Anthocyanin Solar Cell Degradation Study

ISEF Category: Energy: Sustainable Materials and Design

Subcategory: Solar Process, Materials, and Design  ·  Difficulty: Intermediate  ·  Setup: School Lab  ·  Time: 1 to 2 Months

The Hook

A berry pigment can act like a tiny light catcher inside a solar cell. That means the same color that stains your hands can help move electrons. UV light can also break that pigment down over time. You can test how fast that happens and what that means for solar cell output.

What Is It?

Dye-sensitized solar cells, or DSSCs, are solar cells that use a dye to absorb light. In this project, the dye comes from anthocyanins, the pigments that give berries and red cabbage their red, purple, and blue colors. Think of the dye as a middleman. It grabs light energy, then helps start the flow of electrons that make electricity.

Your main question is not just whether the cell works. You want to know how fast it loses performance when UV light hits the dye for too long. That loss is called degradation. You can think of it like sunscreen fading in the sun, except here the fading changes how well the solar cell can do its job.

A phone-based lux meter helps you track light levels in a simple way. Lux measures how bright light looks to the human eye, so it is not the same as solar power. Still, it can help you compare samples under the same lighting setup and follow relative changes over time. That makes it useful for a student project when you pair it with careful controls and repeat measurements.

Why This Is a Good Topic

This is a strong science fair topic because you can measure a real performance change and connect it to a real energy problem. Anthocyanin dyes are cheap, plant-based, and easy to source, so you can test more than one extract without a major budget. You can study a clear variable, UV exposure, and turn the results into degradation curves, which gives you real data analysis practice.

Research Questions

• How does UV exposure time affect the light output of anthocyanin-based dye-sensitized solar cells?
• What is the effect of berry source on the degradation rate of anthocyanin solar cells?
• Does red cabbage extract degrade faster or slower than berry extract under the same UV conditions?
• To what extent does dye concentration change the starting output and the rate of decline in DSSC performance?
• Which storage condition, dark, room light, or UV-exposed, best preserves anthocyanin dye performance over time?
• How does the pH of the extract affect the stability of the dye and the solar cell signal?

Basic Materials

• Red cabbage or mixed berries for dye extraction.
• Filter paper or coffee filters for cleaning extracts.
• Clear glass or plastic cups for sample preparation.
• Transparent containers or small sealed jars for light exposure trials.
• Smartphone with a lux meter app.
• Simple multimeter for checking cell output.
• Binder clips or tape for holding samples in the same position.
• White paper or a matte background for consistent phone readings.
• UV flashlight or access to a controlled UV source.
• Notepad or spreadsheet for recording measurements.

Advanced Materials

• Conductive glass slides or ready-made DSSC substrates.
• Titanium dioxide paste or coated photoanode substrates.
• Counter electrode materials such as graphite or platinum-coated slides.
• Electrolyte appropriate for DSSC assembly.
• UV-Vis spectrophotometer for absorbance tracking.
• Potentiostat or source meter for current-voltage curves.
• Solar simulator or calibrated light source.
• pH meter for extract characterization.
• Centrifuge and micropipettes for cleaner extract preparation.
• Sealed test chamber for controlled aging experiments.

Software & Tools

• Google Sheets: Organizes repeated measurements, calculates averages, and graphs degradation trends.
• ImageJ: Measures color change in extracts or device photos when you need a simple visual proxy.
• Python: Fits decay curves and compares degradation models across dye sources.
• Tracker: Helps if you record any time-based changes in a simple video setup.
• Desmos: Lets you sketch quick trend lines and compare candidate equations before deeper analysis.

Experiment Steps

1. Define the exact performance metric you will track, such as lux output, voltage, current, or absorbance change.
2. Choose one dye source first, then decide whether you are comparing extract type, pH, or UV exposure level.
3. Set up a repeatable measurement station so every reading happens under the same geometry and light conditions.
4. Build a baseline curve before UV exposure so you know the starting behavior of each sample.
5. Plan a degradation timeline that includes matched controls kept away from UV light.
6. Decide how you will fit the data, compare slopes, and test whether the differences are larger than normal variation.

Common Pitfalls

• Mixing lux readings with true solar output, which can make the performance claim too broad.
• Using room light or sunlit windows during measurement, which changes the signal from one session to the next.
• Comparing extracts with different thicknesses or concentrations, which hides whether the dye or the setup caused the change.
• Letting the phone angle or distance shift between readings, which breaks the calibration.
• Treating pigment fading as the same thing as solar cell failure, which can blur whether the dye, the electrode, or the contact is the weak point.

What Makes This Competitive

A stronger project goes beyond a simple before-and-after test. You can compare multiple plant dyes, fit the decline to a decay model, and test whether one extract holds up better under the same UV dose. You can also separate dye breakdown from device loss by tracking both color change and electrical output. That kind of layered analysis shows real control over the experiment.

Project Variations

• Compare anthocyanin extracts from blueberries, blackberries, and red cabbage to see which one degrades slowest under UV light.
• Test how acidified versus neutral extracts change the starting output and stability of the dye-sensitized solar cell.
• Track both color loss and electrical output in the same samples to see whether visual fading matches device degradation.

Learn More

• NASA Solar Energy Basics: Search NASA for clear background on how solar cells convert light into electricity.
• PubMed: Search for review articles on anthocyanins, plant pigments, and dye stability under light exposure.
• NOAA UV Index resources: Use NOAA to understand UV intensity, exposure, and how sunlight varies by location and season.
• USGS Water and Science School: Search USGS background pages for absorbance, color, and basic measurement ideas that help with solution studies.
• MIT OpenCourseWare: Search for materials science or solar energy courses that explain solar cell design and measurement.