today i want to share how to make a solar cell at home easily and it is fun to make.but firstly i want to tell you dont expect to light your house with these solar cells because it produces small voltage and may need acres of them to power the house!but yet it is easy and need ordinary stuff .but little caution is needed to handle and make the cell.it is great for science classes and projects
visit my profile:https://www.instructables.com/member/argha+halder/ to see some more of such interesting projects.
Step 1: Things Needed:
the things you will need:
1)gas or electric stove
2)copper plate or flashers -2
3)a transparent plastic or glass container
the tools you will need:
1)voltmetre(just for testing)
Step 2: Making the Semi Conductor Layer Part-1
every solar cell has a semi conductor plate and our cell contains one which is cuprous oxide that is made by burning or heating copper,why it is necessary is given in the step "how does it work".so first take one of the two copper plates and hold it with a pliers.now turn on the stove and put the copper on the fire.the colour of the copper would start to become mixed like orange red and many other colour in one copper.heat it in that state for 20 minutes.
be extremely careful not to burn your hand and dont touch or dip the copper in water while its hot.
Step 3: Making the Semi Conductor Part-2
now take the heated copper and put aside on a dry place to cool.after some time you will see some black flakes is starting to pop and break and flying away.the skin will start to appear.now when it fully cools down the flakes will fall from the full copper plate and the copper will take reddish brown colour.now using hand or sand paper remove the flakes from the copper surface.
now take the transparent plastic container and pour some water in it.now take some salt and keep dissolving until any more salt does not get dissolved.
Step 5: Making the Connections Well
now take the heated copper and solder a wire to it.now take a normal copper plate and add an wire to it.
Step 6: Setting Everything Up!
now lets set everything.first take the two copper plates and place on the two inner sides of the tranparent plastic container containing salt water.make sure the two copper plates does not touch each other.its ready!the cuprous oxide end is the negative end and the copper is the positive end
Step 7: Lets Test It!!
now first add the wires of the solar cell we made to a voltmetre.now in the dark see that it is producing a small volt around 0.02-4.now bring the cell in the sun and see the metre jump to almost 0.40 volts!i know it is not very much.but i can't think of anybody who wont be happy to see it work.now dont expect it to run your house.
Step 8: How Does It Work?
Cuprous oxide is a type of material called a semiconductor. A semiconductor is in between a conductor, where electricity can flow freely, and an insulator, where electrons are bound tightly to their atoms and do not flow freely.
In a semiconductor, there is a gap, called a bandgap between the electrons that are bound tightly to the atom, and the electrons that are farther from the atom, which can move freely and conduct electricity.
Electrons cannot stay inside the bandgap. An electron cannot gain just a little bit of energy and move away from the atom's nucleus into the bandgap. An electron must gain enough energy to move farther away from the nucleus, outside of the bandgap.
Similarly, an electron outside the bandgap cannot lose a little bit of energy and fall just a little bit closer to the nucleus. It must lose enough energy to fall past the bandgap into the area where electrons are allowed.
When sunlight hits the electrons in the cuprous oxide, some of the electrons gain enough energy from the sunlight to jump past the bandgap and become free to conduct electricity.
The free electrons move into the saltwater, then into the clean copper plate, into the wire, through the meter, and back to the cuprous oxide plate.
As the electrons move through the meter, they perform the work needed to move the needle. When a shadow falls on the solar cell, fewer electrons move through the meter, and the needle dips back down.
Step 9: How to Make It Stronger
you can add two or three cells in parrallel and charge a battery of 1.5 volts with it.or you can make a joule thief to increase the volt.here is a link to make a joule thief instructions:https://www.instructables.com/id/make-a-joule-thief-easily/.or you may increase the size of copper plates and use a magnifiying glass to increase the brightness of light and centerise the light alling on a large place.you may put covering or sealing to not let the salt water dry.the ways are limitless.
Step 10: Troubleshooting
if your cell does not work then be sure you properly made the cuprous oxide or not.see whether you have not kept the copper place touching each other.make sure the plates are not touching each other.make sure you dont use cuprous oxide even instead of the bare copper plate.remember one plate should be copper and the other should cuprous oxide.i dont know or faced any more problems.
i am argha halder living in naogaon bangladesh.i read in class 7.i dont know english much as it is not my mother tongue language.and so if any mistake help me find it.give some more ideas.feel free to ask questions.i will try to answer them as much as possible for me.oh! i am soon shifting to usa.so maybe this will be my last instructable in 1 or 2 months.till then bye!have a nice day