3D curved graphene realizes high-density packaging and miniaturization of electronic devices
A group of researchers from Tohoku University, Okayama University of Science, Osaka University, University of Tsukuba, The University of Tokyo, and Johns Hopkins University (USA) has clarified that 3D graphene has more excellent properties than 2D graphene and how the curved 3D surface affects the properties of graphene.
Graphene, a 2D atomic-layer material, has excellent electrical and thermal conductivity, chemical and mechanical resistance, and ultra-wide absorption spectrum range, but there are limitations in its applications. Thus, researchers have tried to fabricate 3D graphene for practical applications through assembly and integration of 2D graphene sheets into a 3D form.
To amplify the device performances of 2D graphene, 3D graphene nanoarchitectures (3D graphene) are constructed. 3D structures provide graphene materials with high surface areas as well as large pore volumes through the combination of the 3D porous structures and the excellent intrinsic properties of graphene, but it was challenging to preserve the characteristics of 2D graphene (such as Dirac fermions and 2D electron transport properties) in 3D graphene. 3D graphene’s mechanical properties vastly differ from 2D graphene.
This group fabricated 3D nanoporous graphene with quasiperiodic structures and different curvature radii by folding a single 2D graphene sheet into a 3D structure with bicontinuous and open porous structures (graphene sponge).
They investigated the electronic states and electrical properties of graphene sponge with pore size (curvature radius) ranging from 25 to 1000 nm to investigate the influence of 3D curved surfaces on the fundamental physical properties of graphene. As a result, they found that 3D graphene fully preserved the 2D electronic properties of graphene and that the highly curved 3D surface significantly affected the properties of 2D graphene.
A 3D graphene sponge constructed by a single graphene sheet can fully preserve the 2D electronic properties of graphene with a large accessible specific surface area and high areal mass loading for a wide range of functional and structural applications.
This group’s achievements showed design guidelines for devices using graphene (such as photo detectors, electrode catalysis, and capacitors), which require surface area, electric conductivity, and carrier mobility.
This study experimentally unveiled the curvature dependence of electronic states of the graphene sponges, providing new insights into the 2D electron kinetics in 3D nanoarchitecture with intrinsic curvature and essential knowledge to amplify various excellent properties of graphene for 3D device applications.
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The article, “Dirac Fermion Kinetics in 3D Curved Graphene,” was published in Advanced Materials at DOI: https://doi.org/10.1002/adma.202005838.
