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The Shockley–Queisser limit, zoomed in near the region of peak efficiency. In a traditional solid-state semiconductor such as silicon, a solar cell is made from two doped crystals, one an n-type semiconductor, which has extra free electrons, and the other a p-type semiconductor, which is lacking free electrons, referred to as "holes."
The Shockley-Queisser limit for the efficiency of a single-junction solar cell under unconcentrated sunlight. This calculated curve uses actual solar spectrum data, and therefore the curve is wiggly from IR absorption bands in the atmosphere. This efficiency limit of about 34% can be exceeded by multijunction solar cells.
The theoretical performance of a solar cell was first studied in depth in the 1960s, and is today known as the Shockley–Queisser limit. The limit describes several loss mechanisms that are inherent to any solar cell design. The first are the losses due to blackbody radiation, a loss mechanism that affects any material object above absolute zero.
Breakdown of the causes for the Shockley-Queisser limit. The black height is Shockley-Queisser limit for the maximum energy that can be extracted as useful electrical power in a conventional solar cell. However, a multiple-exciton-generation solar cell can also use some of the energy in the green area (and to a lesser extent the blue area ...
Third-generation photovoltaic cells are solar cells that are potentially able to overcome the Shockley–Queisser limit of 31–41% power efficiency for single bandgap solar cells. This includes a range of alternatives to cells made of semiconducting p-n junctions ("first generation") and thin film cells ("second generation").
The numbers are normally not similar as you suggest. But in any case, f c cannot be more than 1, and the upper limit (the Shockley-Queisser limit) requires taking f c = 1. Eric Kvaalen 19:05, 6 September 2016 (UTC) Yes, virtually all above-gap photons come from recombination, but not all recombinations create above-bandgap photons.
The Shockley–Queisser limit for the efficiency of a single-junction solar cell under unconcentrated sunlight at 273 K. This calculated curve uses actual solar spectrum data, and therefore the curve is wiggly from IR absorption bands in the atmosphere. This efficiency limit of ~34% can be exceeded by multijunction solar cells.
The Shockley–Queisser limit gives the maximum possible efficiency of a single-junction solar cell under un-concentrated sunlight, as a function of the semiconductor band gap. If the band gap is too high, most daylight photons cannot be absorbed; if it is too low, then most photons have much more energy than necessary to excite electrons ...