Building a solar cell- electrochemistry- Sources of Energy
Activity Author
Lubna Naseem
Duration
weekend project
Objective: Key Core Life Skill to be developed
a:2:{i:0;s:17:"Critical thinking";i:1;s:15:"Problem Solving";}
Objective: Key Learning Domains to be developed
a:2:{i:0;s:10:"Understand";i:1;s:11:"Application";}
Implemented this in classroom
Objectives to be achieved
Introduction to semiconductors and how do they work
Materials other than silicon can be used to display photoelectric effect- like cuprous oxide
create their own solar battery using cuprous oxide
Underlying Concept behind this activity
Students need to understand that before silicon was discovered as a semiconductor Cuprous oxide is one of the first materials known to display the photoelectric effect, in which light causes electricity to flow in a material. This will create curiosity on what is the concept of photoelectric effect and how it works.
Resources required for conducting the activity
A sheet of copper Size half a square foot.
Two alligator clip leads.
A sensitive micro-ammeter that can read currents between 10 and 50 microamperes.
Electric stove (Just to save gas)
A large clear plastic bottle off of which you can cut the top
Table salt.
Tap water.
Sand paper or a wire brush on an electric drill.
Sheet metal shears for cutting the copper sheet
Class Activity Details
Step1 :Cut a piece of the copper sheeting that is about the size of the burner on the stove. Wash your hands so they don’t have any grease or oil on them. Then wa
sh the copper sheet with soap or cleanser to get any oil or grease off of it. Use the sandpaper
or wire brush to thoroughly clean the copper sheeting, so that any sulphide or other light corrosion is removed.
Step 2: Place the cleaned and dried copper sheet on the burner and turn the burner to its highest setting.
Step 3: Cut another sheet of copper about the same size as the first one. Bend both pieces gently, so they will fit into the plastic bottle or jar without touching one another.
Note: The cuprous oxide coating that was facing up on the burner is usually the best side to face outwards in the jar, because it has the smoothest, cleanest surface.
Step4: Attach the two alligator clip leads as shown in the picture, one to the new copper plate, and one to the cuprous oxide coated plate. Connect the lead from the clean copper plate to the positive terminal of the meter. Connect the lead from the cuprous oxide plate to the negative terminal of the meter.
Step 5: Now mix a couple tablespoons of salt into some hot tap water. Stir the saltwater until all the salt is dissolved. Then carefully pour the saltwater into the jar, being careful not to get the clip leads wet. (The saltwater should not completely cover the plates — you should leave about an inch of plate above the water, so you can move the solar cell around without getting the clip leads wet.)
Notice that the meter is reading about 6 microamps of current.
The solar cell is a battery, even in the dark, and will usually show a few microamps of current.
Practice worksheets
This activity has been inspired by:
http://sci-toys.com/scitoys/scitoys/echem/echem2.html
You can ask students to make their observations on how long did the battery work -
1. Under bright sun
2. Under shadow
3. Without Sun
Uploaded File
Download File
Brainstorming questions asked in class
Questions to be asked:
How is copper sheet when converted into cuprous oxide end up working as a solar cell? Explain the process that's taking place when sun rays heat the sheet.
Evaluation parameters to assess the understanding of the students
Clearly explained, Knowledgeable, Methodical, Precise, Well crafted/ articulated, Informative
Impromptu changes made if any during activity, reasons
Any suggestions for other teachers while implementing this activity in classroom.
