The electric field cavity array effect of 2D nano-sieves

For the upsurge of high breakdown strength ( $${{{{{{\rm{E}}}}}}}_{{{{{{\rm{b}}}}}}}$$ E b ), efficiency ( $${{{{{\rm{\eta }}}}}}$$ η ), and discharge energy density ( $${{{{{{\rm{U}}}}}}}_{{{{{{\rm{e}}}}}}}$$ U e ) of next-generation dielectrics, nanocomposites are the most promising candidates. However, the skillful regulation and application of nano-dielectrics have not been realized so far, because the mechanism of enhanced properties is still not explicitly apprehended. Here, we show that the electric field cavity array in the outer interface of nanosieve-substrate could modulate the potential distribution array and promote the flow of free charges to the hole, which works together with the intrinsic defect traps of active Co3O4 surface to trap and absorb high-energy carriers. The electric field and potential array could be regulated by the size and distribution of mesoporous in 2-dimensional nano-sieves. The poly(vinylidene fluoride-co-hexafluoropropylene)-based nanocomposites film exhibits an $${{{{{{\rm{E}}}}}}}_{{{{{{\rm{b}}}}}}}$$ E b of 803 MV m−1 with up to 80% enhancement, accompanied by high $${{{{{{\rm{U}}}}}}}_{{{{{{\rm{e}}}}}}}$$ U e = 41.6 J cm−3 and $${{{{{\rm{\eta }}}}}}\,$$ η ≈ 90%, outperforming the state-of-art nano-dielectrics. These findings enable deeper construction of nano-dielectrics and provide a different way to illustrate the intricate modification mechanism from macro to micro.