Facile Preparation of Highly Transparent Conducting Nanopaper with Electrical Robustness

Nanocellulose paper-based transparent conducting material, an important primary component of future green electronics, has been considered one of the most exciting and salient materials in next-generation flexible electronic devices. It remains a challenge to facilely fabricate highly transparent conducting nanopaper materials with electrical robustness, a necessity as they play quite an important role in the display and/or optically related fields of flexible electronics. Here, we facilely fabricate a highly transparent (transmittance of ∼94.5% at 550 nm) and conductive (ionic conductivity of ∼0.13 S·m–1) nanopaper (TCNP) by in situ photopolymerization of the conductive polymerizable deep eutectic solvent (PDES) monomer on the nanopaper substrate made of cellulose nanofibrils. The TCNP also shows excellent optical and electrical durability after bending–recovering over 6000 cycles at a 150° bending angle. Furthermore, we have demonstrated the practical suitability of the TCNP through assembly in flexible electroluminescent devices. In particular, PDES, as a conductive ink, can construct customized electroluminescent devices. This study provides a facile preparation strategy of the TCNP for optoelectronics that are promising for future flexible electronics.