Limiting efficiency of intermediate band solar cells with spectrally selective reflectors

So far, theoretical efficiency limits for the intermediate band solar cell have been calculated under the assumption that the absorptivity of the solar cell is 1 for all photon energies larger than the smallest subband gap. In the present work, efficiency limits have been calculated under the assumption that the cell is covered by spectrally selective reflectors. The efficiency limit for the 1 sun 6000 K black body spectrum is found to increase from 46.8% to 48.5% and the limit for the AM1.5G spectrum (as defined by ASTM G173-03) is found to increase from 49.4% to 52.0%. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3466269]