Novel Bimodal Silver Nanowire Network as Top Electrodes for Reproducible and High-Efficiency Semitransparent Organic Photovoltaics

摘要

Semitransparent organic photovoltaics (ST-OPVs) provide a potentially facile route for some applications in building integrated photovoltaics. One of the challenges in developing large-scale, printable ST-OPVs is to address the need for high-performance and fully solution-processed top electrodes, allowing the replacement of the evaporated thin metallic films (Ag, Au, and Al). Silver nanowire (AgNW) is considered a promising candidate for the substitution due to its excellent transparency, conductivity, and solution processability. Herein, a novel bimodal AgNW (AgNW-BM) electrode is reported, comprising AgNWs of two different aspect ratios. It is shown that the AgNW-BM film achieves lower sheet resistance and higher visible transmittance than each monodisperse AgNW film, respectively. Furthermore, ST-OPVs based on PTB7-Th:IEICO-4F with AgNW-BMtop electrodes are fabricated, which can obtain a maximum power conversion efficiency (PCE) of 7.49% with an average visible transmittance (AVT) of 33%. The ST-devices also demonstrate an enhanced reproducibility and excellent color-rendering index of 90. In addition, the bimodal top electrode is successfully implemented in the PM6:Y6 system with a higher PCE of 9.79% and with an AVT of 23%, demonstrating the universality for various semiconductor systems. Our work provides a simple strategy to realize fully solution-processed, highly efficient ST-OPVs.