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

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: Contribution to journalArticle

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: Contribution to journalArticle

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: Contribution to journalArticle

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. 13 Sep 2017 In : Journal of Physical Chemistry C. Just Accepted
Research output: Contribution to journalArticle

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. 7 Sep 2017 In : Nanoscale. Accepted Manuscript
Research output: Contribution to journalArticle

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: Contribution to journalArticle

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: Contribution to journalArticle

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: Contribution to journalArticle

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. 5 Jul 2017 In : Journal of Materials Chemistry C. 10 p.
Research output: Contribution to journalArticle

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: Contribution to journalArticle

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. 8 Jun 2017 In : Journal of Materials Chemistry A. In press, 12 p., TA-ART-04-2017-003144
Research output: Contribution to journalArticle

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: Contribution to journalArticle

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: Contribution to journalArticle

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: Contribution to journalArticle

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: Contribution to journalArticle

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: Contribution to journalArticle

Single cell induced optical confinement in biological lasers
Karl, M., Dietrich, C. P., Schubert, M., Samuel, I. D. W., Turnbull, G. A. & Gather, M. C. 1 Mar 2017 In : Journal of Physics D : Applied Physics. 50, 8, 9 p., 084005
Research output: Contribution to journalArticle

MIMO visible light communications using a wide field-of-view fluorescent concentrator
Mulyawan, R., Chun, H., Gomez, A., Rajbhandari, S., Faulkner, G., Manousiadis, P. P., Vithanage, D. A., Turnbull, G. A., Samuel, I. D. W., Collins, S. & O'Brien, D. 1 Feb 2017 In : IEEE Photonics Technology Letters. 29, 3, p. 306-309 4 p., 7809099
Research output: Contribution to journalArticle

A saturated red color converter for visible light communication using a blend of star-shaped organic semiconductors
Sajjad, M. T., Manousiadis, P., Orofino, C., Kanibolotsky, A., Findlay, N., Rajbhandari, S., Vithanage, C. D. A., Chun, H., Faulkner, G., O'Brien, D., Skabara, P., Turnbull, G. A. & Samuel, I. D. W. Jan 2017 In : Applied Physics Letters. 110, 1, 4 p., 013302
Research output: Contribution to journalArticle

Tuning crystalline ordering by annealing and additives to study its effect on exciton diffusion in a polyalkylthiophene copolymer
Chowdhury, M., Sajjad, M. T., Savikhin, V., Hergue, N., Sutija, K., Oosterhout, S., Toney, M. F., Dubois, P., Ruseckas, A. & Samuel, I. D. W. 2017 In : Physical Chemistry Chemical Physics. 19, p. 12441-12451
Research output: Contribution to journalArticle

Exploring the self-assembly and energy transfer of dynamic supramolecular iridium-porphyrin systems
Rota Martir, D., Hedley, G. J., Cordes, D. B., Slawin, A. M. Z., Escudero, D., Jacquemin, D., Kosikova, T., Philp, D., Dawson, D. M., Ashbrook, S. E., Samuel, I. D. W. & Zysman-Colman, E. 22 Nov 2016 In : Dalton Transactions. 45, 43, p. 17195-17205 10 p.
Research output: Contribution to journalArticle

Organic light-emitting diodes for optogenetic stimulation of Drosophila larvae
Murawski, C., Morton, A., Samuel, I. D. W., Pulver, S. & Gather, M. C. 14 Nov 2016 Proceedings, Light, Energy and the Environment. Optical Society of American (OSA), 3 p. JW4A.9. (Fourier Transform Spectroscopy)
Research output: Chapter in Book/Report/Conference proceedingConference contribution

Synthesis, properties and Light-Emitting Electrochemical Cell (LEEC) device fabrication of cationic Ir(III) complexes bearing electron-withdrawing groups on the cyclometallating ligands
Pal, A. K., Cordes, D. B., Slawin, A. M. Z., Momblona, C., Orti, E., Samuel, I. D. W., Bolink, H. & Zysman-Colman, E. 17 Oct 2016 In : Inorganic Chemistry. 55, 20, p. 10361-10376
Research output: Contribution to journalArticle

Controlling the emission efficiency of blue-green iridium(III) phosphorescent emitters and applications in solution-processed organic light-emitting diodes
Sajjad, M. T., Sharma, N., Pal, A. K., Hasan, K., Xie, G., Kölln, L. S., Hanan, G. S., Samuel, I. D. W. & Zysman-Colman, E. 14 Oct 2016 In : Journal of Materials Chemistry. 4, 38, p. 8939-8946 8 p.
Research output: Contribution to journalArticle

Nanoimprinted distributed feedback lasers of solution processed hybrid perovskites
Whitworth, G. L., Harwell, J. R., Miller, D. N., Hedley, G. J., Zhang, W., Snaith, H. J., Turnbull, G. A. & Samuel, I. D. W. 3 Oct 2016 In : Optics Express. 24, 21, p. 23677-23684 8 p.
Research output: Contribution to journalArticle

Self-trapping and excited state absorption in fluorene homo-polymer and copolymers with benzothiadiazole and tri-phenylamine
Denis, J-C., Ruseckas, A., Hedley, G. J., Matheson, A. B., Paterson, M. J., Turnbull, G. A., Samuel, I. D. W. & Galbraith, I. 21 Aug 2016 In : Physical Chemistry Chemical Physics. 18, 31, p. 21937-21948 12 p.
Research output: Contribution to journalArticle

Probing the energy levels of perovskite solar cells via Kelvin probe and UV ambient pressure photoemission spectroscopy
Harwell, J. R., Baikie, T. K., Baikie, I. D., Payne, J. L., Ni, C., Irvine, J. T. S., Turnbull, G. A. & Samuel, I. D. W. 7 Aug 2016 In : Physical Chemistry Chemical Physics. 18, 29, p. 19738-19745 8 p.
Research output: Contribution to journalArticle

Wide field of view fluorescent antenna for visible light communications beyond the étendue limit
Manousiadis, P., Rajbhandari, S., Mulyawan, R., Vithanage, C. D. A., Chun, H., Faulkner, G., O'Brien, D. C., Turnbull, G. A., Collins, S. & Samuel, I. D. W. 20 Jul 2016 In : Optica. 3, 7, p. 702-706 5 p.
Research output: Contribution to journalArticle

BODIPY star-shaped molecules as solid state colour converters for visible light communications
Vithanage, C. D. A., Manousiadis, P., Sajjad, M. T., Rajbhandari, S., Chun, H., Orofino, C., Cortizo-Lacalle, D., Kanibolotsky, A., Faulkner, G., Findlay, N., O'Brien, D., Skabara, P., Samuel, I. D. W. & Turnbull, G. A. 6 Jul 2016 In : Applied Physics Letters. 109, 1, 013302
Research output: Contribution to journalArticle

Optofluidic distributed feedback lasers with evanescent pumping: reduced threshold and angular dispersion analysis
Karl, M., Whitworth, G. L., Schubert, M., Dietrich, C. P., Samuel, I. D. W., Turnbull, G. A. & Gather, M. C. 27 Jun 2016 In : Applied Physics Letters. 108, 26, 261101
Research output: Contribution to journalArticle

Morphology-specific inhibition of β-amyloid aggregates by 17β-hydroxysteroid dehydrogenase type 10
Aitken, L., Quinn, S. D., Perez-Gonzalez, D. C., Samuel, I. D. W., Penedo-Esteiro, J. C. & Gunn-Moore, F. J. 2 Jun 2016 In : ChemBioChem. 17, 11, p. 1029-1037
Research output: Contribution to journalArticle

Effect of a high boiling point additive on the morphology of solution-processed P3HT-fullerene blends
Long, Y., Ward, A. J., Ruseckas, A. & Samuel, I. D. W. Jun 2016 In : Synthetic Metals. 216, p. 23-30 8 p.
Research output: Contribution to journalArticle

The influence of blend ratio and processing additive on free carrier yield and mobility in PTB7:PC71BM photovoltaic solar cells
Pranculis, V., Ruseckas, A., Vithanage, D. A., Hedley, G. J., Samuel, I. D. W. & Gulbinas, V. 12 May 2016 In : Journal of Physical Chemistry C. 120, 18, p. 9588-9594
Research output: Contribution to journalArticle

Solubilised bright blue-emitting iridium complexes for solution processed OLEDs
Henwood, A. F., Bansal, A. K., Cordes, D. B., Slawin, A. M. Z., Samuel, I. D. W. & Zysman-Colman, E. 7 May 2016 In : Journal of Materials Chemistry C. 4, 17, p. 3726-3737 12 p.
Research output: Contribution to journalArticle

Solution-processable silicon phthalocyanines in electroluminescent and photovoltaic devices
Zysman-Colman, E., Ghosh, S. S., Xie, G., Varghese, S., Chowdhury, M., Sharma, N., Cordes, D. B., Slawin, A. M. Z. & Samuel, I. D. W. 13 Apr 2016 In : Applied Materials & Interfaces. 8, 14, p. 9247−9253
Research output: Contribution to journalArticle