Figure 6
(a) Optical absorption of planar and square grating structures with a pillar height of 200 nm. The organic active layer that includes square pillars of height 200 nm shows an 8.8% optical absorption enhancement (averaged over the considered wavelength range). (b) Electrical properties of the planar reference solar cell (black line), the grating structure with optical generation profile equalized to the planar cell (blue line) and the solar cell with optical generation profile calculated by the FDTD method (red line). The power conversion efficiency for OSCs having a nano-structured grating enhances, exclusively due to the improved charge collection efficiency. By incorporating the 8.8% optical enhancement within the solar cell, the electrical properties in terms of J sc, FF and thus PCE (28.5%) improve even further.
