The document explains how a berry solar cell works, detailing the process of converting light energy into electricity using berry juice, specifically the cyanidin molecule. It describes the roles of titanium dioxide and electrodes in capturing and directing the flow of electrons generated by light excitation. Additionally, it mentions the need for replenishing berry juice with iodide to maintain the solar cell's function, supported by a catalyst made from carbon.

1. How the Berry Solar Cell Works
by Jimmy O'Dea
Cornell University

2. Please use and share this presentation widely!
Attribute Jimmy O’Dea and provide this link to the presentation:
http://www.slideshare.net/jimmyodea (send me messages with any questions)
This work is licensed under a Creative Commons Attribution-NonCommercialShareAlike 4.0 International License.
See: http://creativecommons.org/licenses/by-nc-sa/4.0/deed.en_US
(attribute me, don’t make $ off the presentation, and share modified versions of the presentation with the same license)
Teachers: for a lending kit to build the berry solar cell in your classroom, see:
http://www.ccmr.cornell.edu/education/lendinglibrary/

3. How the Berry Solar Cell Works

4. How the Berry Solar Cell Works
y
an

5. How the Berry Solar Cell Works
y
an
First, let's talk about how
any solar cell works…

6. A solar cell is a device that converts
the energy in light into electricity

7. A solar cell is a device that converts
the energy in light into electricity.

8. A solar cell is a device that converts
the energy in light into electricity.
Let's see how this works...

9. How the Berry Solar Cell Works
y
an

10. How the Berry Solar Cell Works
y
an
Energy from light
(made up of photons)
excites electrons
in atoms in the solar cell.

11. How the Berry Solar Cell Works
y
an
Energy from light
(made up of photons)
excites electrons
in atoms in the solar cell.

12. How the Berry Solar Cell Works
y
an
Energy from light
(made up of photons)
excites electrons
in atoms in the solar cell.

13. How the Berry Solar Cell Works
y
an
We can collect the excited
and route them through a
device we want to power,
like a light bulb.

14. How the Berry Solar Cell Works
y
an
We can collect the excited
and route them through a
device we want to power,
like a light bulb.

15. How the Berry Solar Cell Works
y
an
When the negatively charged
leave the solar cell,
positive charges are left behind.

16. How the Berry Solar Cell Works
y
an
When the negatively charged
leave the solar cell,
positive charges are left behind.
are attracted
to and flow to
the ( ) charge.
+

17. How the Berry Solar Cell Works
y
an
When the negatively charged
leave the solar cell,
positive charges are left behind.
are attracted
to and flow to
the ( ) charge.
+
The flow of
is what we
call electricity!

18. How the Berry Solar Cell Works
Now to the berry solar cell…

19. How the Berry Solar Cell Works
So if we want to use light to create flowing
we first need a material that absorbs light.
This is what the berry juice will do.
,

20. How the Berry Solar Cell Works
So if we want to use light to create flowing
we first need a material that absorbs light.
This is what the berry juice will do.
,

21. How the Berry Solar Cell Works
There are many different molecules in berry
juice (such as H2O). The molecule that absorbs
the light in berry juice is called cyanidin.

22. How the Berry Solar Cell Works
There are many different molecules in berry
juice (such as H2O). The molecule that absorbs
the light in berry juice is called cyanidin.

23. How the Berry Solar Cell Works
When the berry juice absorbs light, an
in the berry juice molecule is excited.
For this excited
to be of any use,
we need to quickly “pull” it away from
the berry juice molecule. We do that with
a chemical called titanium dioxide.

24. How the Berry Solar Cell Works
When the berry juice absorbs light, an
in the berry juice molecule is excited.
For this excited
to be of any use,
we need to quickly “pull” it away from
the berry juice molecule. We do that with
a chemical called titanium dioxide.

25. How the Berry Solar Cell Works
When the berry juice absorbs light, an
in the berry juice molecule is excited.
For this excited
to be of any use,
we need to quickly “pull” it away from
the berry juice molecule. We do that with
a chemical called titanium dioxide.

26. How the Berry Solar Cell Works
Now we need something that will
collect the
from the titanium dioxide.
This something is called an electrode.
Our electrode is a glass slide with
a conductive and transparent coating.

27. How the Berry Solar Cell Works
Now we need something that will
collect the
from the titanium dioxide.
This something is called an electrode.
Our electrode is a glass slide with
a conductive and transparent coating.

28. How the Berry Solar Cell Works
Now we need something that will
collect the
from the titanium dioxide.
This something is called an electrode.
Our electrode is a glass slide with
a conductive and transparent coating.

29. How the Berry Solar Cell Works
Now we need something that will
collect the
from the titanium dioxide.
This something is called an electrode.
Our electrode is a glass slide with
a conductive and transparent coating.

30. How the Berry Solar Cell Works
Now we need something that will
collect the
from the titanium dioxide.
This something is called an electrode.
Our electrode is a glass slide with
a conductive and transparent coating.

31. How the Berry Solar Cell Works
Now we need something that will
collect the
from the titanium dioxide.
This something is called an electrode.
Our electrode is a glass slide with
a conductive and transparent coating.
500 nm
Fluorine doped tin oxide coating on
a glass slide. Image: Jimmy O’Dea
Here's what the coating on the glass
slide looks like under an electron
microscope at x20,000 magnification.

32. How the Berry Solar Cell Works

33. How the Berry Solar Cell Works
Our collected
flow through our
light bulb and into an electrode at
the other side of the solar cell.

34. How the Berry Solar Cell Works
But taking
from the berry juice
molecules makes them positively charged
and less likely to give up another .

35. How the Berry Solar Cell Works
So we replenish the berry juice
molecules with
through a chemical
reaction with a solution of iodide.

36. How the Berry Solar Cell Works
So we replenish the berry juice
molecules with
through a chemical
reaction with a solution of iodide.

37. How the Berry Solar Cell Works
But this reaction is slow, so we
speed it up (catalyze it) with a
coating of carbon (from either
candle soot or a graphite pencil).

38. How the Berry Solar Cell Works
But this reaction is slow, so we
speed it up (catalyze it) with a
coating of carbon (from either
candle soot or a graphite pencil).

39. How the Berry Solar Cell Works
But this reaction is slow, so we
speed it up (catalyze it) with a
coating of carbon (from either
candle soot or a graphite pencil).

40. How the Berry Solar Cell Works
But this reaction is slow, so we
speed it up (catalyze it) with a
coating of carbon (from either
candle soot or a graphite pencil).

41. How the Berry Solar Cell Works
But this reaction is slow, so we
speed it up (catalyze it) with a
coating of carbon (from either
candle soot or a graphite pencil).

42. How the Berry Solar Cell Works
And that's how the berry
solar cell works!