Highly smooth, stable and reflective Ag-paper electrode enabled by silver mirror reaction for organic optoelectronics

Cellulose paper can be exploited for future electronics due to its flexibility, versatility, and low cost. However, the rapid fabrication of paper electrodes with a smooth surface and durability remains a challenge. In this paper, we report the fabrication of conducive, smooth and stable Ag electrodes on common printing paper through solution-processed silver mirror reaction. The rough cellulose substrate was modified with polypropylene to form an interconnected two-network structure yielding a super-flat surface and significantly better mechanical performance than paper or plastic. Based on the modified paper, a controllable spin-coating silver mirror reaction process was developed to form a smooth silver coating. The obtained Ag-paper electrode has a surface roughness without big particles over 50 nm and a strong barrier ability against moisture and solvents, while retaining the features of common cellulose paper. The successful solution-processed application of organic solar cells and organic light-emitting diodes based on silver electrode is demonstrated, showing the material's potential in future flexible electronics.