We demonstrate tunable mid-infrared (MIR) beam steering devices based on multilayer graphene-dielectric metamaterials. The effective refractive index of such metamaterials can be manipulated by changing the chemical potential of each graphene layer. This can arbitrarily tailor the spatial distribution of the phase of the transmitted beam, providing mechanisms for active beam steering. Three dif...

We developed a simple, scalable and high-throughput method for fabrication of large-area three-dimensional rose-like microflowers with controlled size, shape and density on graphene films by femtosecond laser micromachining. The novel biomimetic microflower that composed of numerous turnup graphene nanoflakes can be fabricated by only a single femtosecond laser pulse, which is efficient enough ...

In this report, we succeed in constructing a hybrid three-dimensional (3D) nanocomposite film by alternatively assembling the graphene nanosheets modified by ionic liquid (IL) and Pt nanoparticles (Pt NPs). In this strategy, an imidazolium salt-based ionic liquid (IS-IL)-functionalized graphene was synthesized by covalently binding 1-(3-aminopropyl)-3-methylimidazolium bromide onto graphene nan...

Large-area graphene grown by chemical vapor deposition (CVD) is a promising candidate for transparent conducting electrode applications in flexible optoelectronic devices such as light-emitting diodes or organic solar cells. However, the power conversion efficiency (PCE) of the polymer photovoltaic devices using a pristine CVD graphene anode is still not appealing due to its much lower conducti...

The high thermal conductivity of graphene and few-layer graphene undergoes severe degradations through contact with the substrate. Here we show experimentally that the thermal management of a micro heater is substantially improved by introducing alternative heat-escaping channels into a graphene-based film bonded to functionalized graphene oxide through amino-silane molecules. Using a resistanc...

High-yield production of few-layer graphene flakes from graphite is important for the scalable synthesis and industrial application of graphene. However, high-yield exfoliation of graphite to form graphene sheets without using any oxidation process or super-strong acid is challenging. Here we demonstrate a solution route inspired by the lithium rechargeable battery for the high-yield (>70%) exf...

The transfer of chemical vapour deposited graphene from its parent growth catalyst has become a bottleneck for many of its emerging applications. The sacrificial polymer layers that are typically deposited onto graphene for mechanical support during transfer are challenging to remove completely and hence leave graphene and subsequent device interfaces contaminated. Here, we report on the use of...

Few-layer graphene has been prepared by electrochemical intercalation of graphite cathode using Na/ dimethyl sulfoxide complexes as intercalation agent. By adding thionin acetate salt into the electrolyte, the exfoliated graphite is stabilized and further exfoliated into few-layer graphene. Raman and X-ray photoelectron spectra indicate that the graphene material has lower content of defects an...

We report the electrochemical properties of pristine monolayer, double layer and few-layer (termed quasi-) graphene grown via CVD and transferred using PMMA onto an insulating substrate (silicon dioxide wafers). Characterisation has been performed by Raman spectroscopy, optical spectroscopy, Atomic Force Microscopy and X-ray Photoelectron Spectroscopy, revealing 'true' pristine single-layer gra...

The interaction between single-walled carbon nanotubes (SWNTs) and graphene were studied with first-principles calculations. Both SWNTs and single-layer graphene (SLG) or double-layer graphene (DLG) display more remarkable deformations with the increase of SWNT diameter, which implies a stronger interaction between SWNTs and graphene. Besides, in DLG, deformation of the upper-layer graphene is ...