Stacking sequence effect on the electrical and optical properties of multistacked flexible IZO-Ag-IZO electrodes

We investigated the stacking sequence effect of indium zinc oxide (IZO)-Ag and IZO-Ag-IZO on the characteristics of multistacked flexible transparent electrodes for organic photovoltaics. In spite of the similar sheet resistances of the IZO-Ag and IZO-Ag-IZO stacked electrodes, the optical transparency of the latter is much higher than that of the former in the wavelength region of 400-800 nm due to the effective antireflection in the symmetric oxide-Ag-oxide structure. Furthermore, the flexible organic solar cells (OSCs) fabricated on the IZO-Ag-IZO-stacked multilayer electrode showed a higher power conversion efficiency than those fabricated on the IZO-Ag-stacked multilayer electrode due to the higher optical transparency of the former electrode in the main absorption region of the poly(3-hexylthiophere) and 1-(3-methoxycarbonyl)- propyl-1-phenyl-(6,6) C₆₁ layers. This indicates that the multistacked electrode with the IZO-Ag-IZO sequence is more beneficial than that with the IZO-Ag sequence for low resistance and high transparency electrodes in flexible OSCs.