Duncan Mowbray | University of the Basque Country, Euskal Herriko Unibertsitatea (original) (raw)
Papers by Duncan Mowbray
A thorough understanding of the electronic structure is a necessary first step for the design of ... more A thorough understanding of the electronic structure is a necessary first step for the design of nanoelectronics, chemical/bio-sensors, electrocatalysts, and nanoplasmonics using graphene. As such, theoretical spectroscopic tech-niques to describe collective excitations of graphene are of fundamental importance. Starting from density functional theory (DFT), linear response time dependent DFT in frequency-reciprocal space within the random phase approxima-tion (TDDFT-RPA) is used to describe the loss function −={ε−1(q, ω)} for isolated graphene. To ensure any spurious interactions between layers are removed, both a radial cutoff of the Coulomb kernel, and extra vacuum directly at the TDDFT-RPA level are employed. A combination of both methods is found to provide a correct description of the electron energy loss spectra of isolated graphene, at a significant reduction in computational cost compared to standard methods. 1 Introduction In the last ten years, graphene [1,2, 3,4,5,6,7,8,...
∗Nano-Bio Spectroscopy Group and ETSF Scientific Development Centre, Depto. Fı́sica de Materiales... more ∗Nano-Bio Spectroscopy Group and ETSF Scientific Development Centre, Depto. Fı́sica de Materiales, Universidad del Paı́s Vasco and DIPC, Avenida de Tolosa 72, E-20018 San Sebastián, Spain; Phone:+34 943 01 8288 Fax:+34 943 01 8390 E-mail: duncan.mowbray@gmail.com †Nano-Bio Spectroscopy Group and ETSF Scientific Development Centre, Depto. Fı́sica de Materiales, Universidad del Paı́s Vasco, Centro de Fı́sica de Materiales CSIC-UPV/EHUMPC and DIPC, Av. Tolosa 72, E-20018 San Sebastián, Spain; Center for Atomic-scale Materials Design, Department of Physics, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark; Phone:+45 4525 3209 Fax:+45 4593 2399 E-mail: jumagala@fysik.dtu.dk ‡Nano-Bio Spectroscopy Group and ETSF Scientific Development Centre, Depto. Fı́sica de Materiales, Universidad del Paı́s Vasco and DIPC, Avenida de Tolosa 72, E-20018 San Sebastián, Spain; E-mail: ilarrazaarocena@gmail.com §Nano-Bio Spectroscopy Group and ETSF Scientific Development Centre, Depto. Fı́sica...
The Journal of Chemical Physics, 2019
The Journal of Physical Chemistry C, 2019
The Journal of Physical Chemistry C, 2016
The Journal of Physical Chemistry C, 2016
The Journal of Physical Chemistry C, 2015
Journal of Modern Optics, 2012
The Editors would like to thank all those people who have offered their help by reviewing manuscr... more The Editors would like to thank all those people who have offered their help by reviewing manuscripts for Journal of Modern Optics. The success of the Journal is largely dependent on the quality of reviews we receive, and so your assistance in assuring high standards in this way is greatly appreciated. The Editors would like to extend a special thanks to those reviewers marked (*) below who, on three or more occasions in 2011, have provided timely and insightful reviews that have greatly assisted the Editors in deciding what to publish, and in helping authors to improve their manuscripts.
The Journal of Physical Chemistry C, 2016
Journal of chemical theory and computation, Jan 31, 2016
Optimizing the photovoltaic efficiency of dye-sensitized solar cells (DSSC) based on staggered ga... more Optimizing the photovoltaic efficiency of dye-sensitized solar cells (DSSC) based on staggered gap heterojunctions requires a detailed understanding of sub-band gap transitions in the visible from the dye directly to the substrate's conduction band (CB) (type-II DSSCs). Here, we calculate the optical absorption spectra and spatial distribution of bright excitons in the visible region for a prototypical DSSC, catechol on rutile TiO2(110), as a function of coverage and deprotonation of the OH anchoring groups. This is accomplished by solving the Bethe-Salpeter equation (BSE) based on hybrid range-separated exchange and correlation functional (HSE06) density functional theory (DFT) calculations. Such a treatment is necessary to accurately describe the interfacial level alignment and the weakly bound charge transfer transitions that are the dominant absorption mechanism in type-II DSSCs. Our HSE06 BSE spectra agree semiquantitatively with spectra measured for catechol on anatase TiO...
The discovery of carbon nanotubes by Iijima in 1991 has created a torrent of new research activit... more The discovery of carbon nanotubes by Iijima in 1991 has created a torrent of new research activities. Research on carbon nanotubes ranges from studying their fundamental properties, such as their electron band structure and plasma frequencies, to developing new applications, such as self-assembled nano-circuits and field emission displays. Robust models are now needed to enable a better understanding of the electronic response of carbon nanotubes. We use timedependent density functional theory to derive a two-fluid two-dimensional (2D) hydrodynamic model describing the collective response of a multiwalled carbon nanotube with dielectric media embedded inside or surrounding the nanotube. We study plasmon hybridization of the nanotube system in the UV range, the stopping force for ion channelling, the dynamical image potential for fast ions, channelled diclusters and point dipoles, and the energy loss for ions with oblique trajectories. Comparisons are made of results obtained from th...
A thorough understanding of the electronic structure is a necessary first step for the design of ... more A thorough understanding of the electronic structure is a necessary first step for the design of nanoelectronics, chemical/bio-sensors, electrocatalysts, and nanoplasmonics using graphene. As such, theoretical spectroscopic tech-niques to describe collective excitations of graphene are of fundamental importance. Starting from density functional theory (DFT), linear response time dependent DFT in frequency-reciprocal space within the random phase approxima-tion (TDDFT-RPA) is used to describe the loss function −={ε−1(q, ω)} for isolated graphene. To ensure any spurious interactions between layers are removed, both a radial cutoff of the Coulomb kernel, and extra vacuum directly at the TDDFT-RPA level are employed. A combination of both methods is found to provide a correct description of the electron energy loss spectra of isolated graphene, at a significant reduction in computational cost compared to standard methods. 1 Introduction In the last ten years, graphene [1,2, 3,4,5,6,7,8,...
∗Nano-Bio Spectroscopy Group and ETSF Scientific Development Centre, Depto. Fı́sica de Materiales... more ∗Nano-Bio Spectroscopy Group and ETSF Scientific Development Centre, Depto. Fı́sica de Materiales, Universidad del Paı́s Vasco and DIPC, Avenida de Tolosa 72, E-20018 San Sebastián, Spain; Phone:+34 943 01 8288 Fax:+34 943 01 8390 E-mail: duncan.mowbray@gmail.com †Nano-Bio Spectroscopy Group and ETSF Scientific Development Centre, Depto. Fı́sica de Materiales, Universidad del Paı́s Vasco, Centro de Fı́sica de Materiales CSIC-UPV/EHUMPC and DIPC, Av. Tolosa 72, E-20018 San Sebastián, Spain; Center for Atomic-scale Materials Design, Department of Physics, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark; Phone:+45 4525 3209 Fax:+45 4593 2399 E-mail: jumagala@fysik.dtu.dk ‡Nano-Bio Spectroscopy Group and ETSF Scientific Development Centre, Depto. Fı́sica de Materiales, Universidad del Paı́s Vasco and DIPC, Avenida de Tolosa 72, E-20018 San Sebastián, Spain; E-mail: ilarrazaarocena@gmail.com §Nano-Bio Spectroscopy Group and ETSF Scientific Development Centre, Depto. Fı́sica...
The Journal of Chemical Physics, 2019
The Journal of Physical Chemistry C, 2019
The Journal of Physical Chemistry C, 2016
The Journal of Physical Chemistry C, 2016
The Journal of Physical Chemistry C, 2015
Journal of Modern Optics, 2012
The Editors would like to thank all those people who have offered their help by reviewing manuscr... more The Editors would like to thank all those people who have offered their help by reviewing manuscripts for Journal of Modern Optics. The success of the Journal is largely dependent on the quality of reviews we receive, and so your assistance in assuring high standards in this way is greatly appreciated. The Editors would like to extend a special thanks to those reviewers marked (*) below who, on three or more occasions in 2011, have provided timely and insightful reviews that have greatly assisted the Editors in deciding what to publish, and in helping authors to improve their manuscripts.
The Journal of Physical Chemistry C, 2016
Journal of chemical theory and computation, Jan 31, 2016
Optimizing the photovoltaic efficiency of dye-sensitized solar cells (DSSC) based on staggered ga... more Optimizing the photovoltaic efficiency of dye-sensitized solar cells (DSSC) based on staggered gap heterojunctions requires a detailed understanding of sub-band gap transitions in the visible from the dye directly to the substrate's conduction band (CB) (type-II DSSCs). Here, we calculate the optical absorption spectra and spatial distribution of bright excitons in the visible region for a prototypical DSSC, catechol on rutile TiO2(110), as a function of coverage and deprotonation of the OH anchoring groups. This is accomplished by solving the Bethe-Salpeter equation (BSE) based on hybrid range-separated exchange and correlation functional (HSE06) density functional theory (DFT) calculations. Such a treatment is necessary to accurately describe the interfacial level alignment and the weakly bound charge transfer transitions that are the dominant absorption mechanism in type-II DSSCs. Our HSE06 BSE spectra agree semiquantitatively with spectra measured for catechol on anatase TiO...
The discovery of carbon nanotubes by Iijima in 1991 has created a torrent of new research activit... more The discovery of carbon nanotubes by Iijima in 1991 has created a torrent of new research activities. Research on carbon nanotubes ranges from studying their fundamental properties, such as their electron band structure and plasma frequencies, to developing new applications, such as self-assembled nano-circuits and field emission displays. Robust models are now needed to enable a better understanding of the electronic response of carbon nanotubes. We use timedependent density functional theory to derive a two-fluid two-dimensional (2D) hydrodynamic model describing the collective response of a multiwalled carbon nanotube with dielectric media embedded inside or surrounding the nanotube. We study plasmon hybridization of the nanotube system in the UV range, the stopping force for ion channelling, the dynamical image potential for fast ions, channelled diclusters and point dipoles, and the energy loss for ions with oblique trajectories. Comparisons are made of results obtained from th...