Layer‐by‐Layer Assembled Heteroatom‐Doped Graphene Films with Ultrahigh Volumetric Capacitance and Rate Capability for Micro‐Supercapacitors

Highly uniform, ultrathin, layer-by-layer heteroatom (N, B) co-doped graphene films are fabricated for high-performance on-chip planar micro-supercapacitors with an ultrahigh volumetric capacitance of ∼488 F cm(-3) and excellent rate capability due to the synergistic effect of nitrogen and boron co-doping.