ITO Breakers: Highly Transparent Conducting Polymer/Metal/Dielectric (P/M/D) Films for Organic Solar Cells

Abstract

Ormoclear/Ag/WO3 (OAW) films with ultrahigh transparency are designed for application in organic solar cells (OSCs). When the thicknesses of Ag and WO3 are fixed at 8 nm and 30 nm, respectively, excellent transparency that is independent of Ormoclear thickness is successfully achieved by employing soft materials instead of inorganic dielectrics. Oxygen plasma treatment prior to the deposition of Ag introduces the polar functional groups on the Ormoclear surface, which results in increasing the surface hydrophilicity, thereby enhancing the wettability of Ag. From the surface modification, OAW exhibits low sheet resistance (4.8 ohm sq(-1)), high transmittance of up to 96.3% at 535 nm, and enhanced efficiency of 7.63% of OSCs. Moreover, nanoimprint lithography is used to prepare a well-ordered nanopatterned OAW with dimple diameter of 90 nm, leading to further increase in photocurrent density by 17%, compared to that with a planar indium tin oxide (ITO) electrode.