The students will learn to fabricate an artificial photosynthetic device using nanotechnology and plant pigments to capture sun's energy and convert it to electricity. Each Activity prepares students for the Design Project, in which they are challenged to create the most efficient dye-sensitized solar cell, using vegetable and/or fruit dyes, that is capable of powering an electronic device.
The new math extension deals with a variety of math topics, linked by subject matter or a key word or concept to the material presented in the activities and design project. These include density and specific gravity of materials, growth curves (a simple model and two more complex ones), waves and electromagnetic spectrum data (represented by NASA-type problems) and lastly, electric current and resistance problems.
When advanced or particularly difficult problems are included, they have been marked with an asterisk (*) in the Table of Contents.
Activity 1: Investigating the Photosynthesis of Plant Disks
Students study how various wavelengths of light affect the rate of photosynthesis in a plant leaf. They measure the rise in plant leaf disks immersed in bicarbonate solution as direct evidence of the light-dependent reactions accompanied by the evolution of oxygen gas.
Activity 2: Separating Leaf Pigments Using Paper Chromatography
Students use paper chromatography to separate the mixture of pigments in plant leaves and learn about the different portions of the solar spectrum they absorb. They also examine the chemical structures of the pigments and make predictions about the rate of separation for the given solvent.
Activity 3: Measuring a Solar Cell’s Performance
Students determines the current and voltage characteristics of a commercial silicon-based solar cell. They then use the solar cell to explore the idea of matching internal resistance to achieve the best power transfer from the solar cell to a light bulb.
Activity 4: Making a Dye-Sensitized Solar Cell (DSSC)
Students use nanoparticles and vegetable or fruit pigments to fabricate artificial photosynthetic solar cells for capturing light energy and convert it to electricity. They also measure and compare the output current and voltage characteristics of their dye-sensitized solar cells made with two different dyes.
Pre-Design Activity: Interactive Solar Cell Design Game
As a review of DSSC working concepts and precursor to the design project, students use the interactive learning game to make practical design decisions regarding cost, types of dye and their absorption spectra, thickness of coating, in order to create the best possible solar cell within a limited funding budget.
Design Project: Maximizing Solar Energy Absorption in DSSC
Students are challenged to construct a set of prototype DSSCs that maximizes absorption of light energy. To meet specific performance criteria, students make a number of choices regarding the design of their prototypes. Students test and evaluate their prototypes and then redesign the prototypes to make them more effective. Finally, students team up to put their best DSSCs together to demonstrate their capability to power an electronic device.
Connecting to Your Curriculum
Materials World Modules are simple to organize and inexpensive to run. They are designed to be easily incorporated into any middle school science or high school science lab or lecture course. The chart below lists the subjects covered in the Activities and Design Projects sections of this module.
Geology and Earth Science
Physics & Physical Science
Biology and Life Science
Zinc Oxide Nanowires for Organic Bulk Heterojunction Photovoltaic Cells (pop-up window)
A Research poster by Departments of Materials Science and Engineeirng, Department of Chemistry at Norhtwestern University. Organic solar cells have the same theoretical maximum efficiency as pn-junction solar cells but their production requires less energy than traditional pn-junction cells...