The corresponding quantum efficiencies (QE) are shown in Fig. 5, where we show QEs for both the cells. Once again, the QE for the cell deposited on the photonic substrate is significantly higher than for the cell deposited substrate is significantly higher than for the cell deposited on the planar PEN substrate. In Fig. 6, we show the ratio of increased absorption for the photonic cell compared with the planar cell, calculated from the QE curves, vs. wavelength. There are characteristic resonnances for the photonic cell, as expected from the theory [10]. The maximum enhancement is about a factor of 8 so far in this initial stucture. Further experiments to enhance this factor are in progress.