Facile fabrication of ultrathin graphene papers for effective electromagnetic shielding

Ultrathin electromagnetic interference (EMI) shielding materials promise great application potential in portable electronic devices and communication instruments. Lightweight graphene-based materials have been pursued for their exclusive microstructures and unique shielding mechanism. However, the large thickness of the current low-density graphene-based composites still limits their application potential in ultrathin devices. In this work, a novel approach has been taken to use conductive graphene paper (GP) in the fabrication of ultrathin EMI shielding materials. The as-prepared flexible GPs exhibit highly effective shielding capabilities, reaching similar to 19.0 dB at similar to 0.1 mm in thickness and similar to 46.3 dB at similar to 0.3 mm in thickness, thus the thinnest GPs having the best shielding performance among graphene-based shielding materials. Double-layered shielding attenuators have been designed and fabricated for a high shielding performance of up to similar to 47.7 dB at a GP thickness of similar to 0.1 mm. Mechanistically, the high performance should be due to Fabry-Perot resonance, which is unusual in carbon-based shielding materials. The preparation of conductive GPs of superior shielding performance is relatively simple, amenable to largescale production of ultrathin materials for EMI shielding and electromagnetic attenuators, with broad applications in lightweight portable electronic devices.