Influence of the overlap between the absorption coefficients on the efficiency of the intermediate band solar cell

This paper studies the effects of the overlap between the three absorption coefficients involved in the operation of the intermediate band solar cell on the performance of this novel photovoltaic converter. Although an arbitrary overlap, in general, reduces the limiting efficiency of the intermediate band solar cell (for example from 57.29% to 32.56% under 1000 suns), its impact can be minimized and almost suppressed when the absorption coefficients increase with energy, and light confinement is used. Another important consequence derived from the overlap between the absorption coefficients is that the thickness of the intermediate band solar cell, even using detailed balance arguments and in contrast to the detailed balance model of the conventional single-gap solar cell, now becomes a parameter to be optimized.