Research Repository

See what's under the surface


Adsorption of hexacontane on hexagonal boron nitride (2018)
Journal Article
Albar, J. D., Korolkov, V. V., Baldoni, M., Watanabe, K., Taniguchi, T., Besley, E., & Beton, P. H. (2018). Adsorption of hexacontane on hexagonal boron nitride. Journal of Physical Chemistry C, 122, 27575-27581. doi:10.1021/acs.jpcc.8b10167

We have investigated the adsorption of hexacontane (C60 H122) on hexagonal boron nitride (hBN) using atomic force microscopy (AFM). The molecules can be deposited either by sublimation or from solution and form lamellar rows with dimensions of the or... Read More

The growth and fluorescence of phthalocyanine monolayers, thin films and multilayers on hexagonal boron nitride (2018)
Journal Article
Alkhamisi, M., Korolkov, V. V., Nizovtsev, A. S., Kerfoot, J., Taniguchi, T., Watanabe, K., …Beton, P. H. (2018). The growth and fluorescence of phthalocyanine monolayers, thin films and multilayers on hexagonal boron nitride. Chemical Communications, doi:10.1039/C8CC06304D. ISSN 1359-7345

Free-base phthalocyanine forms distinct interfacial phases and thin films on hexagonal boron nitride including a monolayer arrangement as determined using high resolution atomic force microscopy. The phases reveal significant differences in photolumi... Read More

Coherent acoustic phonons in van der Waals nanolayers and heterostructures (2018)
Journal Article
Greener, J. D., Akimov, A. V., Gusev, V., Kudrynskyi, Z., Beton, P. H., Kovalyuk, Z. D., …Patanè, A. (2018). Coherent acoustic phonons in van der Waals nanolayers and heterostructures. Physical Review B, 98(7), doi:10.1103/PhysRevB.98.075408. ISSN 2469-9950

Terahertz (THz) and sub-THz coherent acoustic phonons have been successfully used as probes of various quantum systems. Since their wavelength is in the nanometer range, they can probe nanostructures buried below a surface with nanometer resolution a... Read More

High-temperature molecular beam epitaxy of hexagonal boron nitride with high active nitrogen fluxes (2018)
Journal Article
Cheng, T. S., Summerfield, A., Mellor, C. J., Khlobystov, A. N., Eaves, L., Foxon, C. T., …Novikov, S. V. (2018). High-temperature molecular beam epitaxy of hexagonal boron nitride with high active nitrogen fluxes. Materials, 11(7), doi:10.3390/ma11071119. ISSN 1996-1944

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

Moiré-modulated conductance of hexagonal boron nitride tunnel barriers (2018)
Journal Article
Summerfield, A., Kozikov, A., Cheng, T. S., Davies, A., Cho, Y., Khlobystov, A. N., …Beton, P. H. (in press). Moiré-modulated conductance of hexagonal boron nitride tunnel barriers. Nano Letters, doi:10.1021/acs.nanolett.8b01223. ISSN 1530-6984

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

Epitaxial growth of γ-InSe and α, β, and γ-In2Se3 on ε-GaSe (2018)
Journal Article
Balakrishnan, N., Steer, E. D., Smith, E. F., Kudrynskyi, Z. R., Kovalyuk, Z. D., Eaves, L., …Beton, P. H. (2018). Epitaxial growth of γ-InSe and α, β, and γ-In2Se3 on ε-GaSe. 2D Materials, 5(3), doi:10.1088/2053-1583/aac479. ISSN 2053-1583

We demonstrate that γ-InSe and the α, β and γ phases of In2Se3 can be grown epitaxially on ε-GaSe substrates using a physical vapour transport method. By exploiting the temperature gradient within the tube furnace, we can grow selectively different p... Read More

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), doi:10.1116/1.5011280. ISSN 2166-2746

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

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), doi:10.1021/acs.nanolett.7b04453. ISSN 1530-6984

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

Supramolecular networks stabilise and functionalise black phosphorus (2017)
Journal Article
Korolkov, V. V., Timokhin, I. G., Haubrichs, R., Smith, E. F., Yang, L., Yang, S., …Beton, P. H. (in press). Supramolecular networks stabilise and functionalise black phosphorus. Nature Communications, 8, doi:10.1038/s41467-017-01797-6. ISSN 2041-1723

The limited stability of the surface of black phosphorus (BP) under atmospheric conditions is a significant constraint on the exploitation of this layered material and its few layer analogue, phosphorene, as an optoelectronic material. Here we show t... Read More

A 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). A giant quantum Hall plateau in graphene coupled to an InSe van der Waals crystal. Physical Review Letters, 119(15), doi:10.1103/PhysRevLett.119.157701. ISSN 0031-9007

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 effect plateau arises from the close alignment of the condu... Read More

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), doi:10.1038/s41598-017-07021-1. ISSN 2045-2322

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

Supramolecular heterostructures formed by sequential epitaxial deposition of two-dimensional hydrogen-bonded arrays (2017)
Journal Article
Korolkov, V. V., Baldoni, M., Watanabe, K., Taniguchi, T., Besley, E., & Beton, P. H. (in press). Supramolecular heterostructures formed by sequential epitaxial deposition of two-dimensional hydrogen-bonded arrays. Nature Chemistry, 9, doi:10.1038/nchem.2824. ISSN 1755-4330

Two-dimensional (2D) supramolecular arrays provide a route to the spatial control of the chemical functionality of a surface, but their deposition is in almost all cases limited to a monolayer termination. Here we investigated the sequential depositi... Read More

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), doi:10.1088/2053-1583/aa61e0. ISSN 2053-1583

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

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. (in press). Hexagonal boron nitride tunnel barriers grown on graphite by high temperature molecular beam epitaxy. Scientific Reports, 6, doi:10.1038/srep34474. ISSN 2045-2322

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

Naphthalocyanine thin films and field effect transistors (2016)
Journal Article
Esmail, A. M., Staddon, C. R., & Beton, P. H. (2016). Naphthalocyanine thin films and field effect transistors. Journal of Physical Chemistry C, 120(28), doi:10.1021/acs.jpcc.6b06134. ISSN 1932-7447

Naphthalocyanine (Nc) thin films have been grown by sublimation on SiO2. We have used atomic force microscopy and X-ray diffraction to show that the films are disordered for room temperature deposition, but show a highly crystalline needlelike morpho... Read More

Organisation and ordering of 1D porphyrin polymers synthesised by on-surface Glaser coupling (2016)
Journal Article
Saywell, A., Browning, A. S., Rahe, P., Anderson, H. L., & Beton, P. H. (in press). Organisation and ordering of 1D porphyrin polymers synthesised by on-surface Glaser coupling. Chemical Communications, 52(68), doi:10.1039/C6CC03758E. ISSN 1359-7345

One-dimensional polymer chains consisting of π-conjugated porphyrin units are formed via Glaser coupling on a Ag(111) surface. Scanning probe microscopy reveals the covalent structure of the products and their ordering. The conformational flexibility... Read More

Quantum confinement and photoresponsivity of β-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). doi:10.1088/2053-1583/3/2/025030. ISSN 2053-1583

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