Shockley-Queisser analysis of the temperature-efficiency correlation of solar cells in the presence of non-radiative heat transfer

An empirical negative T cell  - η correlation has been widely applied, without careful justifications, to evaluate the efficiency (η) increase of solar cells due to their temperature (T cell ) decrease. Here, a framework is introduced to simultaneously compute T cell and η. This model confirms the negative T cell  - η correlation if the above-bandgap absorptivity (α I ) is not suppressed in the optimization of the sub-bandgap reflectivity (ρ II ) or the infrared emissivity, otherwise it may suggest a positive correlation. It further gives a guideline to enhance η of silicon cells under typical conditions: every 1% increase of α I is equivalent to a 57% increase of ρ II .