ISSN: 2456–5474 RNI No.  UPBIL/2016/68367 VOL.- VIII , ISSUE- X November  - 2023
Innovation The Research Concept

Modification of Photoelectrochemical Properties of Eco-Friendly Dye-Sensitized Solar Cells
Paper Id :  18293   Submission Date :  2023-11-11   Acceptance Date :  2023-11-22   Publication Date :  2023-11-25
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DOI:10.5281/zenodo.10349608
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Divya Jyoti
Assistant Professor
Department Of Physics
University College,
Jaito,Punjab, India
Ruchika Seth
Assistant Professor
Chemistry
University College,
Jaito, Punjab, India
Abstract

Dye-sensitized solar cells have been fabricated using TiO2 thin films coated by using sol-gel dip coating technique. Performance of dye-sensitized solar cells have been explored in terms of variation of evaporation temperature at which sol is concentrated and the amount of PEG (Polyehtylene glycol) added to the sol. Film thickness has been found to increase with addition of PEG but efficiency increases up to 40% by weight of TiO2 and decreases afterwards. Thickness has been tailored by multiple coating technique. It has been observed that conversion efficiency decreases with increase in evaporation temperature. A comparatively higher value of photocurrent has been observed with the sol concentrated at 40OC than at room temperature.
Keywords Evaporation Temperature, Absorbance, Thickness, Photocurrent.
Introduction

The pursuit of environmentally benign and efficient means of producing energy has motivated the researchers to work in the field of renewable energy sources [1-2]. Solar technologies pave way to reduce world’s over dependence on fossil fuels. Solar cells harness the clean and abundant energy of sun in an eco-friendly way by directly converting sunlight in to electricity. Present study is focused on dye-sensitized solar cells (DSSCs) also called Gratzel cells [3, 4].

A typical DSSC is composed of a few micrometer thick film consisting of metal oxide covered with a monolayer of dye, a redox electrolyte and a platinum metal electrode. One of the key components of DSSCs is semiconductor oxide electrode. Light absorption occurs in dye molecules adsorbed on porous semiconductor (TiO2) layer. Dye excitation is followed by electron injection in TiO2 and regeneration via a redox couple electrolyte. Much effort has gone into the study of different methods to synthesize semiconductor electrode film [5, 6]. Sol-gel technique may also allow more precise control of film thickness, particle size and porosity by controlling different parameters viz. concentration of sol, spin speed and annealing temperature [7-10]. We have attempted sol-gel dip coating process for the synthesis of TiO2 films. Presented work reports the effects of variation of temperature at which sol is concentrated. Thickness of the films is varied by multiple coatings. Multiple coating methods help to have a better control over the thickness of thin film acting as photoanode in dye-sensitized solar cells that presents an efficient tool to enhance the light harvesting performance of the cell.
Objective of study

In the present course of investigations, the effect of evaporation temperature is studied to get a better understanding of performance parameters of dye-sensitized solar cells. Experimental details and results are given in following sections.
Review of Literature

Review of Literature mentioned in the text along with main text.
Main Text

The semiconductor electrode films were deposited by sol-gel dip coating technique with the help of Titanium iso-propoxide (TTIP) precursor and poly ethylene glycol (PEG) as thickness controller as reported in earlier studies [11]. Multiple coatings were used to obtain films of different thicknesses 1.2, 2.3, 3.5, 4.4 µm. The crystalline structure of the films was characterized by x-ray diffraction (XRD).

Ru(II) based N719 dye was adsorbed on to TiO2 surface by immersing it into dye solution. A platinized ITO (indium tin oxide) coated glass was used as counter electrode. Inter-electrode space was filled by redox electrolyte. Current-voltage (I-V) characteristics of the cells under one sun illumination were recorded using a solar simulator.
Methodology
Multiple coating technique.
Tools Used Solar Simulator.
Result and Discussion

Figure 1 displays XRD result for the synthesized TiO2 film and it is very clear that films formed are in pure anatase form. Each peak in the spectrum can be indexed in terms of unique crystalline planes of anatase allotropic form of TiO2.


Figure 1. XRD spectra of formed TiO2 films

Figure 2 depicts the variation in absorbance of the films after dye adsorption with film thickness at 518 nm wavelength of light together with the theoretical results using Lambert-Beers law [12]. It is clear that dye absorption increases linearly with thickness but decreases slightly at higher thickness.

 

Figure 2. Variation in absorbance of TiO2 thin films covered with dye

Figure 3 shows the change in short-circuit current (ISC) of the cells with film thickness. ISC first increases with the thickness of the electrode film and then gets a slight decrease in its values. Increased film thickness leads to adsorption of more number of dye molecules thereby increasing photocurrent but afterwards decrease in its values may be attributed due to increased series resistance of thicker films.


Figure 3. Change in ISC values of the fabricated cells with film thickness

Short-circuit current (ISC) values are found to decrease linearly with evaporation temperature at which sols have been concentrated as shown in figure 4.


Figure 4. Variation in ISC values of the cells with change in evaporation temperature

This may be explained on the basis of increased degree of agglomeration and hence lower porosity at higher temperature owing to faster evaporation rate.
Findings

It may be predicted that a moderate film thickness along with not higher evaporation temperature is best suited for utmost performance in Dye-sensitized solar cells.
Conclusion

Anatase TiO2 based dye-sensitized solar cells have been synthesized and effects of evaporation temperature and film thickness on the cell performance have been studied. It has been found that film thickness increases with the addition of PEG but ISC first increases followed by a slight steadiness with increase in thickness. An opposite trend has been observed with evaporation temperature due to agglomeration at higher temperatures because of faster rate of evaporation. It may be predicted that a moderate film thickness along with not higher evaporation temperature is best suited for utmost performance in Dye-sensitized solar cells. It may be predicted that a moderate film thickness along with not higher evaporation temperature is best suited for utmost performance in Dye-sensitized solar cells.
References

1. S. Rahman, A. Haleem, M. Siddiq, M. K. Hussain, S. Qamar, S. Hameed and M. Waris, Research on Dye-Sensitized Solar Cells: recent advancement toward the various constituents of dye sensitized solar celss for efficiency enhancement and future prospects, Royal Society of Chemistry, Research Advances, 2023, Vol. 13, pp 19508-19529.

2. David Fridley, Nine challenges of Alternative Energy, 2010.

3. B. O. Regan, M. Gratzel, Photoelectrochemical Solar cells, Nature, 1991, Vol. 353, pp 737-742.

4. Michael Grätzel, Solar Energy Conversion by Dye-Sensitized Photovoltaic Cells, Inorg. Chem. 2005, Vol. 44 (20), pp 6841–6851.

5.  N.G. Renganathan, M. Venkata Subramanian and S. Mohan, Electrodeposition route to synthesize Cigs films-an economical way to harness solar energy, International Journal of Engineering, Science and Technology, 2011, Vol. 3, No. 1, pp. 206-212.

6.  S. N. Sahu and K. K. Nanda, Nanostructure Semiconductors: Physics and Applications, PINSA, 2001, 67A(1), pp. 103-130.

7. A. Beganskiene, S. Sakirzanovas, I. Kazadojev, A. Melninkaitis, V. Sirutkaitis, A. Kareiva, Sol gel derived anti reflective coating with controlled thickness and refractive index, Materials Science-Poland, 2007, Vol. 25, No. 3, pp. 817-824.

8. S. Bandyopadhyay, G.K. Paul, S.K. Sen, Study of optical properties of some sol gel derived films of ZnO, Solar Energy Materials a Solar Cells, 2002, 71, pp. 103–113.

9. Qian Chen, Juha Larismaa, Anu Keski-honkola, Kati Vilonen, Outi Söderberg, Simo-Pekka Hannula, Effect of Synthesis Time on Morphology of Hollow Porous Silica Microspheres, MATERIALS SCIENCE, 2012, Vol. 18, No. 1, pp. 66-71.

10. Antonio Tricoli ,  Anna S. Wallerand and Marco Righettoni, Highly porous TiO2 films for dye sensitized solar cells , J. Mater. Chem., 2012, 22, pp. 14254-14261.

11. Divya Jyoti, Devendra Mohan and Rakesh Dhar, Investigation of Transport and Optical Properties of Mesoporous Anatase and Rutile TiO2 Films for Application in Dye-Sensitized Solar cells, Modern physics Letters B, 2012, Vol 26(19), pp. 1250123-8 pages.

12. B. Stuart, Modern Infrared Spectroscopy, Wiley, England, 1996.