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High-temperature molecular beam epitaxy of hexagonal boron nitride layers (2018)
Journal Article
Cheng, T. S., Summerfield, A., Mellor, C. J., Davies, A., Khlobystov, A. N., Eaves, L., …Novikov, S. V. (in press). High-temperature molecular beam epitaxy of hexagonal boron nitride layers. Journal of Vacuum Science and Technology B, 36(2), Article 02D103-1. https://doi.org/10.1116/1.5011280

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
Davies, A., Albar, J., Summerfield, A., Thomas, J. C., Cheng, T. S., Korolkov, V. V., …Beton, P. H. (2018). Lattice-Matched Epitaxial Graphene Grown on Boron Nitride. Nano Letters, 18(1), 498-504. https://doi.org/10.1021/acs.nanolett.7b04453

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.

Giant Quantum Hall Plateau in Graphene Coupled to an InSe van der Waals Crystal (2017)
Journal Article
Kudrynskyi, Z. R., Bhuiyan, M. A., Makarovsky, O., Greener, J. D., Vdovin, E. E., Kovalyuk, Z. D., …Patanè, A. (2017). Giant Quantum Hall Plateau in Graphene Coupled to an InSe van der Waals Crystal. Physical Review Letters, 119(15), Article 157701. https://doi.org/10.1103/PhysRevLett.119.157701

© 2017 authors. Published by the American Physical Society. We report on a "giant" quantum Hall effect plateau in a graphene-based field-effect transistor where graphene is capped by a layer of the van der Waals crystal InSe. The giant quantum Hall e... Read More about Giant Quantum Hall Plateau in Graphene Coupled to an InSe van der Waals Crystal.

An atomic carbon source for high temperature molecular beam epitaxy of graphene (2017)
Journal Article
Albar, J., Summerfield, A., Cheng, T. S., Davies, A., Smith, E., Khlobystov, A. N., …Novikov, S. V. (in press). An atomic carbon source for high temperature molecular beam epitaxy of graphene. Scientific Reports, 7(1), Article 6598. https://doi.org/10.1038/s41598-017-07021-1

We report the use of a novel atomic carbon source for the molecular beam epitaxy (MBE) of graphene layers on hBN flakes and on sapphire wafers at substrate growth temperatures of ~1400 °C. The source produces a flux of predominantly atomic carbon, wh... Read More about An atomic carbon source for high temperature molecular beam epitaxy of graphene.

High-temperature quantum oscillations caused by recurring Bloch states in graphene superlattices (2017)
Journal Article
Krishna Kumar, R. K., Chen, X., Auton, G., Mishchenko, A., Bandurin, D. A., Morozov, S., …Geim, A. (2017). High-temperature quantum oscillations caused by recurring Bloch states in graphene superlattices. Science, 357(6347), 181-184. https://doi.org/10.1126/science.aal3357

Cyclotron motion of charge carriers in metals and semiconductors leads to Landau quantization and magneto-oscillatory behavior in their properties. Cryogenic temperatures are usually required to observe these oscillations. We show that graphene super... Read More about High-temperature quantum oscillations caused by recurring Bloch states in graphene superlattices.

Enhancing optoelectronic properties of SiC-grown graphene by a surface layer of colloidal quantum dots (2017)
Journal Article
Makarovsky, O., Turyanska, L., Mori, N., Greenaway, M., Eaves, L., Patanè, A., …Yakimova, R. (in press). Enhancing optoelectronic properties of SiC-grown graphene by a surface layer of colloidal quantum dots. 2D Materials, 4(3), https://doi.org/10.1088/2053-1583/aa76bb

We report a simultaneous increase of carrier concentration, mobility and photoresponsivity when SiC-grown graphene is decorated with a surface layer of colloidal PbS quantum dots, which act as electron donors. The charge on the ionised dots is spatia... Read More about Enhancing optoelectronic properties of SiC-grown graphene by a surface layer of colloidal quantum dots.

Fast, multicolor photodetection with graphene-contacted p-GaSe/n-InSe van der Waals heterostructures (2017)
Journal Article
Yan, F., Zhao, L., Patanè, A., Hu, P., Wei, X., Luo, W., …Wang, K. (2017). Fast, multicolor photodetection with graphene-contacted p-GaSe/n-InSe van der Waals heterostructures. Nanotechnology, 28(27), Article 27LT01. https://doi.org/10.1088/1361-6528/aa749e

The integration of different two-dimensional materials within a multilayer van der Waals (vdW) heterostructure offers a promising technology for high performance opto-electronic devices such as photodetectors and light sources. Here we report on the... Read More about Fast, multicolor photodetection with graphene-contacted p-GaSe/n-InSe van der Waals heterostructures.

Engineering p-n junctions and bandgap tuning of InSe nanolayers by controlled oxidation (2017)
Journal Article
Balakrishnan, N., Kudrynskyi, Z. R., Smith, E. F., Fay, M. W., Makarovsky, O., Kovalyuk, Z. D., …Patanè, A. (2017). Engineering p-n junctions and bandgap tuning of InSe nanolayers by controlled oxidation. 2D Materials, 4(2), Article 025043. https://doi.org/10.1088/2053-1583/aa61e0

Exploitation of two-dimensional (2D) van der Waals (vdW) crystals can be hindered by the deterioration of the crystal surface over time due to oxidation. On the other hand, the existence of a stable oxide at room temperature can offer prospects for s... Read More about Engineering p-n junctions and bandgap tuning of InSe nanolayers by controlled oxidation.

Mobility enhancement of CVD graphene by spatially correlated charges (2017)
Journal Article
Turyanska, L., Makarovsky, O., Eaves, L., Patanè, A., & Mori, N. (2017). Mobility enhancement of CVD graphene by spatially correlated charges. 2D Materials, 4(2), Article 025026. https://doi.org/10.1088/2053-1583/aa55b4

The manuscript presents a strategy for enhancing the carrier mobility of single layer CVD graphene (CVD SLG) based on spatially correlated charges. Our Monte Carlo simulations, numerical modeling and the experimental results confirm that spatial corr... Read More about Mobility enhancement of CVD graphene by spatially correlated charges.

The direct-to-indirect band gap crossover in two-dimensional van der Waals Indium Selenide crystals (2016)
Journal Article
Mudd, G., Molas, M., Chen, X., Zólyomi, V., Nogajewski, K., Kudrynskyi, Z. R., …Patanè, A. (2016). The direct-to-indirect band gap crossover in two-dimensional van der Waals Indium Selenide crystals. Scientific Reports, 6(1), Article 39619. https://doi.org/10.1038/srep39619

The electronic band structure of van der Waals (vdW) layered crystals has properties that depend on the composition, thickness and stacking of the component layers. Here we use density functional theory and high field magneto-optics to investigate th... Read More about The direct-to-indirect band gap crossover in two-dimensional van der Waals Indium Selenide crystals.

High electron mobility, quantum Hall effect and anomalous optical response in atomically thin InSe (2016)
Journal Article
Bandurin, D. A., Tyurnina, A. V., Yu, G. L., Mishchenko, A., Zólyomi, V., Morozov, S. V., …Cao, Y. (2017). High electron mobility, quantum Hall effect and anomalous optical response in atomically thin InSe. Nature Nanotechnology, 12(3), 223-227. https://doi.org/10.1038/nnano.2016.242

© 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved. A decade of intense research on two-dimensional (2D) atomic crystals has revealed that their properties can differ greatly from those of the parent compound. These dif... Read More about High electron mobility, quantum Hall effect and anomalous optical response in atomically thin InSe.

Hexagonal Boron Nitride Tunnel Barriers Grown on Graphite by High Temperature Molecular Beam Epitaxy (2016)
Journal Article
Cho, Y., Summerfield, A., Davies, A., Cheng, T. S., Smith, E. F., Mellor, C. J., …Novikov, S. V. (2016). Hexagonal Boron Nitride Tunnel Barriers Grown on Graphite by High Temperature Molecular Beam Epitaxy. Scientific Reports, 6(1), Article 34474. https://doi.org/10.1038/srep34474

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.

Resonant Zener tunnelling via zero-dimensional states in a narrow gap diode (2016)
Journal Article
Di Poala, D. M., Kesaria, M., Makarovsky, O., Velichko, A., Eaves, L., Mori, N., …Patanè, A. (in press). Resonant Zener tunnelling via zero-dimensional states in a narrow gap diode. Scientific Reports, 6, Article e32039. https://doi.org/10.1038/srep32039

Interband tunnelling of carriers through a forbidden energy gap, known as Zener tunnelling, is a phenomenon of fundamental and technological interest. Its experimental observation in the Esaki p-n semiconductor diode has led to the first demonstratio... Read More about Resonant Zener tunnelling via zero-dimensional states in a narrow gap diode.

Tuning the valley and chiral quantum state of Dirac electrons in van der Waals heterostructures (2016)
Journal Article
Wallbank, J. . R., Ghazaryan, D., Misra, A., Cao, Y., Tu, J. . S., Piot, B. A., …Mishchenko, A. (2016). Tuning the valley and chiral quantum state of Dirac electrons in van der Waals heterostructures. Science, 353(6299), 575-579. https://doi.org/10.1126/science.aaf4621

Chirality is a fundamental property of electrons with the relativistic spectrum found in graphene and topological insulators. It plays a crucial role in relativistic phenomena, such as Klein tunneling, but it is difficult to visualize directly. Here... Read More about Tuning the valley and chiral quantum state of Dirac electrons in van der Waals heterostructures.

Quantum confinement and photoresponsivity of ?-In2Se3 nanosheets grown by physical vapour transport (2016)
Journal Article
Balakrishnan, N., Staddon, C. R., Smith, E. F., Stec, J., Gay, D., Mudd, G. W., …Beton, P. H. (in press). Quantum confinement and photoresponsivity of β-In2Se3 nanosheets grown by physical vapour transport. 2D Materials, 3(2), 1-8. https://doi.org/10.1088/2053-1583/3/2/025030

We demonstrate that β-In2Se3 layers with thickness ranging from 2.8 – 100 nm can be grown on SiO2/Si, mica and graphite using a physical vapour transport method. The β-In2Se3 layers are chemically stable at room temperature and exhibit a blue-shift o... Read More about Quantum confinement and photoresponsivity of ?-In2Se3 nanosheets grown by physical vapour transport.

Phonon-Assisted Resonant Tunneling of Electrons in Graphene–Boron Nitride Transistors (2016)
Journal Article
Vdovin, E. E., Mishchenko, A., Greenaway, M., Zhu, M., Ghazaryan, D., Misra, A., …Eaves, L. (2016). Phonon-Assisted Resonant Tunneling of Electrons in Graphene–Boron Nitride Transistors. Physical Review Letters, 116(18), Article 186603. https://doi.org/10.1103/PhysRevLett.116.186603

We observe a series of sharp resonant features in the differential conductance of graphene-hexagonal boron nitride-graphene tunnel transistors over a wide range of bias voltages between 10 and 200 mV. We attribute them to electron tunneling assisted... Read More about Phonon-Assisted Resonant Tunneling of Electrons in Graphene–Boron Nitride Transistors.

Strain-Engineered Graphene Grown on Hexagonal Boron Nitride by Molecular Beam Epitaxy (2016)
Journal Article
Summerfield, A., Davies, A., Cheng, T. S., Korolkov, V. V., Cho, Y., Mellor, C. J., …Beton, P. H. (2016). Strain-Engineered Graphene Grown on Hexagonal Boron Nitride by Molecular Beam Epitaxy. Scientific Reports, 6(1), Article 22440. https://doi.org/10.1038/srep22440

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
Cheng, T. S., Davies, A., Summerfield, A., Cho, Y., Cebula, I., Hill, R. J., …Novikov, S. V. (2016). High temperature MBE of graphene on sapphire and hexagonal boron nitride flakes on sapphire. Journal of Vacuum Science and Technology B, 34(2), 02L101. https://doi.org/10.1116/1.4938157

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.

Resonant tunnelling between the chiral Landau states of twisted graphene lattices (2015)
Journal Article
Greenaway, M., Vdovin, E. E., Mishchenko, A., Makarovsky, O., Patanè, A., Wallbank, J., …Eaves, L. (2015). Resonant tunnelling between the chiral Landau states of twisted graphene lattices. Nature Physics, 11(12), 1057-1062. https://doi.org/10.1038/nphys3507

A class of multilayered functional materials has recently emerged in which the component atomic layers are held together by weak van der Waals forces that preserve the structural integrity and physical properties of each layer. An exemplar of such a... Read More about Resonant tunnelling between the chiral Landau states of twisted graphene lattices.