Solar Cell
How To Build a “Thin-Film” Solar Cell
Author: Gallen Ho
Learning how to build a “Thin-Film” solar cell is very interesting educational project and it helps you get to grips with the photoelectric effect.
What You Need:
• Copper sheeting
• Clear Plexiglas/Perspex/acrylic sheeting
• Some thin wood strip
• Copper wire
• Duct tape
Tools:
• Metal guillotine (optional)
• Bandsaw (optional)
• Tin snips
• Electric ring hob
First of all, cut a square of the copper sheeting so that it is about 6-8 in. square in size. It is much easier to do this with a metal guillotine; however, if you haven’t got access to this sort of equipment, tin snips will work just fine.
When you have done this, wash your hands thoroughly and dry them. You need to remove any grease or oil from your hands that could cause problems with the next step of the process. Remove any grease or detritus from the copper sheeting. Next, take a piece of emery cloth, and thoroughly sand down the piece of copper on both sides to remove the top layer of oxidized copper.
This will leave you with nice bright shiny red copper underneath.
You now need to heat treat the copper, in order to form an oxide coating on top. It may sound counterintuitive that we have just removed all the oxide and now we are going to put oxide back on, but the oxide coating we will be applying will be a film of “cuprous oxide.”
You will need an electric hob to do this. If you have any “heat proof goves” and metal tongs, this might be the time to get them in order to handle the metal while hot.
You need to turn the burner to the highest setting, with the sheet of copper just placed on top. Observe the changes to the copper carefully, they are very interesting.
As you heat the copper, it takes on a lovely vivid patina of different colors.
If you have access to nitric acid, you can use this as a superior method for removing the upper cupric oxide layer.
You will see a black crusty oxide form on top of the copper plate. If you leave the plate to cool slowly, the crusty layer should become fairly fragile and separate easily from the underlying copper. When you have allowed the plate to cool thoroughly, give the plate a firm bang edge-on to a hard surface. Some of the oxide will pop off. Rub the oxide gently with your fingers under a tap, and you will find most of the black layer of oxide comes off easily. If any bits are stubborn, do not under any circumstances scour them, as we do not want to damage the fragile surface.
Under this black layer of oxide, you will find another layer of reddish orange rust color. This is the layer which is “photosensitive” and will make our thin-film solar cell work.
Make a spacer now from some thin strips of wood. I used duct tape to join my pieces of wood together – Do not use metal fixings as they could react electrolytically with the other components of the cell.
We are now going to make another electrode. It has to have the property that it does not touch the other piece of the solar cell, and allows light to hit the surface. We are going to use salt water as our other electrode, making contact with the whole surface of the thin film cell, yet conducting electricity. We are then going to immerse another copper wire to make the connection. You could equally use another piece of copper plate around the outside of the thin-film cell, but not touching our oxidized copper.
In a commercial thin-film cell, tin oxide is commonly used as the other electrode, as it is clear and yet conducts electricity.
Now take a piece of Perspex to act as a cover plate, and stick a strip of duct tape on either side.
We are going to stick our other electrode wire to this piece of Perspex.
Remember to use thickish wire for clarity, with few actual zigzags so that you can clearly see what is going on. To optimize the performance of your solar cell, you want to make the conductor large. To this end, you are better using lots of thinner gauge wire in a much finer zigzag pattern-this will still allow the light to get through, but at the same time gives a large conductor area.
You can experiment with different types of wire And copper – The trick is to try and maximize the surface area of the copper, while trying to block as little light as possible from reaching the solar cell.
Fold the duct tape over and stick the wire to the plate.
We are now going to combine the electrode plate with the space. Again, duct tape makes this a nice easy job.
Next, we are going to take the copper plate, and stick duct tape to one side, with the sticky side of the tape facing the same direction as the layer of red copper oxide.
Combine the plate and the front module to make the finished solar cell.
Now, take a little salt water, and fill the void between the Perspex front section and the copper plate. Seal the module with duct tape all round to prevent leakage.
Finally, connect your module to a multimeter, find a bright light source, and explore some of the electrical properties of your solar cell.
Article Source: http://www.articlesbase.com/diy-articles/how-to-build-a-thinfilm-solar-cell-1130557.html
About the Author
Explore the highly recommended Earth For Energy site that provides you with wealth of information on learning how to build solar panels, solar hot water heaters and many other informative tips on generating free energy. Learn how to build a solar panel today; Master the true knowledge of generating energy.
November 30, -0001
12:00 am #comment-1
good question…
the next big advance could be an energy source that renews itself…
i want to see a laser beam onto a solar panel charging a battery that fuels the laser and also my car, and one for my house too would be great.
this is probably not going to happen for many reasons and there is probably another way to achieve this goal of a self charging battery.
but this is a good example of how we could make a good energy source.
November 30, -0001
12:00 am #comment-2
varati
The fallowing is cut directly out of a DIY guide I wrote on the subject, for more the complete guide visit
http://www.agua-luna.com/guides.html
“STEP 1. SOLAR PANELS: or PV panels are the key to a hybrid system., converting the sun’s beams into electricity that we can use in the home. They come in many different sizes, shapes, power ranges and costs. We will focus on a 12v 50watt (4amp) panel, measuring appx 4 sq. ft. with a price range from $300-$500.
http://www.mrsolar.com ($340)
http://www.agua-luna.com ($299)”
“Retrieve a typical winter electric bill. You won’t need a summer bill, because by building a system that runs in winter, it’ll be proven for summer use where days are longer. Divide the total KWH (Kilowatt Hours) on the bill by 30 (giving you your Kilowatt Hour per day, or KWH/d consumption amount), now divide that by 10 (or the total average winter day hours in your area)(giving you KWH/h), now multiple that by 1000 (converting KWH/h to WH/h or watts).”
“Now that we know how many watts your systems requires, we need to know how many panels to use, along with an adequate- sized controller. For simplicity reasons, let’s use a typical 50w solar panel. We will divide your final “system requirement” results from above by 50 to tell us how many panels you’ll need (hourly winter consumption watts / 50).”
“NOTE: Size (watts and feet) of panels is a personal choice and isn’t determined by any system requirements.
Mount panel/s flat (0 degree) facing south (if located in the north hemisphere). With a multimeter, measure the incoming amps (via pos cable to battery), slowly raise the top edge until the amps peak on your meter. Secure.”
Hope this helped, feel free to contact me personally if you have any questions, I’m willing to walk you step by step threw the conversion process if you’re interested. I also offer on line and on-site workshops.
Dan Martin
Retired Boeing Engineer now living 100% Off-the-Grid with my family, using Alternative Energy & loving every minute.
for more info visit agua-luna or email me at agualuna@lycos.com
November 30, -0001
12:00 am #comment-3
Solar cells are made from silicon metal. Refining pure metals requires a lot of energy and this comes from burning fossil fuels. Smelting metals is often an environmentally dirty process too.
November 30, -0001
12:00 am #comment-4
There is more than one type of solar technology and it is getting more efficient all the time. All I know for sure is my PV system generates more energy than I was quoted and I will break even in about 6 years so I’ll have about 18 years of free energy which will save me well over $50K. That’s efficient enough for me.
I came accross a new, proven and tested home made wind power system and solar power system which eliminates our electricity bills. It was written by a Renewable energy enthusiasts Michael Harvey the diy called Earth4energy. You can get your copy to save energy and help environment while eliminating your power bills. Get it from here: http://homemadeenergyreviews.blogspot.com/
November 30, -0001
12:00 am #comment-5
The correct rate is 11kWhr per day. 11kw would be a horrendous amount of power.(maybe Al Gore uses it at this rate)
I will calc it at your rate for problem sake. (this is not real life by the way, there are lots more variables, length of day, etc)
200W/m^2 * 15% = 30w/meter
11kw / 30w/meter = 366m^2
On a side note I think mastering physics is a crappy program, made for lazy physics teacher that dont ever care about application of knowledge.
January 24, 2007
7:00 am #comment-6
………::::::::::Solar cell:::::::::………..?
I want to know the recent technological breakthroughs in solar cell and in cheap and commercial use of solar power……..
Pls also give me the links and some reports as soooon as possible…urg for chemistry project
March 4, 2007
3:46 pm #comment-7
Solar Cell?
Why are there emissions released in the production stage of solar cells?
January 29, 2008
5:25 am #comment-8
solar cell?
I want to run my home by the help of solar cell.I am now in a village .So how can i get it easyly?
May 10, 2009
2:05 pm #comment-9
What do they expect solar cell efficiency to increase to and what impact would this have on the use of solar?
Currently, solar cells are about 30% efficient. How can nanotechnology may change this in the future? What do they expect solar cell efficiency to increase to and what impact would this have on the use of solar cells?
February 1, 2010
7:58 pm #comment-10
What total solar cell area would you need to provide energy needs? Mastering Physics problem?
Solar cells convert the energy of incoming light to electric energy; a good quality cell operates at an efficiency of 15%. Each person in the United States uses energy (for lighting, heating, transportation, etc.) at an average rate of 11 kilowatts . Although sunlight varies with season and time of day, solar energy falls on the United States at an average intensity of 200 W/m^2.
Assuming you live in an average location, what total solar-cell area would you need to provide all of your energy needs with energy from the sun?