Anthocyanin from Basella alba (Alugbati) stems as light-accumulators for making of dye-sensitized solar cells
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An Investigatory Project Presented to
Association of Science Educators of the Philippines (ASEP) in cooperation with
Department of Education (DepEd)
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As an Entry to the
2014 REGIONAL SCIENCE QUEST
(Regional Level – Physical Science Team – Private Schools Category)
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Proponents
Dan Carlos C. Calubaquib
Lisa Marielle S. Tagasa
Rea Melissa P. Espiritu
EFREN PAZ
Research Adviser
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Roosevelt College Science High School
Sumulong Highway Cainta, Rizal
November 2014

ACKNOWLEGDEMENT

We would like to thank our parents for their nonstop support during our research project. Thank you for Mr. and Mrs. Tagasa for letting us stay at their house to do our experiments in the middle of the night. Thanks you for Mrs. Espiritu for helping us to find Indium Tin Oxide, which is essential to our study. And last but not the least, thank you for Ms. Corpuz for helping us to find the chemicals we needed. To our friends that encouraged us to continue. Thank you for Austin Kinn Rubin for giving us a piece of advice on what would be the best thing to do for our research. And to the entire Batch 10, we thank you for the support you gave. To our teachers that taught us how to think and not what to think. To Ms. Luzita Alcid, our principal, who helped us defend our study better. To our research teacher, Mr. Paz, who helped in proofreading our study. To Ms. Jen Cayetano, who helped us in correcting our grammar over the course of the study.
And lastly, thank you for the guidance of the Almighty God. We would like to thank him for the wisdom and knowledge he gave us so that we can do this study. Without him all of this would not have been possible.

D.C.C.C. L.M.S.T.
R.M.P.E.

ABSTRACT
This study investigated on the potential of Anthocyanin as a light-attenuator for dye-sensitized solar cells (DSSC). The production of DSSC is cheaper than conventional solar cells.
In this research we used Anthocyanin extracted from Basella alba (Alugbati) as dye for making dye-sensitized solar cells. The dye-sensitized solar cells were made from Indium Tin oxide glass smeared with TiO2 paste, Acetic acid, liquid detergent. The paste was dyed with Anthocyanin extract from Alugbati. It was then combined with another Indium Tin Oxide glass with soot and electrolyte shuttle.
DSSCs dyed with Alugbati Anthocyanin extract yields about 0.140V-0.170V, depending on the concentration of the Anthocyanin.

CHAPTER I
INTRODUCTION

1. Background of the study

A lot of alternative sources of energy are being used to generate cleaner, greener, cheaper. The use of solar cells is common to generate electricity in tropical. There are two kinds of solar cells. One is the commercially available solar cells which use silicon as its semiconductor and the dye- sensitized solar cells (DSSC) which uses dye exclusively from plants. “Most solar cells in use today use silicon as the semiconductor. Though Silicon is abundant (about 25.7%) it is expensive and is in high demand” (CalFinder.com, 2014). “Dye- sensitized solar cell dates back to 1991. Michael Gratzel and Brian O'Regan invented this kind of cell. Dye- sensitized cells are composed of inorganic and organic components” (Bisquert, J., 2004). DSSC are cheaper than silicon solar cells. DSSC is also easy to make that everyone can do it in the comfort of their homes. The main component of the DSSC is the plant pigment called Anthocyanin. Anthocyanin is found mostly in plants that have red to purplish color. Blueberries and raspberries are the common fruits that are known to contain Anthocyanin. “Anthocyanin is known to block off UV radiation. Plants use Anthocyanin to absorb UV radiation to minimize its harmful effects to plants. Anthocyanin is known to be light attenuators. Anthocyanin is also the subject of botanists’ study because of its phytoprotective properties.” (Oregonstate.edu, 2001)

2. Statement of the Problem

The aim of this research is to:

1) Determine which concentration of Anthocyanin used is more effective in terms of output voltage? a) Anthocyanin with 10mL distilled water b) Anthocyanin with 30mL distilled water

2) To compare output voltage of the more effective Dye-sensitized solar cell with the conventional solar cells: a) Standard T-test

3. Significance of the Study

The world calls for a greener source of energy. One way of harvesting greener energy is using solar cells. Solar cells are expensive to make and maintain. “Most solar cells in use today use silicon as the semiconductor. Though Silicon is abundant (25.7% of Earth’s minerals) it is expensive and is in high demand” (CalFinder.com, 2014) On the other hand, making and using dye-sensitized solar cells are way cheaper than silicon solar cells. “Dye-sensitized solar cells attracted a lot of users because of its high efficiency rate 11.1%” (Luk, B., 2010)

4. Scopes and Limitations 1) Only Alugbati extract will be used as dye for the cells. 2) There will be two experimental groups of Dye-sensitized cells; one uses Anthocyanin mixed with 10mL of distilled water and Anthocyanin mixed with 30mL of distilled water. 3) The commercial solar cells used for control group are the small ones (0.2cmx2cm). 4) When comparing the voltage output of the DSSC, standard T-test will be used. 5) When comparing the voltage output of the DSSC and conventional solar cells, paired T-test will be used.

5. Definition of Terms

1) Alugbati- an edible plant. Common in the Philippines. Its reddish/purplish pigment contains anthocyanin. 2) Anthocyanin- the red/blue pigment of certain plants. It helps them to block off harmful effects of UV radiation. 3) UV Radiation- an electromagnetic radiation that has shorter wavelength than visible light. Naturally emitted by the sun’s rays 4) Pigment- the coloring of a plant. Usually green in color and an essential ingredient for photosynthesis. 5) Solar Cell- an electrical device that converts absorbed sunlight into electrical energy.

Chapter II Review of Related Literature
Outline
I. Basella alba (Alugbati) a. Background information II. Anthocyanin a. Definition b. Where they can be found c. Uses III. Dye-sensitized solar cells a. Definition b. Assembly c. Uses d. Efficiency IV. Will the Anthocyanin from Basella alba (Alugbati) work as light-attenuator for dye-sensitized solar cell? V. Comparison of dye-sensitized solar cell which uses Anthocyanin from Basella alba (Alugbati) and commercial solar cells
a. Materials/parts b. Cost & Efficiency

I. Basella alba (Alugbati)
Alugbati, known by many names including malabar, vine spinach, arogbati, dundul and grana is an edible herb that grows usually in warm climates (Martinez, E., 2011). Their stems are purplish or green. The leaves are somewhat fleshy, ovate or heart-shaped, 5 to 12 centimeters long, stalked, tapering to a pointed tip with a cordate base. Spikes are axillary, solitary, 5 to 29 centimeters long. Flowers are pink, about 4 millimeters long. Fruit is fleshy, stalkless, ovoid or nearly spherical, 5 to 6 millimeters long, and purple when mature (Santiago, 2007). The plant is originally from India, and is widely used in the Philippines both as an edible and for its medicinal properties (Stephens, J.M., 1994). Medicinal properties including being used as treatment for headaches, constipation, inflammation and ulcers (Martinez, E., 2011). They are a good source of essential nutrients like calcium, iron, Vitamin A, Vitamin C, Vitamin B and iron. They also contain saponins that act as phytochemicals; fights cancer and other diseases. Their roots are employed as rubefacient – a medicine for external application that produces redness of the skin. The roots are also used as poultice to reduce local swellings. The sap can be applied to acne areas to eliminate irritation. The sap has a softening or soothing effect especially to the skin. Pulped leaves are applied to boils, ulcers and abscesses. Sugared juice of leaves useful for catarrhal afflictions. Leaf-juice, mixed with butter, is soothing and cooling when applied to burns and scalds. Its leaf juice with sugar is effective for inflammation of the nose and throat with increased production of mucus. Also, it is used to treat gonorrhea and balanitis. Its stem and leaf extract can cure habitual headache (Marvin, 2011).

II. Anthocyanin
Anthocyanins are water-soluble vacuolar pigments that may appear red, purple, or blue depending on the pH level. Anthocyanin pigments are responsible for the red, purple, and blue colors of many fruits, vegetables, cereal grains, and flowers (Wrolstad, R.E., 2001). Next to chlorophyll, anthocyanins are the most important group of plant pigments visible to the human eye (Sahelian, R., 2014). They belong to a parent class of molecules called flavonoids synthesized via the phenylpropanoid pathway; they are odorless and nearly flavorless, contributing to taste as a moderately astringent sensation. Anthocyanins occur in all tissues of higher plants, including leaves, stems, roots, flowers, and fruits. Anthoxanthins are clear, white to yellow counterparts of anthocyanins occurring in plants. Anthocyanins are derived from anthocyanidins by adding pendant sugars (Andersen, Ø. M., 2001). In photosynthetic tissues anthocyanins have been shown to act as a "sunscreen", protecting cells from high-light damage by absorbing blue-green and ultraviolet light, thereby protecting the tissues from photoinhibition, or high-light stress. This has been shown to occur in red juvenile leaves, autumn leaves, and broad-leaf evergreen leaves that turn red during the winter. The red coloration of leaves has been proposed to possibly camouflage leaves from herbivores blind to red wavelengths, or signal unpalatability, since anthocyanin synthesis often coincides with synthesis of unpalatable phenolic compounds (Sullivan, J., 1998). In addition to their role as light-attenuators, anthocyanins have a wide range of biological activities including antioxidant, anti-inflammatory, antimicrobial and anti-cancer activities (Sahelian, R., 2014). Earlier studies have shown that berry anthocyanins are beneficial in reducing age-associated oxidative stress, as well as in improving neuronal and cognitive brain function (Sahelian, R., 2014). Anthocyanins are usually found in berries, stems and roots of some. Other than in Basella alba (Alugbati), they have been extracted from Vaccinium myrtillus (Bilberries), Solanum melongena (Aubergine), Rubus (Blackberry), Vaccinium cynoccocus (Blueberry), and many more (Hendry, G.A.F. & Houghton, J.D., 1996).

III. Dye-sensitized solar cells
The Dye-sensitized cell (DSC) is formed by a combination of organic and inorganic components that could be produced at a low cost. The DSC offers the prospect of a cheap and versatile technology for large scale production of solar cells (Bisquert, J., Cahen, D., Hodes, G., Rühle, S., Zaban, A., 2004). It is based on a semiconductor formed between a photo-sensitized anode and an electrolyte, a photoelectrochemical system (European Institute for Energy Research, 2006).
A DSSC functions because of the interactions between the cells anode and cathode, and the nanoparticles of titanium dioxide (TiO2), which are coated with a light-sensitive dye and surrounded by an electrolyte.
The anode (TiO2) is transparent, like glass, so that sunlight can be absorbed by the dye that will convert the photons into electrons. Between the anode and the cathode is a mesh of titanium dioxide nanoparticles that act like a roadway for the electrons coursing through the cell.
An electrolyte (usually iodide) fills the spaces between the TiO2 nanoparticles, and helps transfer electrons from the cathode to the dye molecules (after the dye releases an electron, it needs another to replace the one it lost).
On the other end of the cell is the cathode, typically a film of graphite or platinum. The anode sends electrons from the solar cell through a wire to whatever the cell is powering; then the electrons loop back to the cathode.
Put all these pieces together and you have the basic components of a dye sensitized solar cell (community.nsee.us, N.D.).
For anything to generate electricity, it needs to generate an electric current. In a DSSC, this means that electrons need to be flowing from one end of the cell to the other; in this case, from the cathode to the anode. The electrons travel through the electrolyte and the TiO2 nanoparticles to create an electric current which will power any appliance needing electricity outside the cell. The electrons originate from the dye molecules coating the TiO2 nanoparticles when they are hit by light. Different color dyes can absorb different wavelengths of light, which in turn carry different amounts of energy (community.nsee.us, N.D.).
Dye-sensitized solar cells have many uses and features. They are simple to make using conventional roll-printing techniques, they are semi-flexible and semi-transparent which offers a variety of uses not applicable to glass-based systems, and most of the materials used are low-cost. In practice it has proven difficult to eliminate a number of expensive materials, notably platinum and ruthenium, and the liquid electrolyte presents a serious challenge to making a cell suitable for use in all weather (Tributsch, H., 2004). DSSCs are currently the most efficient third-generation. Other thin-film technologies are typically between 5% and 13%, and traditional low-cost commercial silicon panels operate between 14% and 17%. This makes DSSCs attractive as a replacement for existing technologies in "low density" applications like rooftop solar collectors, where the mechanical robustness and light weight of the glass-less collector is a major advantage. They may not be as attractive for large-scale deployments where higher-cost higher-efficiency cells are more viable, but even small increases in the DSSC conversion efficiency might make them suitable for some of these roles as well (U.S. Department of Energy Office of Basic Energy Sciences, 2005). A disadvantage to the DSSC design though, is the use of the liquid electrolyte, which has temperature stability problems. At low temperatures the electrolyte can freeze, ending power production and potentially leading to physical damage. Higher temperatures cause the liquid to expand, making sealing the panels a serious problem. Although the dye is highly efficient at converting absorbed photons into free electrons in the TiO2, only photons absorbed by the dye ultimately produce current. The rate of photon absorption depends upon the absorption spectrum of the sensitized TiO2 layer and upon the solar flux spectrum. The overlap between these two spectra determines the maximum possible photocurrent. Typically used dye molecules generally have poorer absorption in the red part of the spectrum compared to silicon, which means that fewer of the photons in sunlight are usable for current generation. These factors limit the current generated by a DSSC, for comparison, a traditional silicon-based solar cell offers about 35 mA/cm2, whereas current DSSCs offer about 20 mA/cm2. Overall peak power conversion efficiency for current DSSCs is about 11% (Gao, F. et al., 2008). Current record for prototypes lies at 15%. IV. Will the Anthocyanin from Basella alba (Alugbati) work as light-attenuator for dye-sensitized solar cell?
In previous researches, it has been proven that the Basella alba plant contains anthocyanin, which gives the plant’s stem and ‘fruits’ its reddish hue, and it commonly used as dye.
In photosynthetic tissues, anthocyanins have been shown to act as a "sunscreen", protecting cells from high-light damage by absorbing blue-green and ultraviolet light, thereby protecting the tissues from photoinhibition, or high-light stress (Karageorgou P., Manetas Y., 2006). They also have the ability to convert light energy into electrical energy (Cherepy, N.J., Smestad, G.P., Grätzel, M., Zhang, Z. 1997).
Summing up those two, we can assume that the extracted anthocyanin from the Basella alba plant can be used for dye-sensitized solar cells. V. Comparison of this dye-sensitized solar cell which uses Anthocyanin from Basella alba (Alugbati), and commercial solar cells
A solar cell is an electronic device which directly converts sunlight into electricity. Light shining on the solar cell produces both a current and a voltage to generate electric power. This process requires a material in which the absorption of light raises an electron to a higher energy state and the movement of this higher energy electron from the solar cell into an external circuit. The electron dissipates its energy in the external circuit and returns to the solar cell.
The two common types of commercial solar cells are thin film and crystalline silicone. Thin film solar cells usually consist of: Glass, Low resistivity Oxide coating, High resistivity Oxide coating, n-doped CdS window, p-doped CdTe absorber, Au contact. Crystalline silicon consists of: cover glass, transparent adhesive, antireflection coating, front contact, n-type semiconductor, p-type semiconductor, back contact, substrate (1portal.net, N.D.).
Compared to thin film and crystalline silicon solar cells, dye-sensitized solar cells require lesser parts. DSSCs only need glass, Transparent conductive oxide (TCO), Titanium Dioxide blocking layer, Titanium Dioxide, Dye (the Basella alba Anthocyanin for this case), Hole conductor and Electrode (Grätzel, M., 2013). And because DSSCs require lesser parts, they also cost less. The only parts where you’ll need to spend money on is the specialized glass (usually Indium tin oxide-coated glass), TiO2, and the chemicals for the redox reaction.
The cost of commercial solar cells depend on manufacturing, where any costs are proportional to the panel area or land area involved, and consumer installation costs. Installation costs have reduced only slowly, because of its reliance on human labor. Concentrated solar power offers greater economies of scale, given its much larger size (Gupta, N., Alapatt, G.F., Podila, R., Singh, R., & Poole, K. F., 2009).
In comparing the efficiency of commercial solar cells and dye-sensitized solar cells, commercial solar cells have a higher percentage of efficiency (based on previous studies). In September 2013, a solar cell achieved a new laboratory record with 44.7 percent efficiency, as demonstrated by the German Fraunhofer Institute for Solar Energy Systems. In 2014, three companies broke the record of 25.6% for a silicon solar cell. Meanwhile, dye-sensitized solar cells’ overall peak power conversion efficiency is about 11% (Gao, F. et al., 2008). Current record for prototypes lies at 15%.

CHAPTER III
METHODOLOGY

A. Preparation of Materials The main material in the experiment is the Anthocyanin from Basella alba (Alugbati). The Anthocyanin is the red-pigment that found in plants or fruits that are very abundant and are rich in color red and violet.
Titanium Dioxide was used as another component to easily absorb ultraviolet rays. Additionally, it is a semi-conductor, which means that there are actually free electrons in the current carriers (Marshall, 1942).
The redox shuttle that is composed of iodine crystals, potassium iodine and ethylene glycol would be used to generate electricity from the dye or the anthocyanin. The glass used in the experiment is Indium Tin Oxide glass. It is a specialized glass that has a semi conductive side. Other apparatuses and materials used were water, beaker, forceps, scalpel, petri dish, stirring rod, acetic acid 6M, dishwashing detergent, vial, tape, and multi-tester. Figure 3.1 Materials
B. Extraction of Anthocyanin The system used in the experiment was where the anthocyanin removed manually by scraping the ‘skin’ or layer of the red to purplish-pigment from the stems. Petri dishes were used as the container of the collected anthocyanin.

Fig 3.2 Alugbati (Basella Alba) Fig 3.3 Scraping anthocyanin from the stems Fig 3.4 Anthocyanin collected The stems of the Alugbati were washed before the extraction. The leaves were cut to obtain the main stem. With the use of scalpel, the layer of the red-pigment of the stem was removed on the petri dish. There 2 concentrations of anthocyanin used. 50 grams of stem mixed with 10mL of water and 50 grams of stem mixed with 30mL of water. The strainer is used to filter off the pulps and other bits that are scraped along.
C. Creating the Solar Cell 2 grams of TiO2 (Titanium Dioxide) is mixed with 2.25 mL of Acetic Acid 6M in a vial. A drop of dishwashing detergent was added on each mixture in able for the pastes to stick on the glass. With the use of glass rod the mixture was mixed until it turned into paste-like substance The resistance on each side of the glass was identified with the use of the multi-tester. The conductive side should have the lower resistance between the two sides. At least 5mm on each side of Indium Tin Oxide glass excluding the bottom part was taped and the paste was applied onto the exposed area of Indium Tin Oxide. The paste should be smeared evenly and should not be too viscous or dry. When the paste is dry, remove the tape and put the glass on a hot plate. The TiO2 will eventually turn yellowish and back to white to indicate that the cell is ready. The detergent and vinegar will burn and be combined with the TiO2 to stick to the glass. After a span of time, add drops of anthocyanin into the pastes. Rinse off the other unnecessary components with water and alcohol. A redox shuttle solution is needed to help the anthocyanin capture more sunlight to turn into electrical energy. The Redox shuttle is made by mixing 127 mg of iodine crystal, 830 mg of potassium iodide and 10 mL of ethylene glycol. Another slide was prepared and the conductive side was exposed on a candle flame until it creates soot that will used to catalyze the redox shuttle. Wipe the glass with the soot into the size like the previous slide before adding drops of redox shuttle solution. Combine the two conductive sides with each other. Use a cloth or tissue to absorb the excess redox shuttle. Fasten the two slides with the use of binder clips.

Figure 3.5 TiO2 paste Figure 3.6 ITO on hotplate Figure 3.7 TiO2 dye-sensitized solar cells (not yet dyed)
Table 3.1 Number of cells made using TiO2 Anthocyanin mixed with 10 mL of water | Anthocyanin mixed with 30 mL of water | Cell 1 | Cell 1 | Cell 2 | Cell 2 | Cell 3 | Cell 3 | Cell 4 | Cell 4 | Cell 5 | Cell 5 | Cell 6 | Cell 6 | Cell 7 | Cell 7 | Cell 8 | Cell 8 | Cell 9 | Cell 9 | Cell 10 | Cell 10 |

D. Testing the Cell Alligator clips were placed on the exposed ends of the glass (the 5mm). All DSSC is in open circuit. Multi-tester was used to test voltage of the cell. Voltage output of the TiO2 is recorded. Paired T-test was used to compare the voltage output of the cell subjects of different Anthocyanin concentrations.

Table 3.2 Comparing Voltage output of dye-sensitized cells Anthocyanin mixed with 10 mL of water | Anthocyanin mixed with 30 mL of water | Cell 1 | Cell 1 | Cell 2 | Cell 2 | Cell 3 | Cell 3 | Cell 4 | Cell 4 | Cell 5 | Cell 5 | Cell 6 | Cell 6 | Cell 7 | Cell 7 | Cell 8 | Cell 8 | Cell 9 | Cell 9 | Cell 10 | Cell 10 |

The best dye-sensitized solar cell was then compared to commercially available solar cells. Standard T-test was then used to compare the voltage output of dye- sensitized cell and the conventional solar cell.

Table 3.3 Comparing Voltage output of dye-sensitized cell and conventional solar cell Anthocyanin mixed with 10 mL of water | Anthocyanin mixed with 30 mL of water | Cell 1 | Cell 1 | Cell 2 | Cell 2 | Cell 3 | Cell 3 | Cell 4 | Cell 4 | Cell 5 | Cell 5 | Cell 6 | Cell 6 | Cell 7 | Cell 7 | Cell 8 | Cell 8 | Cell 9 | Cell 9 | Cell 10 | Cell 10 |

CHAPTER IV
DATA AND DISCUSSION

I. Voltage output of experimental dye-sensitized solar cells

Figure 4.1 with 10mL H2O Figure 4.2 with 30mL H2O After the dye-sensitized solar cell was made, it was exposed to sunlight. After that, the voltage output of different Anthocyanin concentrations of dye-sensitized solar cells was measured using a multi-tester and the data was recorded.

Table 4.1 Voltage Output

Cell # | Anthocyanin mixed with 10 mL of water | Anthocyanin mixed with 30 mL of water | Cell 1 | 0.165 V | 0.145 V | Cell 2 | 0.157 V | 0.147 V | Cell 3 | 0.154 V | 0.148 V | Cell 4 | 0.156 V | 0.147 V | Cell 5 | 0.151 V | 0.151 V | Cell 6 | 0.155 V | 0.149 V | Cell 7 | 0.161 V | 0.154 V | Cell 8 | 0.159 V | 0.144 V | Cell 9 | 0.161 V | 0.151 V | Cell 10 | 0.158 V | 0.148 V |

Using Paired T-test, our computation showed that the Voltage output of DSSC that uses Anthocyanin mixed with 10mL of water has significant difference over the DSSC that used Anthocyanin mixed with 30mL of water. Using the result of the Paired T-test, the best DSSCs which are the ones with Anthocyanin mixed with 10mL of water will then be compared to the conventional solar cells.

II. Voltage output of experimental best dye-sensitized solar cells vs. commercially available solar cells

Figure 4.1 Anthocyanin DSSC Figure 4.2 Commercially available solar cells After the dye-sensitized solar cells’ voltage output was measured, the best data was chosen to compare it to commercially available solar cells. The cells were exposed to sunlight. After that, the voltage output of the dye-sensitized solar cells and the commercially available solar cell was measured using a multi-tester and the data was recorded.

Table 4.2 Voltage Output

Cell # | Dye-sensitized solar cells | Conventional solar cell | Cell 1 | 0.165 V | 0.473 V | Cell 2 | 0.157 V | 0.467 V | Cell 3 | 0.154 V | 0.470 V | Cell 4 | 0.156 V | 0.478 V | Cell 5 | 0.151 V | 0.469 V | Cell 6 | 0.155 V | 0.475 V | Cell 7 | 0.161 V | 0.478 V | Cell 8 | 0.159 V | 0.471 V | Cell 9 | 0.161 V | 0.466 V | Cell 10 | 0.158 V | 0.472 V |

Using Standard T-test, our computation showed that the Voltage output of conventional solar cells have significant difference over the DSSC that used Anthocyanin mixed with 10mL of water. With these accumulated data, we can infer that the dye-sensitized solar cells can generate energy, but a smaller value compared to conventional solar cells. The factors that could have affected our data might include: the concentration of the Anthocyanin extracted- the amount of H2O mixed with the Anthocyanin extract. Since the Anthocyanin is the one that absorbs sunlight, diluted Anthocyanin may have an effect to the voltage output the DSSC generated. Using pure Anthocyanin could improve the results. The quality of the glass used (which in our case is glass from touchscreen phones, coated with Indium Tin Oxide) could also have affected our data. The screen of the touch screen phones are delicate and easy to break. The redox catalyst is basically made by mixing Iodine crystals, Potassium Iodide, and Ethylene Glycol. Unfortunately Iodine corrodes with metallic current collectors. This is the reason why DSSCs have a short lifespan. It could also have affected our data for voltage output.

CHAPTER V

GENERALIZATION, CONCLUSION, RECOMMENDATION

GENERALIZATION Though the Voltage output that DSSCs can produce is relatively small compared to the voltage output of conventional solar cells, DSSCs have a potential to replace conventional solar cells in the future. DSSCs are crude solar cells and have a shorter lifespan than conventional solar cells. But when fully developed it might even be one the leading sources of energy as it is cheap to make and easy to do.
CONCLUSION
DSSCs can generate voltage of 0.140V – 0.170 V which is a promising start. It can be developed further in the future. At present, DSSCs cannot replace conventional solar cells for large scale uses, but they can be useful in regular households. We hope that DSSCs can achieve the efficiency and life span of conventional solar cells by improving the methods and the materials used in making DSSCs in the future. In conclusion, DSSCs can serve as replacements for conventional solar cells in small scale uses for the meantime. They are cheap and can generate just enough amount of energy for small batteries and such.
RECOMMENDATIONS
We recommend for the next experimenters not to use the Indium Tin Oxide glass obtained from the screens of touchscreen gadgets. Indium Tin Oxide glass obtained from these gadgets is thin and can easily break when exposed to extreme heat. Carbon soot can also be replaced with a better redox catalyst. Commercial solar cells often use Platinum that is very expensive. Finding a better redox catalyst can improve the performance of DSSC. The Redox shuttle is Iodine based. This has a disadvantage because Iodine corrodes with metallic current collectors. Finding an alternative redox shuttle could improve the output voltage of the DSSCs. Anthocyanin from different plants can effectively be an alternative for Anthocyanin from Alugbati. Pure Anthocyanin which is free from sugar and other components from plants can also be extracted using more sophisticated methods rather than just scraping the skin or getting the juice of the plant/fruit.

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