Coordination-Regulated Ultrathin Silver Electrodes for High-Efficiency Semitransparent Organic Solar Cells

In semitransparent organic solar cells (ST-OSCs), island-like growth of ultrathin metal electrodes can lead to electrical and optical losses. Here, we demonstrate that amine-functionalized perylene diimide (PDINN), a commonly used electron interfacial layer, also acts as a dense nucleation layer for ultrathin silver (Ag) and enables a continuous, smooth film with a lower percolation threshold and higher visible-light transmittance. Strong PDINN-Ag interactions, with a binding energy of -4.39 eV and adsorption energy of -4.68 eV quantified by density functional theory calculations, significantly regulate Ag nucleation, suppress Ag migration and oxidation, thereby improving the stability of transparent electrodes. By optimizing the deposition rate and integrating a MoO₃ anti-reflective coating layer, the resulting transparent electrode achieves a low sheet resistance (R_s) of 6.0 Ω sq^-1, a high average visible transmittance (AVT) of 89.2%, and an outstanding figure of merit (FoM) of 613, together with excellent environmental stability. The ST-OSC incorporating this electrode reaches a light utilization efficiency (LUE) of 5.12%. This work provides a facile and scalable strategy for fabricating transparent electrodes with high transmittance, conductivity, and excellent stability, advancing the development of next-generation ST-OSCs.