Elsevier

Optical Materials

Volume 111, January 2021, 110658
Optical Materials

Performance evaluation of mixed synthetic organic dye as sensitizer based dye sensitized solar cell

https://doi.org/10.1016/j.optmat.2020.110658Get rights and content

Highlights

  • Co-sensitized DSSC was obtained using bromophenol and eosin Yin 1:1 ratio.

  • SEM, EDS and XRD analysis were observed to analyze structure of TiO2.

  • EIS, UV -Vis spectra, performance parameters were studied for mixed DSSC.

  • The mixed dye exhibiting good device performance.

  • High electrocatalytic activityprovide sufficiently low cost dye for ruthenium free DSSCs.

Abstract

A combination of two synthetic organic dyes, namely eosin Y and bromophenol were utilized as a novel category of dye for dye-sensitized solar cells (DSSCs). XRD study revealed the anatase form of titanium dioxide. SEM showed roughly spherical and non-homogenous nature of particles. Energy dispersive spectroscopy (EDS) spectrum analysis showed no impurity in TiO2 and ZnO, thus revealing purity in photo electrode materials. The absorbance of dyes was observed by using UV–Vis absorbance spectroscopy. The dyes showed absorbance from visible to near infra red region. Electrochemical impedance spectroscopy (EIS) measures dye solar cell internal resistance. The performance of photovoltaic cells was studied under 100 mW/cm2 illumination. An enhancement in the power conversion was achieved by using mixed dye (2.31%) that is much higher than single dyed cell (1.62%; eosin Y). The mixed dye exhibiting good device performance and high electrocatalytic activity can provide a sufficiently low cost dye for ruthenium free DSSCs.

Introduction

The continually rising requirement in delivering energy has been increased the depletion of vestige energy. It is expected that fossil fuel assets all around the globe may just be preceding 40 years for oil, 60 years for natural gas and 200 years for coal [1]. The forthcoming exhaustion has encouraged the improvement of sustainable resources technologies. The photovoltaic is a unique technology among the various renewable energy technologies that convert sunlight into electricity. However, commercial solar cells are restricted because of uneconomical assembly as well as environmental prices. On the other side, DSSCs show potential for electricity generation and have many aspects such as low-priced photovoltaic devices due to modest materials and easy fabrication techniques. Usually, a dye solar cell contains a transparent conductive oxide (TCO) as a substrate for anode and cathode, titanium dioxide film deposited onto transparent conductive oxide glass, a sensitizer adsorbed onto the plane of the semiconductor layer, a volatile electrolyte and a counter electrode [[2], [3], [4], [5], [6]] as shown in Fig. 1a.

Compared with other photovoltaic cells, the DSSCs have shown distinctive characteristics such as low fabrication cost, flexibility (with flexible substrates), have different colors that can work under diffused light conditions [[7], [8], [9], [10], [11], [12]]. The energy flow diagram of dye solar cell is revealed in Fig. 1 (b). Whenever sun rays hit onto dye molecules, they generated energized electrons into the conduction band (CB) semiconductor. These electrons pass through the anode and arrive at the electrical load [[13], [14], [15], [16], [17], [18]].

A dye is the main element liable to determine cell efficiency. The photon energized sensitizer is required to have the ability to instigate electrons into the CB of the semiconductor [[19], [20], [21]]. The sensitizer is a prominent element that is essential for additional enhancement in their photon-penetration efficiency. It is a prompt study in the field toward the enhancement of dye. Consequently, widespread studies have been investigated in the field of useful dyes. The ruthenium complexes (N719) reported a 6.86% conversion efficiency of the cell with standard illumination conditions [22]. The co-sensitized solar cells have obtained additional consideration due to the capability of energy conversion method by absorbing photons from visible to near-infrared region of solar spectrum of radiation. The TiO2 electrodes was co sensitized with N719 and PbS/CdS core-shell quantum dots showed notably higher efficiency of 4.41% [23]. A dye solar cell was co sensitized with a ruthenium (II) based dye (N749), and an organic sensitizer (RK1) attained a PCE of 8.15% [24]. The less availability of ruthenium metal results in the high cost of the dye. Alternatively, metal-free organic dyes were studied: eosin Y, methyl violet, carbol fuschin, Bromophenol, Methyl orange, etc. Eosin Y has shown efficiency of 2.4% [25]. Usually, a DSSC has TiO2 coated working electrode and a layer of a single dye is adsorbed onto the surface of the semiconductor. However, the application of two or more dyes can raise the absorbance on the broader range solar spectrum. N719 organic dye and CdSe quantum dots (CdSe-QDs) were used to sensitize TiO2 photoanode. This novel configuration achieved around a 37% enhancement of the photovoltaic efficiency compared to the cell when sensitized N719 dye alone [26]. A new dye W2 with double anchor was developed to investigate the co-sensitizing capability of 2,6-diphenyl-4H-pyranylidene (DP) dye. Co sensitized solar cell using N719 with W2 dye exhibited superior photocurrent compared to the reference N719 dye, resulting in PCE from 7.77% to 8.20% [27]. After focusing the entire mentioned results, it assure the favor of the present performance. Firstly, observe appropriate synthetic organics as well as scrutinize the performance for TiO2 and ZnO coated electrodes. Secondly, to examine mixed dye solar cell performance, either it would be valuable for DSSC application. The cocktail sensitizer showed an extensive absorbance in the UV Visible spectrum region that reveals the transition of electron charges. Consequently, via examining overall aspects, and bromophenol and eosin dyes are taken and photovoltaic performance is noticed by proceeding single along with assorted dye.

Section snippets

Materials and equipment

Bromophenol and eosin Y (metal-free organic sensitizer) were obtained from J&K (India), Titanium dioxide (semiconductor), Iodolyte (electrolyte), Fluorine doped tin oxide (FTO) having sheet resistance = 21.1Ω/sq., Polyethylene glycol 400 {HO (C2H4O)}were taken from Solaronix Company (India). Other chemicals and solvents were bought from local suppliers. Ethanol was used for the extraction of all dyes, and all chemicals are of analytic grade. XRD analysis was done using X-ray diffractometer

SEM and EDS results

The main point for the application of DSSC is the surface morphology. Thus it is remarkable to examine the surface morphology of TiO2 and ZnO nanoparticle. SEM was used to study the morphology of semiconductors. It gives the shape and size of TiO2 and ZnO nanoparticles. Roughly spherical and non-homogenous particles have been observed, as shown in Fig. 2 (a - b). SEM image is showing particles of nano sized of generation throughout the facet. Fig. 2 (e & f) reveals the EDS spectrum of ZnO and

Conclusion

It is realized that assorted dye showed a feasible absorption response in the visible expansion of solar spectra. Notably, titanium dioxide based assorted DSSC gave a more comprehensive absorption range (i.e., 420–540 nm). At last, the mixed dye sensitized cell revealed a PCE of 2.31%. A higher photocurrent was noticed in the case of the mixing of bromophenol with eosin Yin comparison to single DSSC. Therefore, it is concluded that the assorted dye solar cell is innumerably favorable. The

CRediT authorship contribution statement

Geetam Richhariya: Conceptualization, Methodology, Software, Data curation, Writing - original draft. Anil Kumar: Visualization, Investigation, Supervision, Writing - review & editing.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgment

The authors are highly thankful to the Centre for Energy and Environment, Delhi Technological University and Energy Centre, Maulana Azad National Institute of Technology, Bhopal, for providing all facilities for performing this research work.

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