Ultrathin Flexible Graphene Film: An Excellent Thermal Conducting Material with Efficient EMI Shielding

As the portable device hardware has been increasing at a noticeable rate, ultrathin thermal conducting materials (TCMs) with the combination of high thermal conductivity and excellent electromagnetic interface (EMI) shielding performance, which are used to efficiently dissipate heat and minimize EMI problems generated from electronic components (such as high speed processors), are urgently needed. In this work, graphene oxide (GO) films are fabricated by direct evaporation of GO suspension under mild heating, and ultrathin graphite‐like graphene films are produced by graphitizing GO films. Further investigation demonstrates that the resulting graphene film with only ≈8.4 μm in thickness not only possesses excellent EMI shielding effectiveness of ≈20 dB and high in‐plane thermal conductivity of ≈1100 W m‐1 K‐1, but also shows excellent mechanical flexibility and structure integrity during bending, indicating that the graphitization of GO film could be considered as a new alternative way to produce excellent TCMs with efficient EMI shielding. The graphitization of graphene oxide films can lead to the formation of graphite‐like graphene films, which not only display a remarkable combination of excellent electromagnetic interface (EMI) shielding effectiveness and high in‐plane thermal conductivity, but also show excellent mechanical flexibility, indicating a novel promising candidate for excellent thermal conducting materials with efficient EMI shielding.