Solar Cell and UV Light

derek50

I'm looking for a cheap solar cell for an experiment that we're doing on different sunblock lotions.

Will a clear sunblock lotion (say spf 50) affect the ability for a common solar cell to produce electricity?

If the answer to the first question is no, is there a solar cell that does use UV light to produce electricity?

Thanks,

Derek

derek50

Does anyone know of a basic solar cell that is affected by sunblock?

James Leighe

I think sunblock works by having tiny pieces of reflective material in it (e.g. metal flakes)... so yes, it would also block other wavelengths of light as well. (I could definitely be wrong here if sunblock does not work how I assume)

derek50

I know that the typical sunscreen blocks the harmful UV light that causes skin damage. I also know that a solar cell converts light into electricity. What I don't know is if a solar cell converts the UV spectrum of sun light into electricity as well as the normal visibal light. Even if a solar cell does convert UV light into electricity is it a substantial amount that could be detected if a sun screen is used to block the UV light.

Thanks for the reply.

Bob S

There are a lot of vacuum photodiodes that have a response down to about 3000 Angstroms. My favorite was the RCA 935 vacuum photodiode. These had an extremely low leakage current, because the anode (plate) and cathode (photosensitive surface) are at opposite ends of the tube. See
http://ems.calumet.purdue.edu/chemph...ototube935.pdf
Bob S

derek50

I think that Bob has been conducting some alcohol experiments.

mgb_phys

A solar cell probably isn't a very good test of UV absorption.
UV is absorbed in the very top layers of silicon (because of the high-energy, short wavelength). It's possible that adding a sunscreen could have an optical effect, acting as an anti-reflection coating, or reflecting photons back into the cell or changing the surface properties of the silicon that would be a bigger effect than you are trying to measure.

Interestingly a lot of the techniques for improving the UV sensitivty of CCDs for astronomy were discovered from accidental contamination of the surface of the silicon with fingerprints, oil, maker pens etc.

derek50

Thanks for the info. I've been finding the same information but I was hoping to find a solar cell that could power a small car or something. Then we could measure the distance that the car would travel within a given amount of time as the way to measure the effectiveness of the different sun screens. Oh well. Not a big deal. I've found a UV meter and some UV sensitive beads that change colors when exposed to UV light. Not as cool as a solar powered car but still cool.

Thanks