If you don’t have a mortar and pestle, you could crush the berries in a small bowl or dish using a spoon or fork. You can use either frozen or fresh berries for this. If you use frozen berries, let them thaw first, so they’re easier to crush.
If you don’t have a petri dish, you can use a similar clean glass or plastic container. The water will help turn the berry paste into a liquid dye that will soak in more easily.
Titanium-oxide-coated glass slides are also known as ITO-coated (indium tin oxide coated) or FTO-coated (fluoride-doped tin oxide coated) slides. They have slightly different coatings but are both electrically conductive glass slides and with work equally well for this experiment. You can buy glass slides online. A set of 25 costs under $40 USD. Some slides have a transparent coating, in which case the side that feels rougher is the side that should go face-down.
The titanium oxide coating must be completely stained a deep reddish-purple color. If you can still see the white coating, place the slide back into the berry dye coated-side-down for another 10 minutes.
This dyed slide is your titanica electrode and will form half of your solar cell.
Note that this is a second, clean slide, different from the slide you dyed in the first part of the experiment. The conductive side is also sometimes marked with a “+” sign or may be a white color. You can also test a slide with a multimeter to find the conductive side. Set your multimeter to measure in Ohms and place both leads against 1 side of the glass. Repeat this for the other side. The side that measures closest to 0 Ohms is the conductive side. [7] X Research source You can use either an ITO-coated, FTO-coated, or TCO-coated (transparent conductive oxide coated) conductive glass slide for this.
You can use a piece of tape that is longer than the slide and stick the excess to the surface in front of you to stabilize the slide. Any kind of easily removable tape is fine for this. Just use what you have handy!
Graphite is a form of carbon and will act as a catalyst to facilitate the chemical reactions in your solar cell.
This carbon-coated glass slide is your counter electrode and forms the other half of your electrode.
If there is any excess solution near the edges of the slide, where there is no dyed coating, wipe it off with a clean tissue. You can buy a bottle of iodide electrolyte solution online for about $30 USD or less.
These 2 conductive faces of the slides, sandwiched together face-to-face, form the inside of your solar cell.
This is your completed solar cell. It will work until the electrolyte solution evaporates, at which point you can unclip the slides and add more solution or simply squeeze more solution onto 1 of the edges and let it seep in.
You can tell which slide is the dyed slide because you can see the reddish-purple tinted coating through the transparent outside. You can purchase a basic multimeter with alligator clip leads online for about $12 USD.
You can tell which slide is the graphite coated slide because it will look grayish when you look through that side of the solar cell.
As an alternative to natural sunlight, you can use an incandescent or halogen lamp. The electricity output will vary based on the strength of the light source, but this type of homemade solar cell typically generates between about 0. 4 and 0. 6 volts of electricity.
