Dr TIN CHENG's Outputs (24)

High-temperature Brown-Zak oscillations in graphene/hBN moiré field effect transistor fabricated using molecular beam epitaxy (2024)
Journal Article
Makarovsky, O., Hill, R. J. A., Cheng, T. S., Summerfield, A., Taniguchi, T., Watanabe, K., Mellor, C. J., Patanè, A., Eaves, L., Novikov, S. V., & Beton, P. H. (2024). High-temperature Brown-Zak oscillations in graphene/hBN moiré field effect transistor fabricated using molecular beam epitaxy. Communications Materials, 5, Article 189. https://doi.org/10.1038/s43246-024-00633-x

High-temperature Brown-Zak oscillations in graphene/hBN moiré field effect transistor fabricated using molecular beam epitaxy Graphene placed on hexagonal boron nitride (hBN) has received significant interest due to its excellent electrical performan... Read More about High-temperature Brown-Zak oscillations in graphene/hBN moiré field effect transistor fabricated using molecular beam epitaxy.

Epitaxy of GaSe Coupled to Graphene: From In Situ Band Engineering to Photon Sensing (2024)
Journal Article
Bradford, J., Dewes, B. T., Shiffa, M., Cottam, N. D., Rahman, K., Cheng, T. S., Novikov, S. V., Makarovsky, O., O'Shea, J. N., Beton, P. H., Lara-Avila, S., Harknett, J., Greenaway, M. T., & Patanè, A. (2024). Epitaxy of GaSe Coupled to Graphene: From In Situ Band Engineering to Photon Sensing. Small, 20(40), Article 2404809. https://doi.org/10.1002/smll.202404809

2D semiconductors can drive advances in quantum science and technologies. However, they should be free of any contamination; also, the crystallographic ordering and coupling of adjacent layers and their electronic properties should be well‐controlled... Read More about Epitaxy of GaSe Coupled to Graphene: From In Situ Band Engineering to Photon Sensing.

Thin Ga2O3 Layers by Thermal Oxidation of van der Waals GaSe Nanostructures for Ultraviolet Photon Sensing (2024)
Journal Article
Cottam, N. D., Dewes, B. T., Shiffa, M., Cheng, T. S., Novikov, S. V., Mellor, C. J., Makarovsky, O., Gonzalez, D., Ben, T., & Patanè, A. (2024). Thin Ga2O3 Layers by Thermal Oxidation of van der Waals GaSe Nanostructures for Ultraviolet Photon Sensing. ACS Applied Nano Materials, 7(15), 17553-17560. https://doi.org/10.1021/acsanm.4c02685

Two-dimensional semiconductors (2DSEM) based on van der Waals crystals offer important avenues for nanotechnologies beyond the constraints of Moore's law and traditional semiconductors, such as silicon (Si). However, their application necessitates pr... Read More about Thin Ga2O3 Layers by Thermal Oxidation of van der Waals GaSe Nanostructures for Ultraviolet Photon Sensing.

Spatially-resolved UV-C emission in epitaxial monolayer boron nitride (2024)
Journal Article
Rousseau, A., Plo, J., Plo, J., Valvin, P., Cheng, T. S., Bradford, J., James, T. S. S., Wrigley, J., Mellor, C. J., Beton, P. H., Novikov, S. V., Jacques, V., Gil, B., & Cassabois, G. (2024). Spatially-resolved UV-C emission in epitaxial monolayer boron nitride. 2D Materials, 11(2), Article 025026. https://doi.org/10.1088/2053-1583/ad2f45

We report hyperspectral imaging in the UV-C spectral domain in epitaxial monolayers of hexagonal boron nitride (hBN). Under quasi-resonant laser excitation, the UV-C emission of monolayer hBN consists in resonant Raman scattering and photoluminescenc... Read More about Spatially-resolved UV-C emission in epitaxial monolayer boron nitride.

Cathodoluminescence spectroscopy of monolayer hexagonal boron nitride (2024)
Journal Article
Shima, K., Cheng, T. S., Mellor, C. J., Beton, P. H., Elias, C., Valvin, P., Gil, B., Cassabois, G., Novikov, S. V., & Chichibu, S. F. (2024). Cathodoluminescence spectroscopy of monolayer hexagonal boron nitride. Scientific Reports, 14(1), Article 169. https://doi.org/10.1038/s41598-023-50502-9

Cathodoluminescence (CL) spectroscopy is a suitable technique for studying the luminescent properties of optoelectronic materials because CL has no limitation on the excitable bandgap energy and eliminates ambiguous signals due to simple light scatte... Read More about Cathodoluminescence spectroscopy of monolayer hexagonal boron nitride.

Wafer-Scale Two-Dimensional Semiconductors for Deep UV Sensing (2023)
Journal Article
Shiffa, M., Dewes, B. T., Bradford, J., Cottam, N. D., Cheng, T. S., Mellor, C. J., Makarovskiy, O., Rahman, K., O'Shea, J. N., Beton, P. H., Novikov, S. V., Ben, T., Gonzalez, D., Xie, J., Zhang, L., & Patanè, A. (2024). Wafer-Scale Two-Dimensional Semiconductors for Deep UV Sensing. Small, 20(7), Article 2305865. https://doi.org/10.1002/smll.202305865

2D semiconductors (2SEM) can transform many sectors, from information and communication technology to healthcare. To date, top‐down approaches to their fabrication, such as exfoliation of bulk crystals by “scotch‐tape,” are widely used, but have limi... Read More about Wafer-Scale Two-Dimensional Semiconductors for Deep UV Sensing.

Graphene nanoribbons with hBN passivated edges grown by high-temperature molecular beam epitaxy (2023)
Journal Article
Bradford, J., Cheng, T. S., James, T. S., Khlobystov, A. N., Mellor, C. J., Watanabe, K., Taniguchi, T., Novikov, S. V., & Beton, P. H. (2023). Graphene nanoribbons with hBN passivated edges grown by high-temperature molecular beam epitaxy. 2D Materials, 10(3), Article 035035. https://doi.org/10.1088/2053-1583/acdefc

Integration of graphene and hexagonal boron nitride (hBN) in lateral heterostructures has provided a route to broadly engineer the material properties by quantum confinement of electrons or introduction of novel electronic and magnetic states at the... Read More about Graphene nanoribbons with hBN passivated edges grown by high-temperature molecular beam epitaxy.

Exciton and Phonon Radiative Linewidths in Monolayer Boron Nitride (2022)
Journal Article
Cassabois, G., Fugallo, G., Elias, C., Valvin, P., Rousseau, A., Gil, B., Summerfield, A., Mellor, C. J., Cheng, T. S., Eaves, L., Foxon, C., Beton, P., Lazzeri, M., Segura, A., & Novikov, S. (2022). Exciton and Phonon Radiative Linewidths in Monolayer Boron Nitride. Physical Review X, 12(1), Article 011057. https://doi.org/10.1103/physrevx.12.011057

The light-matter interaction in bulk semiconductors is in the strong coupling regime with hybrid eigenstates, the so-called exciton-polaritons and phonon-polaritons. In two-dimensional (2D) systems, the translational invariance is broken in the direc... Read More about Exciton and Phonon Radiative Linewidths in Monolayer Boron Nitride.

Exciton and Phonon Radiative Linewidths in Monolayer Boron Nitride (2022)
Journal Article
Cassabois, G., Fugallo, G., Elias, C., Valvin, P., Rousseau, A., Gil, B., Summerfield, A., Mellor, C., Cheng, T., Eaves, L., Foxon, C., Beton, P., Lazzeri, M., Segura, A., & Novikov, S. (2022). Exciton and Phonon Radiative Linewidths in Monolayer Boron Nitride. Physical Review X, 12(1), Article 011057. https://doi.org/10.1103/PhysRevX.12.011057

The light-matter interaction in bulk semiconductors is in the strong-coupling regime with hybrid eigenstates, the so-called exciton polaritons and phonon polaritons. In two-dimensional (2D) systems, the translational invariance is broken in the direc... Read More about Exciton and Phonon Radiative Linewidths in Monolayer Boron Nitride.

Band gap measurements of monolayer h-BN and insights into carbon-related point defects (2021)
Journal Article
Román, R. J. P., Costa, F. J. R., Zobelli, A., Elias, C., Valvin, P., Cassabois, G., GIL, B., Summerfield, A., Cheng, T. S., Mellor, C. J., Beton, P. H., Novikov, S. V., & Zagonel, L. F. (2021). Band gap measurements of monolayer h-BN and insights into carbon-related point defects. 2D Materials, 8(4), Article 044001. https://doi.org/10.1088/2053-1583/ac0d9c

Being a flexible wide band gap semiconductor, hexagonal boron nitride (h-BN) has great potential for technological applications like efficient deep ultraviolet light sources, building block for two-dimensional heterostructures and room temperature si... Read More about Band gap measurements of monolayer h-BN and insights into carbon-related point defects.

Epitaxy of boron nitride monolayers for graphene-based lateral heterostructures (2021)
Journal Article
Wrigley, J., Bradford, J., James, T., Cheng, T. S., Thomas, J., Mellor, C. J., Khlobystov, A. N., Eaves, L., Foxon, C. T., Novikov, S. V., & Beton, P. H. (2021). Epitaxy of boron nitride monolayers for graphene-based lateral heterostructures. 2D Materials, 8(3), 1-10. https://doi.org/10.1088/2053-1583/abea66

Monolayers of hexagonal boron nitride (hBN) are grown on graphite substrates using high-temperature molecular beam epitaxy (HT-MBE). The hBN monolayers are observed to grow predominantly from step edges on the graphite surface and exhibit a strong de... Read More about Epitaxy of boron nitride monolayers for graphene-based lateral heterostructures.

Identifying carbon as the source of visible single-photon emission from hexagonal boron nitride (2020)
Journal Article
Mendelson, N., Chugh, D., Reimers, J. R., Cheng, T. S., Gottscholl, A., Long, H., Mellor, C. J., Zettl, A., Dyakonov, V., Beton, P. H., Novikov, S. V., Jagadish, C., Tan, H. H., Ford, M. J., Toth, M., Bradac, C., & Aharonovich, I. (2021). Identifying carbon as the source of visible single-photon emission from hexagonal boron nitride. Nature Materials, 20(3), 321-328. https://doi.org/10.1038/s41563-020-00850-y

Single-photon emitters (SPEs) in hexagonal boron nitride (hBN) have garnered increasing attention over the last few years due to their superior optical properties. However, despite the vast range of experimental results and theoretical calculations,... Read More about Identifying carbon as the source of visible single-photon emission from hexagonal boron nitride.

Step-Flow Growth of Graphene-Boron Nitride Lateral Heterostructures by Molecular Beam Epitaxy (2020)
Journal Article
Thomas, J., Bradford, J., Cheng, T. S., Summerfield, A., Wrigley, J., Mellor, C. J., Khlobystov, A., Foxon, C. T., Eaves, L., Novikov, S. V., & Beton, P. H. (2020). Step-Flow Growth of Graphene-Boron Nitride Lateral Heterostructures by Molecular Beam Epitaxy. 2D Materials, 7(3), Article 035014. https://doi.org/10.1088/2053-1583/ab89e7

Integration of graphene and hexagonal boron nitride (hBN) into lateral heterostructures has drawn focus due to the ability to broadly engineer the material properties. Hybrid monolayers with tuneable bandgaps have been reported, while the interface i... Read More about Step-Flow Growth of Graphene-Boron Nitride Lateral Heterostructures by Molecular Beam Epitaxy.

Optimizing automatic morphological classification of galaxies with machine learning and deep learning using Dark Energy Survey imaging (2020)
Journal Article
Cheng, T.-Y., Conselice, C. J., Aragón-Salamanca, A., Li, N., Bluck, A. F., Hartley, W. G., Annis, J., Brooks, D., Doel, P., García-Bellido, J., James, D. J., Kuehn, K., Kuropatkin, N., Smith, M., Sobreira, F., & Tarle, G. (2020). Optimizing automatic morphological classification of galaxies with machine learning and deep learning using Dark Energy Survey imaging. Monthly Notices of the Royal Astronomical Society, 493(3), 4209-4228. https://doi.org/10.1093/mnras/staa501

There are several supervised machine learning methods used for the application of automated morphological classification of galaxies; however, there has not yet been a clear comparison of these different methods using imaging data, or a investigation... Read More about Optimizing automatic morphological classification of galaxies with machine learning and deep learning using Dark Energy Survey imaging.

Direct band-gap crossover in epitaxial monolayer boron nitride (2019)
Journal Article
Elias, C., Valvin, P., Pelini, T., Summerfield, A., Mellor, C., Cheng, T., Eaves, L., Foxon, C., Beton, P., Novikov, S., Gil, B., & Cassabois, G. (2019). Direct band-gap crossover in epitaxial monolayer boron nitride. Nature Communications, 10, Article 2639. https://doi.org/10.1038/s41467-019-10610-5

Hexagonal boron nitride is a large band-gap insulating material which complements the electronic and optical properties of graphene and the transition metal dichalcogenides. However, the intrinsic optical properties of monolayer boron nitride remain... Read More about Direct band-gap crossover in epitaxial monolayer boron nitride.

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., Beton, P. H., & Novikov, S. V. (2018). High-temperature molecular beam epitaxy of hexagonal boron nitride with high active nitrogen fluxes. Materials, 11(7), https://doi.org/10.3390/ma11071119

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
Summerfield, A., Kozikov, A., Cheng, T. S., Davies, A., Cho, Y.-J., Khlobystov, A. N., Mellor, C. J., Foxon, C. T., Watanabe, K., Taniguchi, T., Eaves, L., Novoselov, K. S., Novikov, S. V., & Beton, P. H. (in press). Moiré-modulated conductance of hexagonal boron nitride tunnel barriers. Nano Letters, https://doi.org/10.1021/acs.nanolett.8b01223

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.

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., Foxon, C. T., Beton, P. H., & 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., Stapleton, E., Wrigley, J., Goodey, N. L., Mellor, C. J., Khlobystov, A. N., Watanabe, K., Taniguchi, T., Foxon, C., Eaves, L., Novikov, S. 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.

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., Mellor, C., Taniguchi, T., Watanabe, K., Foxon, C., Eaves, L., Beton, P. H., & 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.