Ifor Samuel

Ifor David William Samuel

Postal address:
School of Physics & Astronomy
Physical Science Building
North Haugh
St Andrews
United Kingdom

E-mail: idws@st-andrews.ac.uk

Web address: http://www.st-andrews.ac.uk/~www_pa/PHP_Global/Staff_Info.php?id=70

Direct phone: +44 (0)1334 463114

Research overview

Polymer optoelectronics.

Most polymers, or plastics, are electrical insulators. However there is one class of polymers, known as ‘conjugated’ polymers which can conduct electricity. These materials are semiconductors, and open new directions in optoelectronics. They combine novel semiconducting electronic properties with the processing flexibility of polymers. When a voltage is applied to them, they emit light, providing an important new display technology that could give flat and even flexible displays. Semiconducting polymers can be used to make field effect transistors, solar cells, and even lasers. In the polymer optoelectronics group we seek to understand the physics of these remarkable materials and devices, with the aim of improving them. The research has both fundamental and applied aspects, and the main activities are:
– optical amplifiers
– wavelength scale microstructure
– new materials
– charge transport in LEDs
– understanding the light emission process

I am also researching fluorescence and its applications in medicine and biology.

For further information, see the Organic Semiconductor Centre and the Polymer Optoelectronics group website.

Recent Publications

Hot-Hole cooling controls the initial ultrafast relaxation in methylammonium lead iodide perovskite
Hedley, G. J., Quarti, C., Harwell, J. R., Prezhdo, O., Beljonne, D. & Samuel, I. D. W. 25 May 2018 In : Scientific Reports. 8, 9 p., 8115
Research output: Research - peer-reviewArticle

Flexible and ultra-lightweight polymer membrane lasers
Karl, M., Glackin, J. M. E., Schubert, M., Kronenberg, N. M., Turnbull, G. A., Samuel, I. D. W. & Gather, M. C. 1 May 2018 In : Nature Communications. 9, 7 p., 1525
Research output: Research - peer-reviewArticle

Morphological, chemical, and electronic changes of the conjugated polymer PTB7 with thermal annealing
Savikhin, V., Jagadamma, L. K., Purvis, L. J., Robertson, I., Oosterhout, S. D., Douglas, C. J., Samuel, I. D. W. & Toney, M. F. 27 Apr 2018 In : iScience. 2, p. 182-192 11 p.
Research output: Research - peer-reviewArticle

Engineered exciton diffusion length enhances device efficiency in small molecule photovoltaics
Sajjad, M. T., Blaszczyk, O., Krishnan Jagadamma, L., Roland, T., Chowdhury, M., Ruseckas, A. & Samuel, I. D. W. 19 Apr 2018 In : Journal of Materials Chemistry A. In press
Research output: Research - peer-reviewArticle

Exciton-polaron interactions in polyfluorene films with β phase
Montilla, F., Ruseckas, A. & Samuel, I. D. W. 12 Apr 2018 In : Journal of Physical Chemistry C.
Research output: Research - peer-reviewArticle

Carbon‐bridged p‐phenylenevinylene polymer for high‐performance solution‐processed distributed feedback lasers
Morales‐Vidal, M., Quintana, J. A., Villalvilla, J. M., Boj, P. G., Nishioka, H., Tsuji, H., Nakamura, E., Whitworth, G. L., Turnbull, G. A., Samuel, I. D. W. & Díaz‐García, M. A. 10 Apr 2018 In : Advanced Optical Materials. Early View, 8 p., 1800069
Research output: Research - peer-reviewArticle

An organic vortex laser
Stellinga, D., Pietrzyk, M., Glackin, J. M. E., Wang, Y., Bansal, A. K., Turnbull, G. A., Dholakia, K., Samuel, I. D. W. & Krauss, T. 27 Mar 2018 In : ACS Nano. 12, 3, p. 2389-2394 6 p.
Research output: Research - peer-reviewArticle

CuSCN nanowires as electrodes for p-type quantum dot sensitized solar cells: charge transfer dynamics and alumina passivation
Sajjad, M. T., Park, J., Gaboriau, D., Harwell, J. R., Odobel, F., Reiss, P., Samuel, I. D. W. & Aldakov, D. 8 Mar 2018 In : Journal of Physical Chemistry C. 122, 9, p. 5161-5170
Research output: Research - peer-reviewArticle

Ormosil-coated conjugated polymers for the detection of explosives in aqueous environments
Gillanders, R. N., Campbell, I. A., Glackin, J. M. E., Samuel, I. D. W. & Turnbull, G. A. 1 Mar 2018 In : Talanta. 179, p. 426-429
Research output: Research - peer-reviewArticle

Real-time observation of conformational switching in single conjugated polymer chains
Tenopala Carmona, F., Fronk, S., Bazan, G. C., Samuel, I. D. W. & Penedo-Esteiro, J. C. 16 Feb 2018 In : Science Advances. 4, 2, 13 p., eaao5786
Research output: Research - peer-reviewArticle

Flexible glass hybridized colloidal quantum dots for Gb/s visible light communications
Foucher, C., Sufyan, M. I., Guilhabert, B., Videv, S., Rajbhandari, S., Gomez Diaz, A., Chun, H., Vithanage, C. D. A., Turnbull, G. A., Samuel, I. D. W., Faulkner, G., O’Brien, D. C., Hass, H., Laurand, N. & Dawson, M. D. Feb 2018 In : IEEE Photonics Journal. 10, 1, 11 p., 8255623
Research output: Research - peer-reviewArticle

Strong coupling in a microcavity containing β-carotene
Grant, R. T., Jayaprakash, R., Coles, D. M., Musser, A., Liberato, S. D., Samuel, I. D. W., Turnbull, G. A., Clark, J. & Lidzey, D. G. 31 Jan 2018 In : Optics Express. 26, 3, p. 3320-3327 8 p.
Research output: Research - peer-reviewArticle

Advances in optical sensing of explosive vapours
Gillanders, R. N., Samuel, I. D. W., Turnbull, G. A., Campbell, I. A. & Glackin, J. M. E. 25 Jan 2018 Proceedings of the 6th International Conference on Photonics, Optics and Laser Technology (PHOTOPTICS 2018). Raposo, M. & Ribeiro, P. A. (eds.). SciTePress, p. 323-327
Research output: ResearchConference contribution

Time-resolved studies of energy transfer in thin films of green and red fluorescent proteins
Zajac, J. M., Schubert, M., Roland, T., Keum, C., Samuel, I. D. W. & Gather, M. C. 15 Jan 2018 In : Advanced Functional Materials. Early View
Research output: Research - peer-reviewArticle

Improved efficiency of PbS quantum dot sensitized NiO photocathodes with naphthalene diimide electron acceptor bound to the surface of the nanocrystals
Raissi, M., Sajjad, M. T., Farré, Y., Roland, T. J., Ruseckas, A., Samuel, I. D. W. & Odobel, F. 11 Jan 2018 In : Solar Energy Materials and Solar Cells. 181, p. 71-76 6 p.
Research output: Research - peer-reviewArticle

Colloidal nanocrystals: electrifying quantum dots for lasers
Samuel, I. D. W. Jan 2018 In : Nature Materials. 17, p. 9-10
Research output: Research - peer-reviewComment/debate

Исследование структуры объемного гетероперехода в органических солнечных элементах с помощью комбинации ультрамикротомирования и атомно - силовой микроскопии
Alekseev, A. M., Al-Afeef, A., Hedley, G. J., Kharintsev, S. S., Efimov, A. E., Yedrisov, A. T., Dyuzhev, N. A. & Samuel, I. D. W. 2018 In : Semiconductors. 52, 1, p. 105-111 7 p.
Research output: Research - peer-reviewArticle

Novel 4,8-benzobisthiazole copolymers and their field-effect transistor and photovoltaic applications
Conboy, G., Taylor, R. G. D., Findlay, N. J., Kanibolotsky, A. L., Inigo, A. R., Ghosh, S. S., Ebenhoch, B., Krishnan Jagadamma, L., Thalluri, G. K. V. V., Sajjad, M. T., Samuel, I. D. W. & Skabara, P. J. 7 Dec 2017 In : Journal of Materials Chemistry. 5, 45, p. 11927-11936 10 p.
Research output: Research - peer-reviewArticle

Air exposure induced recombination in PTB7:PC71BM solar cells
Thomson, S. A. J., Hogg, S. C., Samuel, I. D. W. & Keeble, D. J. 7 Nov 2017 In : Journal of Materials Chemistry A. 5, 41, p. 21926-21935
Research output: Research - peer-reviewArticle

Size dependence of efficiency of PbS quantum dots in NiO-based dye sensitised solar cells and mechanistic charge transfer investigation
Raissi, M., Sajjad, M. T., Pellegrin, Y., Roland, T. J., Jobic, S., Boujtita, M., Ruseckas, A., Samuel, I. D. W. & Odobel, F. 28 Oct 2017 In : Nanoscale. 9, 40, p. 15566-15575
Research output: Research - peer-reviewArticle

Charge separation and triplet exciton formation pathways in small molecule solar cells as studied by time-resolved EPR spectroscopy
Thomson, S., Niklas, J., Mardis, K. L., Mallares, C., Samuel, I. D. W. & Poluektov, O. G. 19 Oct 2017 In : Journal of Physical Chemistry C. 121, 41, p. 22707-22719
Research output: Research - peer-reviewArticle

Near-infrared fluorescence of silicon phthalocyanine carboxylate esters
Pal, A. K., Varghese, S., Cordes, D. B., Slawin, A. M. Z., Samuel, I. D. W. & Zysman-Colman, E. 25 Sep 2017 In : Scientific Reports. 7, 14 p., 12282
Research output: Research - peer-reviewArticle

Polymer colour converter with very high modulation bandwidth for visible light communications
Vithanage, D. A., Kanibolotsky, A. L., Rajbhandari, S., Manousiadis, P. P., Sajjad, M. T., Chun, H., Faulkner, G., O'Brien, D. C., Skabara, P. J., Samuel, I. D. W. & Turnbull, G. A. 21 Sep 2017 In : Journal of Materials Chemistry C. 5, 35, p. 8916-8920 5 p.
Research output: Research - peer-reviewArticle

Green perovskite distributed feedback lasers
Harwell, J. R., Whitworth, G. L., Turnbull, G. A. & Samuel, I. D. W. 15 Sep 2017 In : Scientific Reports. 7, 8 p., 11727
Research output: Research - peer-reviewArticle

Intermolecular states in organic dye dispersions: excimers vs aggregates
Musser, A. J., Rajendran, S. K., Georgiou, K., Gai, L., Grant, R. T., Shen, Z., Cavazzini, M., Ruseckas, A., Turnbull, G. A., Samuel, I. D. W., Clark, J. & Lidzey, D. G. 7 Sep 2017 In : Journal of Materials Chemistry C. 5, 33, p. 8380-8389 10 p.
Research output: Research - peer-reviewArticle

Emergent properties of an organic semiconductor driven by its molecular chirality
Yang, Y., Rice, B., Shi, X., Brandt, J. R., Correa da Costa, R., Hedley, G. J., Smilgies, D-M., Frost, J. M., Samuel, I. D. W., Otero-de-la-Roza, A., Johnson, E. R., Jelfs, K. E., Nelson, J., Campbell, A. J. & Fuchter, M. J. 22 Aug 2017 In : ACS Nano. 11, 8, p. 8329-8338 10 p.
Research output: Research - peer-reviewArticle

Charge carrier localised in zero-dimensional (CH3NH3)3Bi219 clusters
Ni, C., Hedley, G. J., Payne, J. L., Svrcek, V., McDonald, C., Jagadamma, L. K., Edwards, P., Martin, R., Jain, G., Carolan, D., Mariotti, D., Maguire, P., Samuel, I. D. W. & Irvine, J. T. S. 1 Aug 2017 In : Nature Communications. 8, 7 p., 170
Research output: Research - peer-reviewArticle

Correlating photovoltaic properties of PTB7-Th:PC71BM blend to photophysics and microstructure as a function of thermal annealing
Krishnan Jagadamma, L., Sajjad, M. T., Savikhin , V., Toney, M. & Samuel, I. D. W. 28 Jul 2017 In : Journal of Materials Chemistry A. 5, 28, p. 14646-14657 12 p.
Research output: Research - peer-reviewArticle

Barrierless slow dissociation of photogenerated charge pairs in high-performance polymer-fullerene solar cells
Vithanage, D. A., Matheson, A. B., Pranculis, V., Hedley, G. J., Pearson, S. J., Gulbinas, V., Samuel, I. D. W. & Ruseckas, A. 6 Jul 2017 In : Journal of Physical Chemistry C. 121, 26, p. 14060-14065 6 p.
Research output: Research - peer-reviewArticle

Blue-to-green emitting neutral Ir(III) complexes bearing pentafluorosulfanyl groups: a combined experimental and theoretical study
Pal, A. K., Henwood, A. F., Cordes, D. B., Slawin, A. M. Z., Samuel, I. D. W. & Zysman-Colman, E. 3 Jul 2017 In : Inorganic Chemistry. 56, 13, p. 7533–7544
Research output: Research - peer-reviewArticle

A low-cost, portable optical explosive-vapour sensor
Gillanders, R. N., Samuel, I. D. W. & Turnbull, G. A. Jun 2017 In : Sensors and Actuators B: Chemical. 245, p. 334-340
Research output: Research - peer-reviewArticle

Effect of annealing on exciton diffusion in a high performance small molecule organic photovoltaic material
Long, Y., Hedley, G. J., Ruseckas, A., Chowdhury, M., Roland, T. J., Serrano, L., Cooke, G. & Samuel, I. D. W. 3 May 2017 In : Applied Materials & Interfaces. 9, 17, p. 14945-14952
Research output: Research - peer-reviewArticle

Influence of optical material properties on strong coupling in organic semiconductor based microcavities
Tropf, L. C., Dietrich, C. P., Herbst, S., Kanibolotsky, A. L., Skabara, P. J., Würthner, F., Samuel, I. D. W., Gather, M. C. & Höfling, S. Apr 2017 In : Applied Physics Letters. 110, 15, 5 p., 153302
Research output: Research - peer-reviewArticle

Exciton diffusion length and charge extraction yield in organic bilayer solar cells
Siegmund, B., Sajjad, M. T., Widmer, J., Ray, D., Koerner, C., Riede, M., Leo, K., Samuel, I. D. W. & Vandewal, K. 28 Mar 2017 In : Advanced Materials. 29, 12, 5 p., 1604424
Research output: Research - peer-reviewArticle

Ultrafast Electronic Energy Transfer in an orthogonal molecular dyad
Wiebeler, C., Plasser, F., Hedley, G. J., Ruseckas, A., Samuel, I. D. W. & Schumacher, S. 2 Mar 2017 In : Journal of Physical Chemistry Letters. 8, 5, p. 1086-1092 7 p.
Research output: Research - peer-reviewArticle