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Your search keyword '"Lidzey, D. G."' showing total 189 results
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189 results on '"Lidzey, D. G."'

1. Superabsorption in an organic microcavity: towards a quantum battery

Author

Quach, J. Q., McGhee, K. E., Ganzer, L., Rouse, D. M., Lovett, B. W., Gauger, E. M., Keeling, J., Cerullo, G., Lidzey, D. G., and Virgili, T.

Subjects
Quantum Physics
Abstract

The rate at which matter emits or absorbs light can be modified by its environment, as dramatically exemplified by the widely-studied phenomenon of superradiance. The reverse process, superabsorption, is harder to demonstrate due to the challenges of probing ultrafast processes, and has only been seen for small numbers of atoms. Its central idea - superextensive scaling of absorption meaning larger systems absorb faster - is also the key idea underpinning quantum batteries. Here we implement experimentally a paradigmatic model of a quantum battery, constructed of a microcavity enclosing a molecular dye. Ultrafast optical spectroscopy allows us to observe charging dynamics at femtosecond resolution to demonstrate superextensive charging rates and storage capacity, in agreement with our theoretical modelling. We find that decoherence plays an important role in stabilising energy storage. Our work opens new opportunities for harnessing collective effects in light-matter coupling for nanoscale energy capture, storage, and transport technologies., Comment: 42 pages, 20 figures, 3 tables

Published
2020
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2. Nano-second exciton-polariton lasing in organic microcavities

Author

Putintsev, A., Zasedatelev, A., McGhee, K. E., Cookson, T., Georgiou, K., Sannikov, D., Lidzey, D. G., and Lagoudakis, P. G.

Subjects
Physics - Applied Physics, Condensed Matter - Soft Condensed Matter
Abstract

Organic semiconductors are a promising platform for ambient polaritonics. Several applications, such as polariton routers, and many-body condensed matter phenomena are currently hindered due to the ultra-short polariton lifetimes in organics. Here, we employ a single-shot dispersion imaging technique, using 4 nanosecond long non-resonant excitation pulses, to study polariton lasing in a $\lambda/2$ planar organic microcavity filled with BODIPY-Br dye molecules. At a power threshold density of $1.5 MW/cm^{2}$, we observe the transition to a quasi-steady state, 1.2 ns long-lived, single-mode polariton lasing and the concomitant superlinear increase of photoluminescence, spectral line-narrowing, and energy blueshift

Published
2020
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3. Non-radiative exciton energy transfer in hybrid organic-inorganic heterostructures

Author

Chanyawadee, S., Lagoudakis, P. G., Harley, R. T., Lidzey, D. G., and Henini, M.

Subjects
Condensed Matter - Other Condensed Matter
Abstract

Non-radiative optical energy transfer from a GaAs quantum well to a thin overlayer of an infrared organic semiconductor dye is unambiguously demonstrated. The dynamics of exciton transfer are studied in the time-domain using pump-probe spectroscopy at the donor site and fluorescence spectroscopy at the acceptor site. The effect is observed as simultaneous increase of the population decay rate at the donor and of the rise time of optical emission at the acceptor sites. The hybrid configuration under investigation provides an alternative non-radiative, non-contact pumping route to electrical carrier injection that overcomes the losses imposed by the associated low carrier mobility of organic emitters.

Published
2007
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14. Organic quantum batteries

Author

Quach, J. Q., primary, Virgili, T., additional, Cerullo, G., additional, McGhee, K. E., additional, Ganzer, L., additional, and Lidzey, D. G., additional

Published
2020
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16. Tin(iv) dopant removal through anti-solvent engineering enabling tin based perovskite solar cells with high charge carrier mobilities

Author

Bandara, R. M. I., primary, Jayawardena, K. D. G. I., additional, Adeyemo, S. O., additional, Hinder, S. J., additional, Smith, J. A., additional, Thirimanne, H. M., additional, Wong, N. C., additional, Amin, F. M., additional, Freestone, B. G., additional, Parnell, A. J., additional, Lidzey, D. G., additional, Joyce, H. J., additional, Sporea, R. A., additional, and Silva, S. R. P., additional

Published
2019
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17. High sensitivity organic inorganic hybrid X-ray detectors with direct transduction and broadband response

Author

Thirimanne, H. M., primary, Jayawardena, K. D. G. I., additional, Parnell, A. J., additional, Bandara, R. M. I., additional, Karalasingam, A., additional, Pani, S., additional, Huerdler, J. E., additional, Lidzey, D. G., additional, Tedde, S. F., additional, Nisbet, A., additional, Mills, C. A., additional, and Silva, S. R. P., additional

Published
2018
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19. Single molecule spectroscopy of red- and green-emitting fluorene-based copolymers.

Author

Khalil, G. E., Adawi, A. M., Fox, A. M., Iraqi, A., and Lidzey, D. G.

Subjects
POLYMERS, OPTICAL properties, THIOPHENES, POLARIZATION microscopy, COMPARATIVE studies
Abstract

Single molecule fluorescence spectroscopy is used to study the optical properties of two polymers: a fluorene-based statistical copolymer that contains a low fraction (10%) of a red-emitting thiophene group, and the green-emitting polymer poly(9,9-dioctylfluorene-alt-benzothiadiazole). These polymers were studied when isolated at a low concentration in a polymer matrix (either polynorbornene or polystyrene). For the red-emitting polymer, we compare the relative emission intensity from the green-emitting benzothiadiazole groups with the red-emitting thiophene. We find that red emission from the thiophenes is significantly suppressed in the single molecule regime, suggesting that interchain energy transfer dominates intrachain processes in such polyfluorene copolymers. We then use fluorescence spectroscopy and polarization anisotropy measurements to show that the conformations of both polymers are dependent on their host matrix, adopting a more collapsed, globular conformation in polystyrene and a more extended chain conformation in polynorbornene. [ABSTRACT FROM AUTHOR]

Published
2009
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20. Mapping exciton quenching in photovoltaic-applicable polymer blends using time-resolved scanning near-field optical microscopy.

Author

Cadby, A., Khalil, G., Fox, A. M., and Lidzey, D. G.

Subjects
FLUORESCENCE, MACROMOLECULES, SCANNING probe microscopy, NEAR-field microscopy, LUMINESCENCE
Abstract

We have used time-resolved scanning near-field microscopy to image the fluorescence decay lifetime across a phase-separated blend of the photovoltaic-applicable polymers poly(9,9′-dioctylfluorene-alt-benzothiadiazole) (F8BT) and poly(9,9′-dioctylfluorene-alt-bis- N,N′-(4-butylphenyl)-bis-N,N′-phenyl-1,4-phenylenediamine) (PFB). We show that the efficiency of local fluorescence quenching is composition dependent, with excitons on F8BT molecules being more effectively quenched when F8BT is trapped at a low concentration in a PFB-rich phase. Despite such presumed differences in charge-carrier generation efficiency, our results demonstrate that charge extraction from F8BT:PFB devices is the most dominant mechanism limiting their operational efficiency. [ABSTRACT FROM AUTHOR]

Published
2008
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21. Photoluminescence emission and Raman scattering polarization in birefringent organic microcavities in the strong coupling regime.

Author

Krizhanovskii, D. N., Butté, R., Connolly, L. G., Tartakovskii, A. I., Lidzey, D. G., Skolnick, M. S., and Walker, S.

Subjects
PHOTOLUMINESCENCE, RAMAN effect
Abstract

We have investigated the polarization properties of photoluminescence and Raman scattering in strongly coupled organic microcavities containing cyanine dye J aggregates. The birefringence of radially aligned J aggregates results in a large energy splitting of polariton modes when the electric field of the incoming laser light is perpendicular or parallel to the alignment direction. This splitting allows the degree of polarization of doubly resonant Raman processes involving the vibrational modes of J aggregates to be controlled, where the ingoing and outgoing channels are in resonance with the lower polariton branch. As well as providing insight into the properties of polaritons in organic microcavities, these experiments are a sensitive probe of alignment effects arising during the spin-coating deposition process. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Published
2003
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22. Hybrid organic-inorganic polariton laser

Author

Paschos, G. G., primary, Somaschi, N., additional, Tsintzos, S. I., additional, Coles, D., additional, Bricks, J. L., additional, Hatzopoulos, Z., additional, Lidzey, D. G., additional, Lagoudakis, P. G., additional, and Savvidis, P. G., additional

Published
2017
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23. Efficient multilayer electroluminescence devices with...

Author

O'Brien, D., Bleyer, A., Lidzey, D. G., Bradley, D. D. C., and Tsutsui, T.

Subjects
POLYMERS, ELECTROLUMINESCENT devices
Abstract

Studies the use of a highly luminescent conjugated polymer as an emissive layer in single and multilayer electroluminescence devices. External quantum efficiencies; Optimization of the injection and transport of each carrier type; Introduction of energy offsets at the polymer/polymer interface.

Published
1997
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24. Hybrid polaritons in strongly coupled microcavities: experiments and models

Author

Lidzey, D. G., Wenus, J., Whittaker, D. M., Itskos, Grigorios, Stavrinou, P. N., Bradley, D. D. C., Murray, R., and Itskos, Grigorios [0000-0003-3971-3801]

Subjects
Photon, Photoluminescence, Thin films, Exciton, Population, Biophysics, Polaritons, Physics::Optics, Biochemistry, Molecular physics, J-aggregates, law.invention, Scattering, law, Polariton, Semiconducting organic compounds, education, Semiconductor quantum wells, Quantum well, Mathematical models, Photons, education.field_of_study, Condensed matter physics, Condensed Matter::Other, Chemistry, Heterojunction, General Chemistry, Condensed Matter Physics, Optical microcavity, Atomic and Molecular Physics, and Optics, Microcavities, Heterojunctions, Hybrid-states, Excitons, Quantum-wells
Abstract

We describe the fabrication of one-dimensional quantum microcavities containing two different layers of molecular J-aggregates. We show that strong coupling can occur between the confined cavity photon mode and the two different molecular exciton modes, leading to the appearance of new 'hybrid' polaritonic modes. Such hybrid states can be described in terms of a superposition of the cavity photon and the two excitonic states. We characterise such cavities as a function of external viewing angle by measuring both the white-light reflectivity and photoluminescence emission following non-resonant optical excitation. We apply a simple model to describe the photoluminescence emission from the cavity by assuming a transfer of population between the different hybrid-polariton modes. We describe the predictions of our model and show that it provides a reasonable qualitative description of the emission. We then use a transfer matrix scattering model to calculate the reflectivity spectra of a cavity, based on an organic semiconductor layer composed of a thin film of J-aggregates deposited onto an inorganic heterostructure containing three InGaP quantum wells. Our results demonstrate that optical hybridisation may be expected between the organic and inorganic excitons in suitably designed structures. © 2004 Elsevier B.V. All rights reserved. 110 4 SPEC. ISS. 347 353 Cited By :17

Published
2004
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35. Imaging Joule heating in a conjugated-polymer light-emitting diode using a scanning thermal microscope.

Author

Boroumand, F. A., Voigt, M., Lidzey, D. G., Hammiche, Azzedine, Hill, G., Boroumand, F. A., Voigt, M., Lidzey, D. G., Hammiche, Azzedine, and Hill, G.

Abstract

We have used a scanning thermal microscope to image Joule heating in a conjugated-polymer light-emitting diode (LED). Our LEDs had an active diameter of 100 µm, which was defined using an insulating layer of silicon nitride patterned onto the LED anode. At an average power input of 0.2 mW into the LED, we find that the center of the cathode is some 0.2 K warmer than its periphery. The observed temperature distribution across the pixel is slightly asymmetric, an effect which may be correlated with spatial inhomogeneity in the local current density across the device. We present a finite element analysis thermal model which is able to accurately describe the observed temperature distribution across the LED cathode.

Published
2004

48. Polymer-based solar cells having an active area of 1.6 cm2 fabricated via spray coating.

Author

Scarratt, N. W., Griffin, J., Wang, T., Zhang, Y., Yi, H., Iraqi, A., and Lidzey, D. G.

Subjects
POLYMERS, SOLAR cells, OPTICAL beam induced current
Abstract

We demonstrate the fabrication of polymer solar cells in which both a PEDOT:PSS hole transport and a PCDTBT:PC71BM photoactive layer are deposited by spray-casting. Two device geometries are explored, with devices having a pixel area of 165 mm2 attaining a power conversion efficiency of 3.7%. Surface metrology indicates that the PEDOT:PSS and PCDTBT:PC71BM layers have a roughness of 2.57 nm and 1.18 nm over an area of 100 μm2. Light beam induced current mapping reveals fluctuations in current generation efficiency over length-scales of ~2 mm, with the average photocurrent being 75% of its maximum value. [ABSTRACT FROM AUTHOR]

Published
2015
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