thermal compression), followed by coating a PEDOT film via electropolymerization. The DSSC catalyzed by the PEDOT-coated Ag NW exhibited an efficiency of 9.22 % under one-sun illumination, outperforming platinum (9.09 % efficiency) and PEDOT (8.33 % efficiency) by increasing the short-circuit current density. Chemical state analyses were performed to determine the interactions between the Ag NWs and PEDOT. Impedance measurements and quantum chemical calculations were conducted to rationalize the functionality of the PEDOT-coated Ag NWs. Owing to its high transparency, the resulting DSSC achieves an efficiency of 6.74 % under rear illumination, demonstrating its high feasibility as a bifacial DSSC. The DSSC also exhibited high efficiencies ranging from 14.05 % to 19.69 % under front-side illumination at low intensities of 300–1000 lux.

Highly transparent and efficient Pt/CeOx counter electrodes for bifacial dye-sensitized solar cells

In this research, we introduce a pioneering approach for enhancing the electrocatalytic performance of counter electrodes (CEs) in dye-sensitized solar cells (DSSCs) by synthesizing Pt/CeOx hybrid nanocatalysts through a refined polyol reduction technique. This method facilitates the accurate production of Pt nanoparticles supported on ceria, leveraging their strong metal-oxide interactions. X-ray photoelectron spectroscopy (XPS) was employed to confirm the co-presence of both metallic and oxidized states of Pt, as well as the mixed valence states of ceria within these nanostructures. The electrocatalytic behavior of these nanocatalysts was rigorously evaluated using cyclic voltammetry (CV), Tafel polarization analyses, and electrochemical impedance spectroscopy (EIS). We identified an optimal Pt/Ce ratio of 1:0.1, which significantly enhanced the kinetics of the iodine reduction reaction (IRR), a crucial factor for efficient DSSC operation. Photovoltaic testing under one-sun AM 1.5 G conditions demonstrated that DSSCs with the optimized Pt/CeOx CEs exhibited a 10 % increase in power conversion efficiency (PCE) comparted to control cells. This study highlights the effectiveness of Pt/CeOx hybrid nanocatalysts in improving bifacial DSSC performance, combining the catalytic strengths of platinum with the unique properties of ceria.

Bifacial dye-sensitized solar cells for indoor and outdoor renewable energy-based application

Bifacial solar cells (BFSCs) are designed to enhance electrical power generation per unit area compared to traditional monofacial cells. They accomplish this by capturing sunlight from both the front and rear surfaces.

Platinum nanoparticles decorated multiwalled carbon nanotube composites as highly transparent, bifacial counter electrodes for dye-sensitized solar cells

Dye-sensitized solar cells (DSSCs) are low-cost solar energy conversion devices with variable color and transparency advantages. DSSCs' potential power efficiency output, even in diffuse light conditions with consistent performance, allows them to be used in building-integrated photovoltaics (BIPV) window applications. Significantly, the development of bifacial DSSCs is getting significant scientific consideration. Triiodide/iodide (I3–/I–) redox couple-mediated DSSCs require highly effective and stable electrocatalysts for I3− reduction to overcome their performance constraints. However, the commonly employed platinum (Pt) cathodes have restrictions on high price and unfavorable durability. Here, we report platinum nanoparticles (Pt NPs) incorporated into multiwalled carbon nanotubes (MWCNT) composites with lower Pt content as an efficient bifacial counter electrode (CE) material for DSSC applications. Pt NPs were homogenously decorated over the MWCNT surfaces using a simple polyol method at relatively low temperatures. CEs fabricated using Pt/MWCNT composites exhibited excellent transparency and power conversion efficiencies (PCE) of 6.92% and 6.09% for front and rear illumination. The results are expected to bring significant advances in bifacial DSSCs for real-world window applications.

Fabrication and Characterization of Bifacial Dye‐Sensitized Solar Cells Utilizing Indoline Dye with Iodine‐ and Cobalt‐Based Redox Electrolytes

Bifacial solar cells are gaining popularity due to their compactness, space‐saving property, and higher photoconversion efficiency (PCE) than mono‐facial solar cells. Bifacial dye‐sensitized solar cells (BF‐DSSCs) are fabricated and characterized utilizing D‐205 as a dye sensitizer in combination with I−/I3− and Co2+/Co3+ redox electrolytes. BF‐DSSCs using iodine‐based electrolytes demonstrate a cumulative PCE and bifaciality factor (BFF) of 13.05% and 85%, respectively. The hampered PCE under backside light illumination is attributed to the absorption of photons by the electrolyte itself. Contrary to this, BF‐DSSCs fabricated using cobalt‐complex‐based redox electrolyte exhibits an exceptionally high BFF of nearly 100% with a PCE of 4.77% and 4.75% under the front‐ and rear‐light illumination, respectively. Although the open‐circuit voltage of the BF‐DSSCs fabricated using cobalt electrolyte (with deeper redox potential) is slightly higher than that of BF‐DSSCs fabricated using iodine electrolyte, their cumulative PCE (9.52%) is much lower than that of iodine‐based device counterparts (13.05%). This decrease in PCE is attributed to the relatively fast charge recombination in the cobalt‐electrolyte‐based BF‐DSSCs.

Phosphorus-doped molybdenum disulfide as counter electrode catalyst for efficient bifacial dye-sensitized solar cells

MoS2 is a promising counter electrode material for dye-sensitized solar cell owing to its optical and electrical properties and two-dimensional layered structure. However, it still suffers from minimal conductivity, poor charge transport and less active sites. The present study offers a promising method for enhancing catalytic and fast charge transfer in MoS2 through heteroatom doping of phosphorus. A facile one-step hydrothermal treatment was acquired to do the phosphorus doping. The spin-coated P-doped MoS2 (MSP2) counter electrode (CE) shows a superior power conversion efficiency of 7.93% for front illumination and 5.34% for rear illumination, outperforming Pt-based (7.41% and 5.75%) CE. Thus, phosphorous incorporation increases the number of active sites and improves the catalytic property of the material. The P-doped MoS2 (MSP2) CE film also shows high transmittance, making it a suitable choice for bifacial type of solar cell.

Bifacial Dye-Sensitized Solar Cells Utilizing Visible and NIR Dyes: Implications of Dye Adsorption Behaviour

Bifacial dye-sensitized solar cells (DSSCs) were fabricated utilizing dye cocktails of two dyes, Z-907 and SQ-140, which have complementary light absorption and photon harvesting in the visible and near-infrared wavelength regions, for panchromatic photon harvesting. The investigation of the rate of dye adsorption and the binding strengths of the dyes on mesoporous TiO2 corroborated the finding that the Z-907 dye showed a rate of dye adsorption that was about >15 times slower and a binding that was about 3 times stronger on mesoporous TiO2 as compared to SQ-140. Utilizing the dye cocktails Z-907 and SQ-140 from ethanol, the formation of the dye bilayer, which was significantly influenced by the ratio of dyes and adsorption time, was demonstrated. It was demonstrated that the dyes of Z-907 and SQ-140 prepared in 1:9 or 9:1 molar ratios favoured the dye bilayer formation by subtly controlling the adsorption time. In contrast, the 1:1 ratio counterpart was prone to form mixed dye adsorption; the best performance of the BF-DSSCs was shown when a dye cocktail of Z-907 and SQ-140 in a molar 9:1 ratio was used to prepare a photoanode for 1 h of dye adsorption. The BF-DSSCs thus exhibited PCEs of 4.23% and 3.48% upon the front and rear side light illuminations, a cumulated PCE of 7.71%, and a very good BBF of 83%.

Combustion-Assisted Polyol Reduction Method to Prepare Highly Transparent and Efficient Pt Counter Electrodes for Bifacial Dye-Sensitized Solar Cells.

A combustion-assisted polyol reduction (CPR) method has been developed to deposit electrocatalytically efficient and transparent Pt counter electrodes (CEs) for bifacial dye-sensitized solar cells (DSSCs). Compared with conventional thermal decomposition of Pt precursors, CPR allows for a decrease in reduction temperature to 150 °C. The low-temperature processing is attributed to adding an organic fuel, acetylacetone (Hacac), which provides extra heat to lower reduction energy. In addition, the stable Pt complexes can simultaneously be formed in ethylene glycol (EG) and Hacac system, which leads to Pt nanoparticle size regulation. A ratio of Hacac to EG is optimized to achieve excellent electrocatalytic activity and high visible light transmittance for CEs. The bifacial DSSCs fabricated with CPR-Pt CEs (EG : Hacac=1 : 16) reach efficiencies of 6.71±0.16% and 6.41±0.15% in front and back irradiations, respectively.

Fuel-assisted polyol reduction for highly transparent and efficient Pt counter electrodes in bifacial dye-sensitized solar cells

Organic fuels allowed for manufacturing highly transparent and efficient Pt counter electrodes.

Transparent PEDOT counter electrodes for bifacial dye-sensitized solar cells using a cobalt complex mediator.

Poly(3,4-ethylenedioxythiophene) (PEDOT) aggregate-deposited counter electrodes (CEs) were applied to bifacial dye-sensitized solar cells with a cobalt complex electrolyte. The high transparency and excellent electrochemical activity of PEDOT CEs result in an impressive cell bifaciality of 0.92 under standard test conditions (AM 1.5G, 100 mW cm-2), and maximum power production of 11.3% under realistic conditions with an effective albedo of 50%.

M1-xSb1-ySδ (M = Ni, Cu, Co) ternary metal sulfides: Emerging candidates for [formula omitted] reduction in bifacial dye-sensitized solar cells

Antimony-based ternary metal sulfides such as Ni9Sb2S8, Cu3SbS3, and CoSbS have been used as counter electrodes (CEs) in bifacial Dye-Sensitized Solar Cells (DSSCs). The electrochemical results show that antimony-based ternary sulfides have the highest peak current density (JPC), lower peak-to-peak separation (EPP) and charge transfer resistance (RCT) than the corresponding binary sulfides. Notably, under front-side illumination, the highest short circuit current (JSC) of 10.19 mA cm−2 is reached for Cu3SbS3, 9.77 mA cm−2 for Ni9Sb2S8 and 10.44 mA cm−2 for CoSbS, all of them are greater than Pt CE. The efficiency of the CoSbS CE is ∼ 97%, Ni9Sb2S8 CE is ∼ 84% and Cu3SbS3 CE is ∼ 66% when normalized with the efficiency of the Pt CE (∼5.54%). The performance of these ternary sulfide CEs is also evaluated for rear-side illumination. This report elucidates the new class of materials that might be used as a potential counter electrode for bifacial DSSCs.

Optical properties of iodine-based electrolyte used in bifacial dye-sensitized solar cells

As third-generation solar cells, dye-sensitized solar cells (DSSCs) can show bifacial harvesting capabilities by utilizing transparent conducting oxides as a counter electrode. Herein, the electrolyte is considered a critical layer from the optical perspective. In this paper, an attempt to estimate the optical properties of Iodine-based electrolytes, typically used in dye-sensitized solar cells, is demonstrated. The refractive index for electrolyte as an effective medium is calculated to be 1.4535 ± 0.005 for an effective thin film of 33.4 ± 0.5 μm thickness, using the near-infrared Fabry–Perot resonances. The extinction (absorption and scattering) and dispersion spectra for the prepared electrolyte were fitted using Lorentz–Dude (LD) model. Finally, the utility of the extracted optical parameters was examined through a finite difference time domain solver, Massachusetts Institute for Technology Electromagnetic Equation Propagation. The simulated optical transmission spectrum perfectly agreed with the measured spectrum with less than 0.1% root–mean–square error. The demonstrated attempt to accurately estimate the refractive index of electrolyte used in DSSCs fabrication may impacted theoreticians who are interested with the optoelectronic modelling of such electrochemical cells, as well as those dealing with optoelectronic devices informatics.

Solution-plasma-induced oxygen vacancy enhances MoOx/Pt electrocatalytic counter electrode for bifacial dye-sensitized solar cells

Bifacial dye-sensitized solar cells (DSCs), harvesting light from both front and rear sides, are potential high-efficiency photovoltaic devices with broad application environments. The electrocatalytic counter electrodes (CEs) of bifacial DSCs could determine the light-harvesting from the rear side and the charge collection of solar cells through electrocatalytic processes. As a result, high-activity and high-transparency CEs are essential for bifacial DSCs. Recently, novel CEs based on strong metal-support interaction (SMSI) have been proven to improve the catalysis and stability of the metal catalytic sites and induce great efficiency increase of bifacial DSCs. However, the contradiction between the transparency and conductivity of support is still a major challenge for the application of SMSI-based CEs on bifacial DSCs. Herein, we utilized a solution plasma (SP) method to introduce oxygen vacancies into a transparent MoOx support film. These SP-induced oxygen vacancies improved the conductivity of MoOx and the interaction between the metal Pt catalytic sites and support, thereby enhancing the catalytic activity and transparency of MoOx/Pt CEs. Consequently, the bifacial DSCs with MoOx/Pt CEs yielded a high efficiency of 7.56% and 6.41% with the front- and rear-side illumination, respectively. This impressive front-to-rear efficiency ratio of 85% indicates that the SP method has a positive effect in constructing high-performance CEs and other electrocatalytic materials based on the SMSI.

Optimization of Pt loading on the counter electrode for efficient and bifacial dye-sensitized solar cells with polymer gel electrolyte

Optimization of Pt loading on the counter electrode for efficient and bifacial dye-sensitized solar cells with polymer gel electrolyte

Performance comparison of nitrile-based liquid electrolytes on bifacial dye-sensitized solar cells under low-concentrated light

Performance comparison of nitrile-based liquid electrolytes on bifacial dye-sensitized solar cells under low-concentrated light

Investigating the variation in the optical properties of TiO2 thin-film utilized in bifacial solar cells using machine learning algorithm

Among various solar cell architectures, dye-sensitized solar cells (DSSCs) and perovskite solar cells have demonstrated the capability of being bifacial as both can be fabricated on conducting glass electrodes. In both cells, TiO2 plays a key role in the optoelectronic properties of the cell. Various studies have reported a range of recipes and deposition techniques for TiO2 thin films. Such variety introduces some uncertainties into the optical properties of the prepared films as well as in the process repeatability. Here, we utilized machine learning methods to correlate the film porosity to the film refractive index, making it capable of studying the impact of varying the fabrication and deposition techniques. Image postprocessing for scanning electron microscope measurements was utilized to estimate the film porosity, and the refractive index was calculated from the T–λ spectra. Four sets of samples with complete bifacial DSSCs were fabricated and characterized. They recorded a maximum current of 23.42 mA. They were fabricated using carboxymethyl cellulose-based suspension and deposited via the spin-coating sol-gel method. The fabricated cells showed an overall conversion efficiency of 7.9% under optical injection of the AM1.5G spectrum from the front side and LED indoor lighting from the counter electrode.

Indoor Dye-Sensitized Solar Cells with Efficiencies Surpassing 26% Using Polymeric Counter Electrodes

The development of high-performance counter electrodes (CEs) for bifacial dye-sensitized solar cells (DSSCs) using nonplatinum (Pt) material is important to prepare low-cost and high-power conversion efficiency (PCE) DSSCs. In this work, poly(3,4-ethylenedioxythiophene) (PEDOT) CEs were prepared by the electrochemical deposition of PEDOT onto fluorine-doped tin oxide substrates for indoor light application. To obtain a high catalytic and high transparent CE, the thickness of the PEDOT film was controlled. Using Y123 dye and cobalt redox system, the cell performance under different light intensities (200–1000 lx) was studied. The results show that the optimal thickness of PEDOT was 90 nm, which can produce higher diffusivity, higher ionic conductivity, and lower charge transfer resistance at the CE/electrolyte interface. Accordingly, PCEs of 23.98% (200 lx), 25.83% (600 lx), and 26.93% (1000 lx) were achieved for a traditional DSSC photoelectrode containing main layer (ML) and scattering layer (SL). For bifacial cells using a newly developed sandwich photoelectrode with the ML/SL/ML structure, the front-side and rear-side efficiencies under 200 lx illumination were 24.16 and 22.45%, respectively, and the rear-to-front-side efficiency ratio was 93%. These efficiencies were much higher than those obtained using Pt CE.

Bifacial dye-sensitized solar cells utilizing green-colored NIR sensitive unsymmetrical squaraine dye

Dye-sensitized solar cells (DSSCs) with the capability of photon harvesting from both front and rear sides, consisting of newly developed NIR dye (SQ-140), iodine-based redox electrolyte, and transparent counter electrode with high bifaciality factor (BFF) and good cumulated photoconversion efficiency (PCE), are successfully fabricated and characterized. The use of transparent TiO2-based photoanode leads to improved BFF as compared to its opaque TiO2 counterparts: from 74% to 86% under similar experimental conditions and device parameters. The high molar extinction coefficient of the NIR dye SQ-140, needing a thinner TiO2 layer, was found to be advantageous to maintaining the high BFF even in thicker TiO2 films without serious compromise in the PCE. The lower efficiency of the bifacial DSSC under rear illumination was attributed to the hampered optical penetration as well as absorption of light by the intense colored iodine-based redox electrolyte.

Polypyrrole‑molybdenum sulfide complex as an efficient and transparent catalytic electrode for bifacial dye-sensitized solar cells

A transparent catalytic counter electrode (CE) with excellent properties plays an important role in the performance improvement of bifacial dye-sensitized solar cells (Bi-DSSCs). In this work, pyrrole is combined with molybdenum sulfide (MoS2) by a refluxing technology and subsequently polymerized in situ to construct polypyrrole (PPy)-MoS2 CEs with high transparency. And compared with the original PPy CE, the PPy-MoS2 CE shows higher electrocatalytic activity for triiodide reduction. A superior power conversion efficiency of 9.48% under both-side irradiation is obtained for the Bi-DSSCs assembled with PPy-4 wt‰ MoS2 complex CE, compared to 7.36% bifacial efficiency for PPy-CE based solar cell.