All Outputs (40)

Photo-quantum Hall effect and light-induced charge transfer at the interface of graphene/InSe heterostructures (2018)
Journal Article

The transfer of electronic charge across the interface of two van der Waals crystals can underpin the operation of a new class of functional devices. Amongst van der Waals semiconductors, an exciting and rapidly growing development involves the “post... Read More about Photo-quantum Hall effect and light-induced charge transfer at the interface of graphene/InSe heterostructures.

High-temperature molecular beam epitaxy of hexagonal boron nitride with high active nitrogen fluxes (2018)
Journal Article

Hexagonal boron nitride (hBN) has attracted much attention as a key component in van der Waals heterostructures and as a wide band gap material for deep-ultraviolet devices. We have recently demonstrated plasma-assisted molecular beam epitaxy (PA-MBE... Read More about High-temperature molecular beam epitaxy of hexagonal boron nitride with high active nitrogen fluxes.

Moiré-modulated conductance of hexagonal boron nitride tunnel barriers (2018)
Journal Article

Monolayer hexagonal boron nitride (hBN) tunnel barriers investigated using conductive atomic force microscopy reveal moiré patterns in the spatial maps of their tunnel conductance consistent with the formation of a moiré superlattice between the hB... Read More about Moiré-modulated conductance of hexagonal boron nitride tunnel barriers.

Photoelastic properties of zinc-blende (AlGa)N in the UV: picosecond ultrasonic studies (2018)
Journal Article

Picosecond ultrasonics was used to study the photoelastic properties of zinc-blende (cubic) c-Al?Ga???N with x around 0.5 The velocities for longitudinal sound in the alloys were measured using ultrafast UV pump-probe experiments with (Al... Read More about Photoelastic properties of zinc-blende (AlGa)N in the UV: picosecond ultrasonic studies.

High-temperature molecular beam epitaxy of hexagonal boron nitride layers (2018)
Journal Article

The growth and properties of hexagonal boron nitride (hBN) have recently attracted much attention due to applications in graphene-based monolayer thick 2D-structures and at the same time as a wide band gap material for deep-ultraviolet device (DUV) a... Read More about High-temperature molecular beam epitaxy of hexagonal boron nitride layers.

Lattice-Matched Epitaxial Graphene Grown on Boron Nitride (2017)
Journal Article

Lattice-matched graphene on hexagonal boron nitride is expected to lead to the formation of a band-gap but requires the formation of highly strained material and has not hitherto been realised. We demonstrate that aligned, lattice-matched graphene ca... Read More about Lattice-Matched Epitaxial Graphene Grown on Boron Nitride.

Magnetic field tunable vortex diode made of YBa2Cu3O7?? Josephson junction asymmetrical arrays (2017)
Journal Article

Several Josephson ratchets designed as asymmetrically structured parallel-series arrays of Josephson junctions made of YBa2Cu3O7−δ have been fabricated. From the current-voltage characteristics measured for various values of applied magnetic field, B... Read More about Magnetic field tunable vortex diode made of YBa2Cu3O7?? Josephson junction asymmetrical arrays.

Microwave Generation in Synchronized Semiconductor Superlattices (2017)
Journal Article

We study high-frequency generation in a system of electromagnetically coupled semiconductor superlattices fabricated on the same doped substrate. Applying a bias voltage to a single superlattice generates high-frequency current oscillations. We demon... Read More about Microwave Generation in Synchronized Semiconductor Superlattices.

Deep ultraviolet emission in hexagonal boron nitride grown by high-temperature molecular beam epitaxy (2017)
Journal Article

Hexagonal Boron Nitride Tunnel Barriers Grown on Graphite by High Temperature Molecular Beam Epitaxy (2016)
Journal Article

We demonstrate direct epitaxial growth of high-quality hexagonal boron nitride (hBN) layers on graphite using high-temperature plasma-assisted molecular beam epitaxy. Atomic force microscopy reveals mono- and few-layer island growth, while conducting... Read More about Hexagonal Boron Nitride Tunnel Barriers Grown on Graphite by High Temperature Molecular Beam Epitaxy.

The UK National Quantum Technologies Hub in sensors and metrology (Keynote Paper) (2016)
Journal Article

The UK National Quantum Technology Hub in Sensors and Metrology is one of four flagship initiatives in the UK National of Quantum Technology Program. As part of a 20-year vision it translates laboratory demonstrations to deployable practical devices,... Read More about The UK National Quantum Technologies Hub in sensors and metrology (Keynote Paper).

Strain-Engineered Graphene Grown on Hexagonal Boron Nitride by Molecular Beam Epitaxy (2016)
Journal Article

Graphene grown by high temperature molecular beam epitaxy on hexagonal boron nitride (hBN) forms continuous domains with dimensions of order 20 μm, and exhibits moiré patterns with large periodicities, up to ~30 nm, indicating that the layers are hig... Read More about Strain-Engineered Graphene Grown on Hexagonal Boron Nitride by Molecular Beam Epitaxy.

High temperature MBE of graphene on sapphire and hexagonal boron nitride flakes on sapphire (2016)
Journal Article

The discovery of graphene and its remarkable electronic properties has provided scientists with a revolutionary material system for electronics and optoelectronics. Here, the authors investigate molecular beam epitaxy (MBE) as a growth method for gra... Read More about High temperature MBE of graphene on sapphire and hexagonal boron nitride flakes on sapphire.

Design, fabrication and demonstration of a 1x20 multimode interference splitter for parallel biosensing applications (2016)
Journal Article

This paper presents the experimental achievement of a silicon-on-insulator 1x20 MMI splitter andsimulation evaluations of the TE-like and TM-like mode MMI splitters for parallel biosensing applications. Device fabrication technology and optical chara... Read More about Design, fabrication and demonstration of a 1x20 multimode interference splitter for parallel biosensing applications.

Photonic biosensor chip for early-stage cancer diagnosis (2015)
Conference Proceeding

This paper introduces a generic design of a silicon on silica “lab on a chip” photonic biosensor for medical diagnosis applications, and especially for early-stage cancer diagnosis. The sensitivity of detection of the biosensor developed is at least... Read More about Photonic biosensor chip for early-stage cancer diagnosis.

High Broad-Band Photoresponsivity of Mechanically Formed InSe-Graphene van der Waals Heterostructures (2015)
Journal Article

We exploit the broad-band transparency of graphene and the favorable band line up of graphene with van der Waals InSe crystals to create new functional heterostructures and high-performance photodetectors. The InSe-graphene heterostructure exhibits a... Read More about High Broad-Band Photoresponsivity of Mechanically Formed InSe-Graphene van der Waals Heterostructures.

Ligand-Induced Control of Photoconductive Gain and Doping in a Hybrid Graphene–Quantum Dot Transistor (2015)
Journal Article

In graphene devices decorated with a layer of near-infrared colloidal PbS quantum dots (QDs), the choice of the QD capping ligands and the integrity of the QD layer have a strong influence on the doping, carrier mobility, and photoresponse. By using... Read More about Ligand-Induced Control of Photoconductive Gain and Doping in a Hybrid Graphene–Quantum Dot Transistor.

III-V semiconductor waveguides for photonic functionality at 780 nm (2014)
Journal Article

Photonic integrated circuits based on III-V semiconductor polarization-maintaining waveguides were designed and fabricated for the first time for application in a compact cold-atom gravimeter1,2 at an operational wavelength of 780 nm. Compared with o... Read More about III-V semiconductor waveguides for photonic functionality at 780 nm.

Nonlinear modal coupling in a high-stress doubly-clamped nanomechanical resonator (2012)
Journal Article

We present results from a study of the nonlinear inter-modal coupling between different flexural vibrational modes of a single high-stress, doubly-clamped silicon nitride nanomechanical beam. Using the magnetomotive technique and working at 100 mK we... Read More about Nonlinear modal coupling in a high-stress doubly-clamped nanomechanical resonator.

Scanning capacitance imaging of compressible and incompressible quantum Hall effect edge strips (2012)
Journal Article

We use dynamic scanning capacitance microscopy to image compressible and incompressible strips at the edge of a Hall bar in a two-dimensional electron gas (2DEG) in the quantum Hall effect (QHE) regime. This method gives access to the complex local c... Read More about Scanning capacitance imaging of compressible and incompressible quantum Hall effect edge strips.