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Article

Effect of Structural and Material Modifications of Dye-Sensitized Solar Cells on Photovoltaic Performance

by
Paweł Gnida
1,* and
Ewa Schab-Balcerzak
1,2
1
Centre of Polymer and Carbon Materials, Polish Academy of Sciences, 34 M. Curie-Skłodowska Str., 41-819 Zabrze, Poland
2
Institute of Chemistry, University of Silesia, 9 Szkolna Str., 40-007 Katowice, Poland
*
Author to whom correspondence should be addressed.
Coatings 2024, 14(7), 837; https://doi.org/10.3390/coatings14070837
Submission received: 11 June 2024 / Revised: 2 July 2024 / Accepted: 3 July 2024 / Published: 4 July 2024
(This article belongs to the Special Issue Energy Storage and Conversion: From Materials, Devices to Applications)
Browse Figures
Versions Notes

Abstract

:
Dye-sensitized solar cells with synthesized phenothiazine derivative 3,7′-bis(2-cyano-1-acrylic acid)-10-ethyl-phenothiazine (PTZ) and commercial di-tetrabutylammonium cis-bis(isothiocyanato)bis(2,2′-bipyridyl-4,4′-dicarboxylato)ruthenium(II) (N719) dyes were fabricated and characterized based on current–voltage measurements. The effect of the utilization of individual dyes and its mixture, chenodeoxycholic acid as co-adsorbent addition, replacement of I−/I3− by Co2+/3+ ions in electrolyte and platinum by semiconducting polymer mixture poly(3,4-ethylenedioxythiophene) polystyrene sulfonate in counter electrode was studied. Additionally, the effect of polymer thickness on the photovoltaic performance of the device was evaluated. Prepared photoanodes were characterized by UV–Vis spectroscopy and atomic force microscopy. The further modification of DSSCs involving the fabrication of tandem solar cells was carried out. The higher power conversion efficiency 7.60% exhibited tandem photovoltaic cell sensitized with dyes mixture containing co-adsorbent, I−/I3− ions in the electrolyte, and platinum in the electrode.

1. Introduction

Nowadays, due to the substantial demand for electricity and the escalating consumption of fossil fuels, the quest for alternative energy sources holds significant importance. Photovoltaics stands out as one of the fastest-growing sectors within renewables, particularly with the rapid advancement of third-generation solar cells. These cells present numerous opportunities for modifying both the chemical compounds responsible for light absorption and free charge generation, as well as the device structure. Moreover, there is a burgeoning focus on developing efficient photovoltaic cells manufactured on flexible substrates, unveiling new application prospects. Within the realm of third-generation solar cells, often referred to as organic cells, dye-sensitized solar cells (DSSCs) play a significant role [1,2]. The considerable popularity and rapid expansion of DSSCs can be attributed to several advantages, including simple preparation methods, low manufacturing costs, adaptability to various lighting conditions, the ability to be manufactured on flexible substrates, and options for color and transparency. These advantages significantly broaden the potential applications of dye-sensitized solar cells, extending beyond rooftop panels or photovoltaic farms to include uses in building facades or skylights [3,4,5,6]. Obtaining a flexible DSSC cell is possible by using polymeric substrates such as PEN or PET and the properly selected thickness of semiconducting oxide, and it is helpful to reduce the cost of such a cell by using a polymeric counter electrode [7,8]. However, it should be noted that these cells also have their drawbacks and limitations, the main ones being the use of a liquid electrolyte and their relatively low stability and durability over time [9]. Furthermore, the use of a liquid electrolyte containing iodine ions as a redox mediator results in the absorption of a significant portion of solar radiation. Additionally, the low redox potential of this system limits the achievable open-circuit voltage range. Moreover, the presence of the liquid electrolyte significantly contributes to the degradation of the platinum electrode, ultimately reducing the long-term performance of the system. Consequently, extensive research is underway not only to develop new light-absorbing dyes with optimal properties but also to explore modifications in the device structure and the use of new materials for the anode, electrolyte, or counter electrode [10]. As an alternative to iodine ions in the electrolyte, cobalt ions Co2+/3+ can be used, as they are characterized by weak absorption in the visible light range and less aggressiveness towards metallic materials (e.g., counter electrodes) [11]. It is worth bearing in mind that, using a cobalt electrolyte, record efficiencies of around 14% have been achieved for DSSCs [11,12]. The effect of the electrolyte on the Voc value varied depending on the dye used. According to the literature, in the case of dye N719, it is common for Voc to decrease when the iodide pair is replaced by cobalt [13,14,15]. More often, it can be observed that in the case of metal-free dyes, the presence of a cobalt redox pair affects the increase in Voc relative to cells containing an I−/I3− pair, as shown, among other works, in [16,17]. Research is also underway to decrease the overall cost of device fabrication, prompting consideration to substitute the platinum electrode with a polymer material. Furthermore, polymers exhibit increased resistance to corrosion induced by the electrolyte [18,19]. The most commonly used polymers as counter electrode materials include polypyrrole (PPy), polyaniline (PANI), polythiophene (PTh), or poly(3,4-ethylenedioxythiophene) (PEDOT) [20,21,22,23,24]. The use of polymers such as polypyrrole, polyaniline, or PEDOT makes it possible to achieve very high efficiencies often approaching those of cells containing a platinum electrode [25,26,27,28,29]. In the work by Jiao et al. [28], higher PCEs were achieved using CE PANI with a thickness of 1.8 µm (7.27%) than for Pt (7.23%). For DSSCs, the most common dye used is a ruthenium atom-containing dye designated N719 (di-tetrabutylammonium cis-bis(isothiocyanato)bis(2,2′-bipyridyl-4,4′-dicarboxylato)ruthenium(II)). The current record for the efficiency of a device containing the N719 dye is 11.18% [30,31]. It should be borne in mind that there is also intensive research into the use of new, cheaper dyes, among which phenothiazine derivatives play a significant role. DSSC devices containing phenothiazine derivatives achieve high yields of around 10% [32,33,34,35,36,37,38]. Phenothiazine derivatives are noteworthy for their non-planar conformation, which can significantly reduce the degree of dye aggregation when anchoring to an oxide substrate and forming excimers. In addition, they have electron-rich sulphur and nitrogen heteroatoms in their structure, which increases their donor properties and makes them more potent donors than other amines or even triphenylamines, carbazoles, or tetrahydroquinolines [39,40]. The use of a mixture of dye N719 with a phenothiazine derivative allows the absorption range of the photoanode to be extended, which translates mainly into an increase in the photocurrent generated by the solar cell. A second unquestionable advantage of this type of solution is the reduction in the amount of N719 dye used, which translates into a reduction in the cost of preparing the device [41].
The primary objective of this research was to assess the impact of various modifications on DSSC devices. This study provides a concise overview of how these modifications affect systems containing N719, PTZ dyes, or a mixture of both, under consistent experimental conditions. Aligned with current research trends, this study investigates the utilization of a liquid electrolyte containing iodine or cobalt ions alongside a PEDOT:PSS polymer counter electrode. Additionally, the study examines the impact of PEDOT:PSS thickness on the photovoltaic performance of solar cells. The preparation of DSSCs involved utilizing both the commercial N719 and a synthesized metal-free phenothiazine derivative (PTZ), either individually or in combination with the co-adsorbent chenodeoxycholic acid (CDCA). The synthesis process for PTZ was previously detailed in our published paper [38]. The research was completed with the fabrication and characterization of tandem solar cells incorporating, rarely used, the concept of a mixture of dyes in both cells forming the system. On the basis of the research carried out, it was possible to identify the most favorable device structure that provided the highest energy conversion efficiencies. The novelty in the present work is the preparation of tandem cells containing a mixture of dyes, since the vast majority of DSSC tandem cells in the literature had molecules of a single dye present in each of the two cells. Another element of novelty is the use of spray-coating for the preparation of the PEDOT:PSS polymer layers, which allows the preparation of layers with various surface areas, which methods such as spin-coating or drop coating do not quite allow. The research conducted was also aimed at determining the impact of the various modifications under identical photoanode preparation and the same measurement conditions. There are many works available in which individual modifications are studied; however, often due to the use of different preparation conditions, it is not possible to compare the results obtained.

2. Experimental, Materials and Methods

2.1. Experimental

Glass substrates coated with a fluorine doped tin oxide (FTO) layer of approximately 500 nm thick were washed. First, the slides were placed in a beaker with a 10% aqueous surfactant solution (Hellmanex, Hellma Analytics, Müllheim, Germany) and placed in an ultrasonic bath for 15 min at 40 °C. The substrates were then placed in a beaker containing deionized water and again placed in an ultrasound bath for 15 min at 40 °C. This was repeated twice. After this time, the slides were placed in a beaker with isopropanol (IPA) and returned to the ultrasonic bath for 5 min at 40 °C. After removal from the IPA, the substrates were allowed to air-dry. The TiO2 semiconductive layers (18NR-T, Greatcell Solar Materials, Queanbeyan, Australia) were applied to the substrate using screen printing. After the final layer of TiO2 paste was applied and dried, the substrate was heated for 5 min at 125 °C. Substrates with applied layers of TiO2 paste were then annealed at 500 degrees for 30 min. The FTO substrates thus prepared with the applied TiO2 layer were left to cool. The thickness of prepared TiO2 layers was 9 µm. The active area of solar cells every time was 0.56 cm2.
Previously prepared FTO glass substrates with a TiO2 layer were heated to 80 °C and immersed in a dye solution of 3 × 10−4 mol dm−1 for 24 h (with or without 10 mM CDCA). The weight ratio of the mixtures are as follows: PTZ:N719, 0.00025:0.00072 g; PTZ:N719:CDCA, 0.00025:0.00072:0.016 g. After this time, the photoanode was removed from the solution, and the excess of a dye was removed using methanol. The photoanode was left in the air to dry. To prepare the dye solution, a mixture of acetonitrile and tert-butanol (1:1) was used.
A cobalt electrolyte containing bipyridyl and hexafluorophosphate ligands was prepared by weighing 0.129 g (0.001 mol) of cobalt(II) chloride hexahydrate and 0.515 g (0.0033 mol) of 2,2′-bipyridyl and placed in a round-bottom flask. The reactants were dissolved in 0.5 mL of methanol. The resulting solution was heated to the boiling point of the solvent (approximately 65 °C) for 2 h. After this time, excess tetrabutylammonium hexafluorophosphate (TBAPF6) was added to the solution to precipitate the product. The precipitate was filtered and washed successively with methanol, ethanol, and diethyl ether. The obtained precipitate was then dried in a vacuum dryer at 45 °C for 24 h. The product obtained was Co(bpy)3(PF6)2. The cobalt(II) complex was oxidized to the cobalt(III) complex by the addition of perhydrol to an acetonitrile solution containing Co(bpy)3(PF6)2. The prepared solution was stirred for 1 h. An excess of aqueous TBAPF6 solution was then added to precipitate a precipitate, which was filtered and washed with deionized water. Finally, the precipitate was dried under vacuum at 45 °C for 24 h. The product obtained was Co(bpy)3(PF6)3. A liquid electrolyte was prepared by dissolving 0.180 g of Co(bpy)3(PF6)2, 0.048 g of Co(bpy)3(PF6)3, 0.027 g of tert-butylpyridine (TBP), and 0.011 g of LiClO4 in 1 mL acetonitrile.
The platinum counter electrode was prepared on a cleaned FTO slide (washing procedures as for TiO2 application) from a nanoplatin-containing paste using screen printing. After the application of the counter electrode was annealed at 450 °C for 30 min.
The polymer counter electrodes were obtained by applying an aqueous PEDOT:PSS (conductivity: 0.1–1 S cm−1; viscosity: 8–30 mPa s) solution using an airbrush onto clean FTO slides heated to 80 °C. When a homogeneous layer of sufficient thickness was obtained, the temperature was increased to 100 °C and the layer was heated for 15 min.
The DSSC device was constructed by assembling a previously prepared photoanode with a counter electrode, and the space between them was filled with a commercial liquid electrolyte designated as EL-HSE containing I−/I3− ions or prepared electrolyte containing Co2+/3+ ions.
The tandem DSSCs were fabricated based on the reported works [42,43]. The T-DSSCs were constructed by connecting and overlapping two single DSSCs in parallel. The configuration used for calculating PCE 4-terminal.
The dyes N719 and PTZ were desorbed from TiO2 surfaces using a 10 mM aqueous NaOH solution (N719) and a NaOH (0.1 M)–THF mixture (PTZ), respectively. For each of the two dyes, a calibration curve was prepared for solutions with concentrations in the range of 1 × 10−5–8 × 10−5 M and UV–Vis absorption spectra were recorded for them. The desorption of the dyes from the photoanodes was performed by immersing them in the respective solutions for 2 h, until the dye was removed. The complete desorption of the dyes was confirmed by measuring the UV–Vis absorption of the TiO2 substrates after removal from solution. UV–Vis absorption spectra were recorded for the resulting solutions, and concentrations were determined from the calibration curves. The concentration of each solution was then converted to a number of moles. Taking into account the actual active area of the photoanode, the obtained number of moles was converted to 1 cm2.

2.2. Materials and Methods

Fluorine-doped tin oxide coated glass slides (FTOs, 7 Ω/sq, Sigma-Aldrich, St. Louis, MO, USA), 18NR-T titania paste (Greatcell Solar Materials), surfactant (Hellmanex III, Hellma Analytics, Müllheim, Germany), 2-propanol (IPA) (POCH), ruthenium(II)(2,2′-bipyridyl-4,4′-dicarboxylic acid)(2,2′-bipyridyl-4,4′-ditetrabutylammonium carboxylate)-(NCS)2 (N719), and EL-HSE electrolyte were purchased from Sigma-Aldrich. Tert-butyl alcohol (t-BuOH) (Chempur, Karlsruhe, Germany), acetonitrile (Sigma, Wrocław, Poland), and chenodeoxycholic acid (Sigma) were used in device preparation. Cobalt(II) chloride hexahydrate, 2,2′-bipyridyl, and tetrabutylammonium hexafluorophosphate were purchased from Merck, Darmstadt, Germany. PEDOT:PSS was obtained from Ossila, Sheffield, UK. Platisol T/SP was obtained from Solaronix, Aubonne, Switzerland. The synthesis of PTZ was described in the paper [38].
The UV–Vis absorption spectra of TiO2 with adsorbed dyes were recorded using a V-570 UV–Vis–NIR spectrophotometer (Jasco Inc., Tokyo Japan). Electrochemical measurements were performed using a Eco Chemie Autolab PGSTAT128n potentiostat in a one-compartment cell in dichloromethane (Merck, Darmstadt, Germany, for HPLC, 99.8%), with the supporting Bu4NPF6 (Merck, 99%) electrolyte salt with a concentration of 0.1 mol/dm3. A platinum wire (diam. 2.0 mm) served as a working electrode, and the platinum coil and silver wire were used as auxiliary and reference electrode, respectively. Experiments were performed at 23 °C ± 1 °C in an air atmosphere and after a 5 min argon purging. The measurements were recorded with a moderate scan rate equal to 0.1 V/s for cyclic voltammetry and 0.05 V/s for differential pulse voltammetry. Potentials refer to the stable Fc/Fc+ couple with IP = −5.1 eV (ionization potential, EHOMO). EHOMO as ionization potentials and ELUMO as electron affinities are related to HOMO and LUMO energy levels. The nanoscale morphology of the surface of electrodes was characterized by atomic force microscopy (AFM) using a TopoMetrix Explorer device (TopoMetrix, Santa Clara, CA, USA), operating in contact mode, in air, and the constant force regime. The devices were tested using a PV Solutions solar simulator and a Keithley 2400 SourceMeter (Tektronix, Inc., Beaverton, OR, USA) under AM 1.5 G illumination (100 mW cm−2).

3. Results and Discussions

This paper examines the impact of implemented modifications on the ultimate photovoltaic response of the developed DSSCs. The alterations encompassed endeavors to substitute the I−/I3− ion redox pair in the liquid electrolyte with Co2+/3+ ions. Additionally, an effort was made to adopt a polymer counter electrode composed of PEDOT:PSS, replacing Pt. The deposition of polymer layers onto the FTO substrate was notably achieved using the sputtering method from a solution, enabling the coverage of surfaces on a much larger scale than possible in laboratory settings alone. This technique holds potential for automation, ensuring the consistent production of uniform layers with optimal thicknesses suitable for diverse applications and varying sizes in the long term. The study utilized two dyes, namely the commercial N719 and a phenothiazine derivative (PTZ), the synthesis of which has been previously documented [38]. To improve the performance of the prepared devices, co-adsorbent CDCA was also used, the beneficial effects of which were described in our work [41]. The role of the co-adsorbent (CDCA) added to the dye solution is to prevent the formation of aggregates of dye molecules, which significantly reduces unfavorable recombination processes on the photoanode. The chemical structures of the dyes and co-adsorbent are shown in Figure 1.

3.1. UV–Vis Properties of Photoanodes

The study began by determining the absorption properties of the dyes in a mixture of solutions, ACN:t-BuOH (1:1, v:v), as well as the dye molecules anchored to the TiO2 substrate. The recorded absorption spectra in solution and on TiO2 are shown in Figure 2.
Table 1 presents the absorption maxima (λmax) of the dye solutions together with the molar absorption coefficients (ε); in addition, the absorption maxima for the dyes anchored to the TiO2 substrate are also given.
Upon analyzing the absorption spectra captured in the solution, it was noted that the PTZ dye effectively occupied the ‘gap’ within the UV–Vis absorption range of the reference dye N719. This observation led to the presumption that a combination of the two dyes would extend the absorption range, enabling the broader absorption of photons for electron conversion. The absorption spectrum of N719 exhibits three distinctive absorption bands: the band at 310 nm corresponds to the π-π* transition, while the other two (382 and 525 nm) are ascribed to charge transitions from metal to ligand [44]. In addition, the absorption properties of the dye mixture (PTZ and N719) in the solution are presented, and an increase in the molar absorption coefficient with respect to N719 was observed at a range of approximately 425–525 nm, and the absorption range was wider than that of PTZ. Thus, it was concluded that justifying the use of these two dyes as a mixture to enhance the photovoltaic performance of the cell is fully justified. Based on the analysis of the absorption spectra of the individual photoanodes, it was found that the intended goal was achieved: extending the absorption range with respect to PTZ dye and increasing the absorbance of the photoanodes compared to N719.

3.2. Photoanode Morphology

The surface morphology of the prepared photoanodes was determined by the root-mean-square roughness (RMS) determined based on atomic force microscope (AFM). The morphology of the sensitized TiO2 layer has an impact on the photovoltaic parameters of the prepared dye-sensitized solar cells [45]. The RMS values were determined for all prepared photoanodes, which indicated the degree of pore filling by the dye molecules. Selected images taken with an AFM microscope are shown in Figure 3.
The photoanodes with the attached N719 dye exhibited the highest RMS value (52 nm) (Table 2). Conversely, the smaller PTZ dye particles facilitated better pore filling within the TiO2 structure, leading to a significant reduction in the RMS value to 23 nm. Incorporating the dye mixture resulted in a surface roughness with an RMS of 35 nm, which was lower than that of the N719 dye but higher than surfaces with anchored PTZ molecules. The introduction of the CDCA additive caused a slight increase in the RMS value to approximately 37 nm. High RMS can reduce light reflectance, potentially enhancing solar cell performance. Conversely, a more uniform and smoother photoanode surface achieved by filling some pores with dye molecules may improve photovoltaic performance. However, the reduced roughness of the photoelectrodes might impact device stability due to limited oxidant penetration [46].

3.3. Photovoltaic Performance

The final stage of the work carried out was the utilization of fabricated photoanodes for the construction of DSSCs with the following structures: glass/FTO/TiO2@dye/EL-HSE electrolyte/Pt/FTO/glass; glass/FTO/TiO2@dye/Co2+/3+ electrolyte/Pt/FTO/glass; glass/FTO/TiO2@dye/EL-HSE electrolyte/PEDOT:PSS/FTO/glass; and glass/FTO/TiO2@dye/Co2+/3+ electrolyte/PEDOT:PSS/FTO/glass. Figure 4 shows the mechanisms of operation and the energy-level diagrams of the structures of prepared DSSCs.
Modifications of the PV cells by an electrolyte containing cobalt ions and a PEDOT:PSS counter electrode. Photoanodes utilizing pure N719 or PTZ dyes were employed to assess the effect of substituting I−/I3− with cobalt ions. The photocurrent density–voltage characteristics of the fabricated solar cells are depicted in Figure 5. Photovoltaic parameters, derived from the recorded I–V curves, are presented in Table 3. The average values of PV parameters with standard deviations for the three devices.
The substitution of iodine ions with cobalt resulted in a significant decline in device performance. The utilization of an electrolyte with Co2+/3+ ions resulted in decreased photocurrent density and open-circuit voltage in the PV cells. Consequently, the reduced Jsc and Voc values significantly lowered the overall power conversion efficiency (PCE) for N719 and PTZ, dropping to 0.62% and 0.14%, respectively. This decline was primarily attributed to notable differences in charge separation efficiency, evident in the substantial reduction in Jsc values to merely 1.52 mA cm−2 (N719) and 1.91 mA cm−2 (PTZ), directly impacting the increase in charge recombination rates [47]. Likely, the use of a cobalt electrolyte with dyes having long alkyl chains in their structure could produce better results by hindering the recombination process of electrolyte ions and with electrons in the TiO2 layer. For photoanodes containing only N719 or PTZ dyes, the dye loading was determined. Based on the study, N719 dye anchored 2.80 × 10−7 ± 0.3 × 10−7 mol cm−2 and PTZ anchored 3.35 × 10−7 ± 0.42 × 10−7 mol cm−2.
The subsequent phase of the research focused on utilizing polymer counter electrodes. A counter electrode derived from PEDOT:PSS, sputtered onto an FTO-coated glass substrate, was employed, producing a layer with a thickness ranging between 400 and 500 nm. A preliminary investigation was conducted to assess the impact of the PEDOT:PSS layer’s thickness on the photovoltaic performance of the devices. PEDOT:PSS electrodes were prepared with thicknesses of 250 nm and 1500 nm, respectively. The study utilized a solar cell comprising a photoanode with N719 prepared in ACN:t-BuOH. Photovoltaic parameters for devices with counter electrodes of varying thicknesses were subsequently determined. The obtained results are shown in Table 4.
Thus, a significant impact of the polymer layer’s thickness on DSSC efficiency was observed. This highlights the necessity for the comprehensive optimization of the PEDOT:PSS layer thickness in subsequent stages of the study, not limited solely to the N719 dye. Utilizing the polymer electrode primarily led to a reduction in the short-circuit current density compared to the platinum electrode. This fact had the main effect of lowering the PCE values of the devices, although, of course, a decrease in Voc was also seen. For the solar cell containing anchored N719 dye molecules, the Jsc value decreased by 15.28 mA cm−2 and, for the PTZ, by 7.74 mA cm−2, resulting in device efficiencies of 2.05 and 1.57%, respectively.
Further research into the use of the dye mixture with CDCA and PEDOT:PSS (400–500 nm) electrodes was also conducted. As the use of a cobalt redox pair electrolyte gave very low results, this modification was disregarded. Three devices of each type were prepared and the average values of PV parameters, along with the errors, were collected in Table 5. Figure 6 shows the current–voltage curves of selected photovoltaic devices.
DSSCs incorporating a dye mixture with a metallic electrode attained significant efficiencies of 6.87% and 7.10% without and with CDCA, respectively. Ongoing research aiming to substitute both the electrolyte and the metallic counter electrode yielded moderate progress. Nevertheless, this ongoing effort remains focused on enhancing the overall manufacturing process of the device and selecting optimal parameters, such as determining the ideal thickness of the polymer layer. The use of a PEDOT:PSS counter electrode for the mixture also resulted in a decrease in Voc as well as Jsc and FF values, which directly translated into low PCE values relative to the platinum electrode. The use of a polymer electrode resulted in an increase in the resistance value Rso and a decrease in Rhso, which was responsible for the decrease in current density values and FF [48]. Furthermore, interestingly, lower performance values were obtained for the DSSCs with a dye mixture relative to the solar cell with N719, despite the much higher Jsc. The efficiency of the solar cell containing the PTZ:N719 mixture was 1.67%, while that of the N719 reference cell was 2.05%.
Tandem DSSCs. Further research has focused on the preparation of tandem DSSCs (Figure 4). Although papers concerning the preparation of tandem solar cells can be found in the literature [42,43,49,50,51], there are very few publications describing the use of dye mixtures in tandem cells. Consequently, an effort was made to incorporate a dye mixture into this particular type of device, yielding satisfactory and highly promising outcomes. Through the conducted investigations, superior results were achieved compared to individual cells containing a sole dye, suggesting the incomplete absorption of all radiation within the dye’s absorption range. This led to the consideration of utilizing transmitted radiation, prompting the use of a second, identical cell for this purpose. The use of a tandem structure allowed for a significantly higher Jsc value given the way the devices were connected. An increase in Jsc of 2.56 and 4.71 mA cm−2 was obtained for devices without and with the addition of CDCA, respectively. The parameters determined from the current–voltage characteristics allowed the PCE of the tandem cells to be calculated. The implementation of the T-DSSC structure led to an increase of nearly 6% without CDCA and 7% with CDCA, resulting in efficiencies of 7.27% and 7.60%, respectively. The primary goal of this study was to ascertain if employing dye mixtures in a tandem structure enhances device performance. The conducted tests confirmed a notable positive effect using this approach. This ongoing research will persist, focusing on the strategic selection of dyes to optimize the absorption of photons across the broadest possible spectrum.

4. Conclusions

In summary, the findings indicate that for the investigated dyes (PTZ and N719), the utilization of an electrolyte with Co2+/3+ ions notably deteriorated the performance of DSSCs. Similarly, substituting Pt in the counter electrode with PEDOT:PSS resulted in an increase in the series resistance of the cell and a decrease in parallel resistance, primarily manifesting as lower Jsc and FF values. A significant impact of the PEDOT:PSS thickness on DSSC efficiency was evident. Reducing the polymer thickness from 250 to 1500 nm almost doubled the PCE. Optimizing layer thicknesses could enhance cell performance significantly. Notably, sensitizing TiO2 with a metal-free phenothiazine derivative achieved a comparable power conversion efficiency (PCE) of about 6.25% compared to devices based on N719. The subsequent enhancements of approximately 10% and 13% in PCE were achieved through the utilization of a dye mixture and the addition of CDCA to the dye mixture, respectively. Furthermore, presenting the tandem DSSC concept using a dye mixture resulted in a cell exhibiting about 7% higher PCE compared to a single device, marking a novel advancement in this field.

Author Contributions

Conceptualization, P.G. and E.S.-B.; Methodology, P.G.; Formal analysis, P.G.; Investigation, P.G.; Data curation, P.G.; Writing—original draft, P.G. and E.S.-B.; Writing—review & editing, E.S.-B.; Visualization, P.G.; Supervision, E.S.-B. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Data are contained within the article.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Zdyb, A.; Krawczyk, S. Natural Flavonoids as Potential Photosensitizers for Dye-Sensitized Solar Cells. Ecol. Chem. Eng. S 2019, 26, 29–36. [Google Scholar] [CrossRef]
  2. Shakeel Ahmad, M.; Pandey, A.K.; Abd Rahim, N. Advancements in the development of TiO2 photoanodes and its fabrication methods for dye sensitized solar cell (DSSC) applications. A review. Renew. Sustain. Energy Rev. 2017, 77, 89–108. [Google Scholar] [CrossRef]
  3. Goncalves, L.M.; De Zea Bermudez, V.; Ribeiro, H.A.; Mendes, A.M. Dye-sensitized solar cells: A safe bet for the future. Energy Environ. Sci. 2008, 1, 655–667. [Google Scholar] [CrossRef]
  4. Ye, M.; Wen, X.; Wang, M.; Iocozzia, J.; Zhang, N.; Lin, C.; Lin, Z. Recent advances in dye-sensitized solar cells: From photoanodes, sensitizers and electrolytes to counter electrodes. Mater. Today 2015, 18, 155–162. [Google Scholar] [CrossRef]
  5. Song, L.; Du, P.; Xiong, J.; Ko, F.; Cui, C. Efficiency enhancement of dye-sensitized solar cells by optimization of electrospun ZnO nanowire/nanoparticle hybrid photoanode and combined modification. Electrochim. Acta 2015, 163, 330–337. [Google Scholar] [CrossRef]
  6. Barichello, J.; Mariani, P.; Vesce, L.; Spadaro, D.; Citro, I.; Matteocci, F.; Bartolotta, A.; Di Carlo, A.; Calogero, G. Bifacial dye-sensitized solar cells for indoor and outdoor renewable energy-based application. J. Mater. Chem. C 2023, 12, 2317–2349. [Google Scholar] [CrossRef]
  7. Mustafa, M.N.; Sulaiman, Y. Fully flexible dye-sensitized solar cells photoanode modified with titanium dioxide-graphene quantum dot light scattering layer. Sol. Energy 2020, 212, 332–338. [Google Scholar] [CrossRef]
  8. Noorasid, N.S.; Arith, F.; Mustafa, A.N.; Azam, M.A.; Mahalingam, S.; Chelvanathan, P.; Amin, N. Current advancement of flexible dye sensitized solar cell: A review. Optik 2022, 254, 168089. [Google Scholar] [CrossRef]
  9. Li, B.; Wang, L.; Kang, B.; Wang, P.; Qiu, Y. Review of recent progress in solid-state dye-sensitized solar cells. Sol. Energy Mater. Sol. Cells 2006, 90, 549–573. [Google Scholar] [CrossRef]
  10. Mahalingam, S.; Nugroho, A.; Floresyona, D.; Lau, K.S.; Manap, A.; Chia, C.H.; Afandi, N. Bio and non-bio materials-based quasi-solid state electrolytes in DSSC: A review. Int. J. Energy Res. 2022, 46, 5399–5422. [Google Scholar] [CrossRef]
  11. Feldt, S.M.; Gibson, E.A.; Gabrielsson, E.; Sun, L.; Boschloo, G.; Hagfeldt, A. Design of organic dyes and cobalt polypyridine redox mediators for high-efficiency dye-sensitized solar cells. J. Am. Chem. Soc. 2010, 132, 16714–16724. [Google Scholar] [CrossRef] [PubMed]
  12. Kakiage, K.; Aoyama, Y.; Yano, T.; Oya, K.; Fujisawa, J.I.; Hanaya, M. Highly-efficient dye-sensitized solar cells with collaborative sensitization by silyl-anchor and carboxy-anchor dyes. Chem. Commun. 2015, 51, 15894–15897. [Google Scholar] [CrossRef] [PubMed]
  13. Mosconi, E.; Yum, J.H.; Kessler, F.; Gómez García, C.J.; Zuccaccia, C.; Cinti, A.; Nazeeruddin, M.K.; Grätzel, M.; De Angelis, F. Cobalt electrolyte/dye interactions in dye-sensitized solar cells: A combined computational and experimental study. J. Am. Chem. Soc. 2012, 134, 19438–19453. [Google Scholar] [CrossRef] [PubMed]
  14. Marchena, M.J.; De Miguel, G.; Cohen, B.; Organero, J.A.; Pandey, S.; Hayase, S.; Douhal, A. Real-time photodynamics of squaraine-based dye-sensitized solar cells with iodide and cobalt electrolytes. J. Phys. Chem. C 2013, 117, 11906–11919. [Google Scholar] [CrossRef]
  15. Wang, Z.; Xu, H.; Zhang, Z.; Zhou, X.; Pang, S.; Cui, G. High-performance cobalt selenide and nickel selenide nanocomposite counter electrode for both iodide/triiodide and cobalt(II/III) redox couples in dye-sensitized solar cells. Chin. J. Chem. 2014, 32, 491–497. [Google Scholar] [CrossRef]
  16. Shaban, S.; Pradhan, S.; Pandey, S.S. Fabrication and Characterization of Bifacial Dye-Sensitized Solar Cells Utilizing Indoline Dye with Iodine- and Cobalt-Based Redox Electrolytes. Phys. Status Solidi Appl. Mater. Sci. 2023, 220, 2300241. [Google Scholar] [CrossRef]
  17. Yoosuf, M.; Pradhan, S.C.; Sruthi, M.M.; Soman, S.; Gopidas, K.R. Propellar shaped triple bond rigidified D-A-π-A triphenylamine dye as back electron interceptor in iodine and cobalt electrolyte DSSCs under full sun and indoor light. Sol. Energy 2021, 216, 151–163. [Google Scholar] [CrossRef]
  18. Sarkar, A.; Bera, S.; Chakraborty, A.K. CoNi2S4-reduced graphene oxide nanohybrid: An excellent counter electrode for Pt-free DSSC. Sol. Energy 2020, 208, 139–149. [Google Scholar] [CrossRef]
  19. Narudin, N.; Ekanayake, P.; Soon, Y.W.; Nakajima, H.; Lim, C.M. Enhanced properties of low-cost carbon black-graphite counter electrode in DSSC by incorporating binders. Sol. Energy 2021, 225, 237–244. [Google Scholar] [CrossRef]
  20. Saranya, K.; Rameez, M.; Subramania, A. Developments in conducting polymer based counter electrodes for dye-sensitized solar cells—An overview. Eur. Polym. J. 2015, 66, 207–227. [Google Scholar] [CrossRef]
  21. Gnida, P.; Amin, M.F.; Pająk, A.K.; Jarząbek, B. Polymers in High-Efficiency Solar Cells: The Latest Reports. Polymers 2022, 14, 1946. [Google Scholar] [CrossRef]
  22. Ding, S.; Yang, C.; Yuan, J.; Li, H.; Yuan, X.; Li, M. An overview of the preparation and application of counter electrodes for DSSCs. RSC Adv. 2023, 13, 12309–12319. [Google Scholar] [CrossRef] [PubMed]
  23. Richhariya, G.; Kumar, A.; Shukla, A.K.; Shukla, K.N.; Meikap, B.C. Effect of Different Counter Electrodes on Power Conversion Efficiency of DSSCs. J. Electron. Mater. 2023, 52, 60–71. [Google Scholar] [CrossRef]
  24. Nurazizah, E.S.; Aprilia, A.; Risdiana, R.; Safriani, L. Different Roles between PEDOT:PSS as Counter Electrode and PEDOT:Carrageenan as Electrolyte in Dye-Sensitized Solar Cell Applications: A Systematic Literature Review. Polymers 2023, 15, 2725. [Google Scholar] [CrossRef] [PubMed]
  25. Khan, S.A.; Li, L.; Zhao, D.; Chen, S. Increased power conversion efficiency of dye-sensitized solar cells with counter electrodes based on porous polypyrrole. React. Funct. Polym. 2020, 148, 104483. [Google Scholar] [CrossRef]
  26. Sangiorgi, N.; Sangiorgi, A.; Tarterini, F.; Sanson, A. Molecularly imprinted polypyrrole counter electrode for gel-state dye-sensitized solar cells. Electrochim. Acta 2019, 305, 322–328. [Google Scholar] [CrossRef]
  27. Karakuş, M.Ö.; Yakışıklıer, M.E.; Delibaş, A.; Ayyıldız, E.; Çetin, H. Anionic and cationic polymer-based quasi-solid-state dye-sensitized solar cell with poly(aniline) counter electrode. Sol. Energy 2020, 195, 565–572. [Google Scholar] [CrossRef]
  28. Jiao, S.; Wen, J.; Zhou, Y.; Sun, Z.; Liu, Y.; Liu, R. Preparation and Property Studies of Polyaniline Film for Flexible Counter Electrode of Dye-Sensitized Solar Cells by Cyclic Voltammetry. ChemistrySelect 2021, 6, 230–233. [Google Scholar] [CrossRef]
  29. Pradhan, S.C.; Soman, S. Effect of thickness on charge transfer properties of conductive polymer based PEDOT counter electrodes in DSSC. Results Surf. Interfaces 2021, 5, 100030. [Google Scholar] [CrossRef]
  30. Nazeeruddin, M.K.; De Angelis, F.; Fantacci, S.; Selloni, A.; Viscardi, G.; Liska, P.; Ito, S.; Takeru, B.; Grätzel, M. Combined experimental and DFT-TDDFT computational study of photoelectrochemical cell ruthenium sensitizers. J. Am. Chem. Soc. 2005, 127, 16835–16847. [Google Scholar] [CrossRef]
  31. Di Cheng, J.; He, C.X.; Chen, D.; Gu, X.Y.; Wang, S.K.; Gao, X.P.; Sun, G.Z.; Zhang, Z.X.; Pan, X.J.; Pan, X.B.; et al. Effect of ruthenium(II)-bipyridine complex photosensitizer on the panchromatic light absorption and electron transfer in N719-dye sensitized photoanodes. Opt. Mater. 2022, 133, 112924. [Google Scholar] [CrossRef]
  32. Hua, Y.; Chang, S.; Huang, D.; Zhou, X.; Zhu, X.; Zhao, J.; Chen, T.; Wong, W.Y.; Wong, W.K. Significant improvement of dye-sensitized solar cell performance using simple phenothiazine-based dyes. Chem. Mater. 2013, 25, 2146–2153. [Google Scholar] [CrossRef]
  33. Marszalek, M.; Nagane, S.; Ichake, A.; Humphry-Baker, R.; Paul, V.; Zakeeruddin, S.M.; Grätzel, M. Tuning spectral properties of phenothiazine based donor-π-acceptor dyes for efficient dye-sensitized solar cells. J. Mater. Chem. 2012, 22, 889–894. [Google Scholar] [CrossRef]
  34. Hua, Y.; Chang, S.; He, J.; Zhang, C.; Zhao, J.; Chen, T.; Wong, W.Y.; Wong, W.K.; Zhu, X. Molecular engineering of simple phenothiazine-based dyes to modulate dye aggregation, charge recombination, and dye regeneration in highly efficient dye-sensitized solar cells. Chem. A Eur. J. 2014, 20, 6300–6308. [Google Scholar] [CrossRef]
  35. Lin, R.Y.Y.; Wu, F.L.; Li, C.T.; Chen, P.Y.; Ho, K.C.; Lin, J.T. High-Performance Aqueous/Organic Dye-Sensitized Solar Cells Based on Sensitizers Containing Triethylene Oxide Methyl Ether. ChemSusChem 2015, 8, 2503–2513. [Google Scholar] [CrossRef] [PubMed]
  36. Slodek, A.; Zych, D.; Szafraniec-Gorol, G.; Gnida, P.; Vasylieva, M.; Schab-Balcerzak, E. Investigations of new phenothiazine-based compounds for dye-sensitized solar cells with theoretical insight. Materials 2020, 13, 2292. [Google Scholar] [CrossRef]
  37. Slodek, A.; Zych, D.; Golba, S.; Zimosz, S.; Gnida, P.; Schab-Balcerzak, E. Dyes based on the D/A-acetylene linker-phenothiazine system for developing efficient dye-sensitized solar cells. J. Mater. Chem. C 2019, 7, 5830–5840. [Google Scholar] [CrossRef]
  38. Fabiańczyk, A.; Gnida, P.; Chulkin, P.; Kula, S.; Filapek, M.; Szlapa-Kula, A.; Janeczek, H.; Schab-Balcerzak, E. Effect of heterocycle donor in 2-cyanoacrylic acid conjugated derivatives for DSSC applications. Sol. Energy 2021, 220, 1109–1119. [Google Scholar] [CrossRef]
  39. Luo, J.S.; Wan, Z.Q.; Jia, C.Y. Recent advances in phenothiazine-based dyes for dye-sensitized solar cells. Chinese Chem. Lett. 2016, 27, 1304–1318. [Google Scholar] [CrossRef]
  40. Tian, H.; Yang, X.; Chen, R.; Pan, Y.; Li, L.; Hagfeldt, A.; Sun, L. Phenothiazine derivatives for efficient organic dye-sensitized solar cells. Chem. Commun. 2007, 36, 3741–3743. [Google Scholar] [CrossRef]
  41. Gnida, P.; Libera, M.; Pająk, A.; Schab-Balcerzak, E. Examination of the Effect of Selected Factors on the Photovoltaic Response of Dye-Sensitized Solar Cells. Energy Fuels 2020, 34, 14344–14355. [Google Scholar] [CrossRef]
  42. Eom, Y.K.; Kang, S.H.; Choi, I.T.; Yoo, Y.; Kim, J.; Kim, H.K. Significant light absorption enhancement by a single heterocyclic unit change in the π-bridge moiety from thieno[3,2-b]benzothiophene to thieno[3,2-b]indole for high performance dye-sensitized and tandem solar cells. J. Mater. Chem. A 2017, 5, 2297–2308. [Google Scholar] [CrossRef]
  43. Yanagida, M.; Onozawa-Komatsuzaki, N.; Kurashige, M.; Sayama, K.; Sugihara, H. Optimization of tandem-structured dye-sensitized solar cell. Sol. Energy Mater. Sol. Cells 2010, 94, 297–302. [Google Scholar] [CrossRef]
  44. Song, L.; Du, P.; Shao, X.; Cao, H.; Hui, Q.; Xiong, J. Effects of hydrochloric acid treatment of TiO2 nanoparticles/nanofibers bilayer film on the photovoltaic properties of dye-sensitized solar cells. Mater. Res. Bull. 2013, 48, 978–982. [Google Scholar] [CrossRef]
  45. Wang, X.; Bolag, A.; Yun, W.; Du, Y.; Eerdun, C.; Zhang, X.; Bao, T.; Ning, J.; Alata, H.; Ojiyed, T. Enhanced performance of dye-sensitized solar cells based on a dual anchored diphenylpyranylidene dye and N719 co-sensitization. J. Mol. Struct. 2020, 1206, 127694. [Google Scholar] [CrossRef]
  46. Atli, A.; Atilgan, A.; Yildiz, A. Multi-layered TiO2 photoanodes from different precursors of nanocrystals for dye-sensitized solar cells. Sol. Energy 2018, 173, 752–758. [Google Scholar] [CrossRef]
  47. Gierszewski, M.; Grądzka, I.; Glinka, A.; Ziółek, M. Insights into the limitations of solar cells sensitized with ruthenium dyes revealed in time-resolved spectroscopy studies. Phys. Chem. Chem. Phys. 2017, 19, 20463–20473. [Google Scholar] [CrossRef]
  48. Yun, D.J.; Ra, H.; Rhee, S.W. Concentration effect of multiwalled carbon nanotube and poly(3, 4-ethylenedioxythiophene) polymerized with poly(4-styrenesulfonate) conjugated film on the catalytic activity for counter electrode in dye sensitized solar cells. Renew. Energy 2013, 50, 692–700. [Google Scholar] [CrossRef]
  49. Ooyama, Y.; Harima, Y. Photophysical and electrochemical properties, and molecular structures of organic dyes for dye-sensitized solar cells. ChemPhysChem 2012, 13, 4032–4080. [Google Scholar] [CrossRef]
  50. Kang, S.H.; Jeong, M.J.; Eom, Y.K.; Choi, I.T.; Kwon, S.M.; Yoo, Y.; Kim, J.; Kwon, J.; Park, J.H.; Kim, H.K. Porphyrin Sensitizers with Donor Structural Engineering for Superior Performance Dye-Sensitized Solar Cells and Tandem Solar Cells for Water Splitting Applications. Adv. Energy Mater. 2017, 7, 1602117. [Google Scholar] [CrossRef]
  51. Xiong, D.; Chen, W. Recent progress on tandem structured dye-sensitized solar cells. Front. Optoelectron. 2012, 5, 371–389. [Google Scholar] [CrossRef]
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Figure 1. The chemical structures of used dyes: (a) N719 and (b) PTZ, (c) co-adsorbent–chenodeoxycholic acid (CDCA).
Figure 1. The chemical structures of used dyes: (a) N719 and (b) PTZ, (c) co-adsorbent–chenodeoxycholic acid (CDCA).
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Figure 2. The registered UV–Vis absorption spectra of (a) dye solutions in ACN:t-BuOH (C = 3 × 10−5 mol dm−3) and (b) dyes anchored to TiO2 surfaces.
Figure 2. The registered UV–Vis absorption spectra of (a) dye solutions in ACN:t-BuOH (C = 3 × 10−5 mol dm−3) and (b) dyes anchored to TiO2 surfaces.
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Figure 3. The selected AFM micrographs of photoanodes with anchored (a) N719; (b) PTZ:N719; and (c) PTZ:N719:CDCA.
Figure 3. The selected AFM micrographs of photoanodes with anchored (a) N719; (b) PTZ:N719; and (c) PTZ:N719:CDCA.
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Figure 4. (a) Scheme of the DSSCs structure and (b) diagram showing the principle of operation, (c) energy-level diagram, and (d) scheme of tandem dye-sensitized solar cell.
Figure 4. (a) Scheme of the DSSCs structure and (b) diagram showing the principle of operation, (c) energy-level diagram, and (d) scheme of tandem dye-sensitized solar cell.
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Figure 5. Photocurrent density–voltage characteristics of fabricated devices (a) with anchoring N719 and (b) PTZ molecules.
Figure 5. Photocurrent density–voltage characteristics of fabricated devices (a) with anchoring N719 and (b) PTZ molecules.
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Figure 6. Photocurrent density–voltage characteristics of selected solar cells.
Figure 6. Photocurrent density–voltage characteristics of selected solar cells.
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Table 1. UV–Vis properties of dye solutions and photoanodes.
Table 1. UV–Vis properties of dye solutions and photoanodes.
DyeACN:t-BuOHTiO2
λmax [nm] (ε [dm3 mol−1 cm−1])λmax [nm]
N719218 (26,333),
250 sh (16,000),
312 (20,667),
388 (6000),
532 (6333)		405,
541
PTZ216 (6667),
234 (6500),
316 (15,000),
468 (7333)		382,
485
PTZ:N719218 (22,000),
250 sh (14,667),
314 (23,333),
404 (6000),
464 (6667),
534 (5333)		477,
540 sh
PTZ:N719:CDCA̶375,
475
sh—shoulder.
Table 2. RMS values of prepared photoanodes.
Table 2. RMS values of prepared photoanodes.
DyesRMS [nm]
N71952
PTZ23
PTZ:N71935
PTZ:N719:CDCA37
Table 3. Photovoltaic parameters of fabricated DSSCs devices.
Table 3. Photovoltaic parameters of fabricated DSSCs devices.
DyeElectrolyteCounter
Electrode		Voc
[mV]		Jsc
[mA cm−2]		FFPCE
[%]
N719I−/I3−Pt723 ± 1020.19 ± 0.210.42 ± 0.026.29 ± 0.05
I−/I3−PEDOT:PSS659 ± 54.91 ± 0.070.60 ± 0.012.05 ± 0.04
Co2+/3+Pt620 ± 131.52 ± 0.090.64 ± 0.020.62 ± 0.03
Co2+/3+PEDOT:PSS639 ± 121.05 ± 0.060.70 ± 0.010.45 ± 0.02
PTZI−/I3−Pt701 ± 1116.84 ± 0.120.50 ± 0.016.25 ± 0.04
I−/I3−PEDOT:PSS570 ± 89.10 ± 0.150.24 ± 0.021.55 ± 0.05
Co2+/3+Pt204 ± 121.91 ± 0.060.36 ± 0.010.14 ± 0.01
Co2+/3+PEDOT:PSS190 ± 100.52 ± 0.030.40 ± 0.010.04 ± 0.01
Table 4. Photovoltaic parameters of solar cells (N719) with PEDOT:PSS CEs of various thicknesses.
Table 4. Photovoltaic parameters of solar cells (N719) with PEDOT:PSS CEs of various thicknesses.
Thickness [nm]Voc [mV]Jsc [mA cm−2]FFPCE [%]
250657 ± 810.31 ± 0.150.25 ± 0.011.73 ± 0.01
500659 ± 54.91 ± 0.070.60 ± 0.012.05 ± 0.04
1500524 ± 35.01 ± 0.100.35 ± 0.020.92 ± 0.03
Table 5. The photovoltaic performance of solar cells containing a mixture of dyes.
Table 5. The photovoltaic performance of solar cells containing a mixture of dyes.
DyeCounter
Electrode		Voc
[mV]		Jsc
[mA cm−2]		FFPCE
[%]
PTZ:N719Pt740 ± 719.49 ± 0.080.46 ± 0.016.87 ± 0.06
PEDOT:PSS564 ± 910.66 ± 0.100.30 ± 0.011.67 ± 0.04
PTZ:N719:CDCAPt791 ± 617.44 ± 0.050.51 ± 0.027.10 ± 0.03
PEDOT:PSS544 ± 1011.04 ± 0.090.32 ± 0.021.99 ± 0.02
PTZ:N719 (T-DSSC)Pt715 ± 2022.05 ± 0.430.45 ± 0.037.27 ± 0.26
PTZ:N719:CDCA
(T-DSSC)		Pt720 ± 2422.15 ± 0.680.46 ± 0.057.60 ± 0.38
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Gnida, P.; Schab-Balcerzak, E. Effect of Structural and Material Modifications of Dye-Sensitized Solar Cells on Photovoltaic Performance. Coatings 2024, 14, 837. https://doi.org/10.3390/coatings14070837

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Gnida P, Schab-Balcerzak E. Effect of Structural and Material Modifications of Dye-Sensitized Solar Cells on Photovoltaic Performance. Coatings. 2024; 14(7):837. https://doi.org/10.3390/coatings14070837

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Gnida, Paweł, and Ewa Schab-Balcerzak. 2024. "Effect of Structural and Material Modifications of Dye-Sensitized Solar Cells on Photovoltaic Performance" Coatings 14, no. 7: 837. https://doi.org/10.3390/coatings14070837

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