All Outputs (42)

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(1), Article 189. https://doi.org/10.1038/s43246-024-00633-x

Graphene placed on hexagonal boron nitride (hBN) has received significant interest due to its excellent electrical performance and physics phenomena, such as superlattice Dirac points. Direct molecular beam epitaxy growth of graphene on hBN offers an... Read More about High-temperature Brown-Zak oscillations in graphene/hBN moiré field effect transistor fabricated using molecular beam epitaxy.

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.

Optical Monitoring of In Situ Iron Loading into Single, Native Ferritin Proteins (2023)
Journal Article
Yousefi, A., Ying, C., Parmenter, C. D. J., Assadipapari, M., Sanderson, G., Zheng, Z., Xu, L., Zargarbashi, S., Hickman, G. J., Cousins, R. B., Mellor, C. J., Mayer, M., & Rahmani, M. (2023). Optical Monitoring of In Situ Iron Loading into Single, Native Ferritin Proteins. Nano Letters, 23(8), 3251-3258. https://doi.org/10.1021/acs.nanolett.3c00042

Ferritin is a protein that stores and releases iron to prevent diseases associated with iron dysregulation in plants, animals, and bacteria. The conversion between iron-loaded holo-ferritin and empty apo-ferritin is an important process for iron regu... Read More about Optical Monitoring of In Situ Iron Loading into Single, Native Ferritin Proteins.

Diffractive metasurface light-shaping from fiber endoscope probes for increased depth of field (2023)
Presentation / Conference Contribution
He, F., Gordon, G., Fuentes-Dominguez, R., Cousins, R., Mellor, C. J., Barton, J. . K., & Gordon, G. S. . D. Diffractive metasurface light-shaping from fiber endoscope probes for increased depth of field. Presented at Endoscopic Microscopy XVIII, San Francisco, USA

In applications such as optical coherence tomography, there is a need both to achieve large depth of field by light shaping and to maintain ultracompact form factors. Flat metasurfaces on optical fibers can achieve such requirements, with designs suc... Read More about Diffractive metasurface light-shaping from fiber endoscope probes for increased depth of field.

The influence of magnetic vortices motion on the inverse ac Josephson effect in asymmetric arrays (2022)
Journal Article
Chesca, B., Gaifullin, M., John, D., Cox, J., Savel'ev, S., & Mellor, C. (2022). The influence of magnetic vortices motion on the inverse ac Josephson effect in asymmetric arrays. Applied Physics Letters, 121(16), Article 162601. https://doi.org/10.1063/5.0121779

We report on the influence a preferential magnetic vortices motion has on the magnitude of the inverse ac Josephson effect (the appearance of dc current Shapiro steps) and the coherent operation of asymmetrical parallel arrays of YBa2Cu3O7−δ Josephso... Read More about The influence of magnetic vortices motion on the inverse ac Josephson effect in asymmetric arrays.

Reactive laser annealing of indium tin oxide: implications to crystal structure, defect composition, and plasma energy (2022)
Journal Article
Hillier, J., Patsalas, P., Karfardis, D., Cranton, W., Nabok, A., Mellor, C. J., Koutsogeorgis, D., & Kalfagiannis, N. (2022). Reactive laser annealing of indium tin oxide: implications to crystal structure, defect composition, and plasma energy. Optical Materials Express, 12(11), 4310-4327. https://doi.org/10.1364/ome.464918

The mechanisms governing the modification of the optoelectronic properties of low carrier concentration indium tin oxide (ITO) during reactive laser annealing (ReLaA) are investigated. ReLA combines the advantages of reactive ambient thermal annealin... Read More about Reactive laser annealing of indium tin oxide: implications to crystal structure, defect composition, and plasma energy.

Photo-engineered optoelectronic properties of indium tin oxide via reactive laser annealing (2022)
Journal Article
Hillier, J. A., Patsalas, P., Karfaridis, D., Camelio, S., Cranton, W., Nabok, A. V., Mellor, C. J., Koutsogeorgis, D. C., & Kalfagiannis, N. (2022). Photo-engineered optoelectronic properties of indium tin oxide via reactive laser annealing. Scientific Reports, 12, Article 14986. https://doi.org/10.1038/s41598-022-18883-5

Transparent conductive oxides are appealing materials for optoelectronic and plasmonic applications as, amongst other advantages, their properties can be modulated by engineering their defects. Optimisation of this adjustment is, however, a complex d... Read More about Photo-engineered optoelectronic properties of indium tin oxide via reactive laser annealing.

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.

Spectrally tailored hyperpixel filter arrays for efficient imaging of chemical compositions (2022)
Presentation / Conference Contribution
Taylor-Williams, M., Cousins, R., Williams, C., Bohndiek, S. E., Mellor, C. J., & Gordon, G. S. D. Spectrally tailored hyperpixel filter arrays for efficient imaging of chemical compositions. Presented at SPIE Photonics West 2022, San Francisco, United States

We present a method for designing and fabricating 'HyperPixels': pixel filter arrays with custom spectral transmission properties that enable efficient imaging of specific chromophores or fluorophores. Multispectral imaging typically targets particul... Read More about Spectrally tailored hyperpixel filter arrays for efficient imaging of chemical compositions.

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.

Transfering ultra-Thin metallic metasurfaces to fibre endoscope probes for advanced imaging (2022)
Presentation / Conference Contribution
Fuentes-Dominguez, R., He, F., Cousins, R., Mellor, C. J., & Gordon, G. S. D. (2022, January). Transfering ultra-Thin metallic metasurfaces to fibre endoscope probes for advanced imaging. Presented at SPIE Photonics West 2022, San Francisco, California, USA

In this paper we present a method to transfer ultra-Thin polymer-encapsulated metallic metasurfaces onto optical fibers to enable ultra-Thin imaging devices. The metasurface is first produced by conventional e-beam lithography on a silicon substrate... Read More about Transfering ultra-Thin metallic metasurfaces to fibre endoscope probes for advanced imaging.

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.

Near infrared integrated photonic switches for portable quantum sensors (2021)
Journal Article
Saleeb-Mousa, B., Moss, J. L., Maclean, J. O., Campion, R. P., & Mellor, C. J. (2021). Near infrared integrated photonic switches for portable quantum sensors. Journal of Physics: Conference Series, 1919(1), 1-8. https://doi.org/10.1088/1742-6596/1919/1/012007

A novel integrated semiconductor photonic switch, based on carrier-induced refractive index changes, has been designed and fabricated for use at near infrared wavelengths (890-920 nm, 750-780 nm and 745-775 nm). These switches are intended for use in... Read More about Near infrared integrated photonic switches for portable quantum sensors.

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.

Magnetic flux quantum periodicity of the frequency of the on-chip detectable electromagnetic radiation from superconducting flux-flow-oscillators (2020)
Journal Article
Chesca, B., John, D., Gaifullin, M., Cox, J., Murphy, A., Savel'ev, S., & Mellor, C. J. (2020). Magnetic flux quantum periodicity of the frequency of the on-chip detectable electromagnetic radiation from superconducting flux-flow-oscillators. Applied Physics Letters, 117(14), Article 142601. https://doi.org/10.1063/5.0021970

Superconducting flux-flow-oscillators (FFOs) based on unidirectional flow of magnetic vortices in a single-long Josephson junction (JJ) and operating at 4.2 K are key elements of sub-terahertz integrated-receivers used in radio-astronomy and atmosphe... Read More about Magnetic flux quantum periodicity of the frequency of the on-chip detectable electromagnetic radiation from superconducting flux-flow-oscillators.