Question:
One of the newest and most promising fields of photovoltaics is found in the use of photovoltaic molecules. From what I understand there is a wide selection of these types of molecules that use the energy absorbed from photons to generate an electric current. Even though I understand how typical, silicon based solar cells work, I have not understood how it is possible for a single molecule to achieve the same task. In other words, how exactly do these molecules absorb photons and use that energy to create a current? How would we harvest that current on such a small scale? What materials are they made out of that allow them to accomplish this?
Replies:
Any number of molecules can be designed to absorb light, and convert
it into electrical energy. The way these molecules do this is to have
the right kind of structure to be able to absorb a photon (of light)
and collect its energy by moving into a more energetic (excited)
state. Most organic photovoltaic molecules use conjugated
carbon-carbon bonds to do this. The excited state then can be used to
create an electric current that can be collected. There are many
details of how this works that I am skipping over -- I am unsure how
much physics or organic chemistry you have (feel free to ask more
questions if you want more details).
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