Spiral growth of various nanomaterials including some two-dimensional (2D) transition metal dichalcogenides had recently been experimentally realized using chemical vapor deposition (CVD). However, such growth that is driven by screw dislocation remained elusive for graphene and are rarely discussed because of the use of metal catalysts. In this work, we show that formation of few-layer graphene (FLG) with a spiral structure driven by screw dislocation can be obtained alongside with FLG having a concentric layered structure formed by interfacial nucleation (nucleation at the graphene/Cu interface) using a Cu-catalyzed ambient pressure CVD. Unlike commonly reported FLG grown by interfacial nucleation where the second layer is grown independently beneath the first, the growth of a spiral structure adopts a top growth mechanism where the top layers are an extension from the initial monolayer which spirals around an axial dislocation in self-perpetuating steps. Since the same atomic orientation is preserved, the subsequent spiraling layers are stacked in an oriented AB-stacked configuration. This contrasts with FLG formed by interfacial nucleation where turbostratic stacking of the entire adlayer may exist. In both growth scenarios, the second layer (either top or bottom) can grow across the grain boundaries of the initial monolayer domains, forming partial regions with turbostratic stacking configuration due to weak interlayer van der Waals interactions. The unique interlayer coupling of FLG spirals which enable superior conductivity along the normal of the 2D crystal with spiraling trajectories, are expected to have new and interesting nanoscale applications.

A flexible THz wave absorber based on G-VACNT hybrids is demonstrated for ultra-broadband THz wave absorption and imaging applications.

Orientation controlled hexagonal boron nitride (h-BN) films exhibit excellent mechanical and thermal properties, making them attractive for diverse applications.

Construction of macroscopic 3D architectures of graphene is crucial to harness the advantageous properties of planar 2D graphene and to enable integration to many conventional and novel applications. Ideally, the 3D structure of graphene should be free of defects, covalently interconnected, and can be produced at large‐scale. Among various assembly techniques, fabrication using chemical vapor deposition (CVD) enables the production of high‐quality graphene where selection of template is the key that determines its consequent crystalline quality and structural morphology. Herein, a new method is presented to synthesize high‐quality porous graphene film by incorporating an in situ reduction–oxidation cycling treatment to generate micrometer‐sized pores on commercial Ni foil using an all‐CVD process route. Owing to the unique morphological features of the modified Ni template, the graphene film exhibits a holey surface with large‐area exterior skin coverage of >94% and many interconnected ligaments within its porous interior. This extraordinary configuration gives rise to superior in‐plane electrical conductivity despite its low density. In comparison to state‐of‐the‐art materials for electromagnetic interference shielding, this porous graphene film is among the best performing materials with a specific shielding effectiveness of >550 dB cm3 g−1 and absolute effectiveness of >220 000 dB cm2 g−1.

In terahertz (THz) quasi‐optical systems, the real‐time profiling and visualization of THz beams is of great importance for beam focusing and collimation applications. Herein, a cost‐effective and room‐temperature‐operated THz imaging device for this purpose is demonstrated experimentally using a flexible and broadband THz absorber based on a vertically aligned carbon nanotube (VACNT) array. Excellent THz absorption performances with an average power absorptance >96.8% are achieved within 0.1 and 2.5 THz. The energy of the incident THz wave is absorbed by the THz absorber and converted into heat that will re‐radiate and can be detected by an infrared (IR) camera as a result of the THz‐to‐IR conversion mechanism. Real‐time THz beam imaging and monitoring applications are demonstrated by a series of experiments at both 0.1 and 0.3 THz, providing an alternative approach for real‐time beam profiling and monitoring of THz waves.