The Shockley-Queisser limit for the maximum possible efficiency of a solar cell (black), and the inevitable losses that limit it (other colors). The black height is energy that can be extracted as useful electrical power; the pink height is energy of below-bandgap photons; the green height is energy lost when hot photogenerated electrons and holes relax to the band edges; the blue height is energy lost in the tradeoff between low radiative recombination versus high operating voltage. The curves are all wiggly because of IR absorption bands in the atmosphere: I used the actual AM1.5G solar spectrum data. I cross-checked the black curve with independently-calculated ones and they agree to high accuracy, <a rel="nofollow" class="external autonumber" href="http://www.opticsinfobase.org/abstract.cfm?URI=OSE-2010-SWA1">[1]</a> <a rel="nofollow" class="external autonumber" href="http://www.opticsinfobase.org/abstract.cfm?URI=OSE-2010-SWC4">[2]</a>. The other curves besides the black curve are not published in exactly this form to my knowledge, but it's a straightforward part of the same calculation.
<a href="//commons.wikimedia.org/wiki/User:Sbyrnes321" title="User:Sbyrnes321">Sbyrnes321</a>
2011-02-17
<span class="int-own-work" lang="en">Own work</span>