- #1
heynow999
- 6
- 2
Homework Statement
how many photons does the sun generate to knock one electron across the bandgap in a PV panel? I am doing a college level night school course on Photovoltaics and I have to do a short presentation on photons and how they produce useable energy. I thought it would be interesting to work out this question. Assume a panel is %15 efficient and %40 of the photons are blocked by the atmosphere.
Homework Equations
The Attempt at a Solution
I assume it takes one photon to knock one electron across the bandgap. So working backwards, the panel is %15 efficient so 1/.15=6.66. Next, we lost %40 to the atmosphere so 6.66/.4=16.66 so 16.66 photons would have to strike the atmosphere to knock one electron across the bandgap. I am stumped by the next step but I know it will be a huge number. Let's assume no photons are lost in the trip from the sun. Does this even make sense?
Thanks