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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."
Hans-Joachim Queisser (born 6 July 1931, Berlin, Germany) is a solid-state physicist. He is best known for co-authoring the 1961 work on solar cells that detailed what is today known as the Shockley–Queisser limit , now considered the key contribution in this field.
They assumed no carriers were collected at the IB and that the device was under full concentration. [1] They found the maximum efficiency to be 63.2%, for a bandgap of 1.95eV with the IB 0.71eV from either the valence or conduction band. [1] Under one sun illumination the limiting efficiency is 47%. [2]
English: The Shockley-Queisser limit for the maximum possible efficiency of a solar cell. The x-axis is the bandgap of the solar cell, the y-axis is the highest possible efficiency (ratio of electrical power output to light power input). (Assumes a single-junction solar cell under unconcentrated light, and some other assumptions too.)
The Shockley equation doesn't model noise (such as Johnson–Nyquist noise from the internal resistance, or shot noise). The Shockley equation is a constant current (steady state) relationship, and thus doesn't account for the diode's transient response , which includes the influence of its internal junction and diffusion capacitance and ...
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.
Using concentrations on the order of 500 to 1000, meaning that a 1 cm 2 cell can use the light collected from 0.1 m 2 (as 1 m 2 equal 10000 cm 2), produces the highest efficiencies seen to date. Three-layer cells are fundamentally limited to 63%, but existing commercial prototypes have already demonstrated over 40%.
William Bradford Shockley Jr. (February 13, 1910 – August 12, 1989) was an American inventor, physicist, and eugenicist.He was the manager of a research group at Bell Labs that included John Bardeen and Walter Brattain.