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School of Physics and Astronomy

James Kneller


Research Student

Telephone: 020 7882 6570
Room Number: G. O. Jones Building, Room 211


1st Supervisor: Dr. Theo Kreouzis
2nd Supervisor: Dr. Robert Donnan

Project Title: Optically Induced Dielectric Changes in Semiconducting Polymers for RF Applications.
Project Description:

The purpose of this project is to experimentally investigate different organic compositions and fabrication methods for tuneable dielectric applications, and then to measure the dielectric constant of said organic semiconductors

The purpose of this project is to experimentally investigate the dielectric properties of organic semiconductors, namely of a 95% poly(3-hexylthiophene):5% phenyl-C61-butyric acid methyl ester blends, measuring in the dark and under white light illumination by quasi-optical transmissometry, terahertz time-domain spectroscopy, Time of Flight and Impedance Spectroscopy. We use different and fabrication methods such as spin coating, drop casting and hot-press to make our devices to test. We investigate these materials to for tuneable dielectric applications in conjunction with the EECS Antenna group, with the aim of creating a optically controlled dynamic lens for radio/terahertz waves.



Engineering and Physical Sciences Research Council (EPSRC)


  1. A.S. Andy, J.W. E. Kneller, O. Sushko, R. Dubrovka, C. Parini, T. Kreouzis and R. Donnan, Appl. Phys. Express, 11 061601 (2018).
  2. B. C. Schroeder, T. Kurosawa, T. Fu, Y. Chiu, J. Mun, G. Wang, X. Gu, L. Shaw, J.W. E. Kneller, T. Kreouzis, M. F. Toney, and Z. Bao, Advanced Functional Materials 27 (34), 1701973 (2017).
  3. J. W. E. Kneller, “Optically induced dielectric changes in poly(3-hexylthiophene) (P3HT) based structures”, Photon16 Conference - Oral Presentation, 2016
  4. A. Andy, R. Dubrovka, T. Kreouzis, and R. S. Donnan, ``An Optically Controlled Phase Shifter for Antenna Array Beam Steering,``9th European Conference on Antennas and Propagation (EuCAP), Apr. 2015, pp.1-4.
  5. A. Andy, J. W. E. Kneller, R. Dubrovka, T. Kreouzis, and R. S. Donnan, in 46th European Microwave Conference (EuMC), Oct. 2016, pp. 1-4.
  6. A. S. Andy, J. W. E. Kneller, O. Sushko, R. Dubrovka, C. G. Parini, T. Kreouzis, R. S. Donnan, ``Dynamic Organic Lens using Photosensitive Semiconductor (P3HT:PCBM) for Millimeter-wave Applications", 42nd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz), Aug. 2017, \textbf{ pp.????}.
  7. R. Dubrovka, O. Sushko, M. Pigeon, P. Alizadeh, A. S. Andy, R. S. Donnan, C. G. Parini, J. W. E. Kneller, T. Kreouzis, R. Dubrovka et al., "Measurements of non-linear sub-THz quasi-optical devices," 2017 XI International Conference on Antenna Theory and Techniques (ICATT), Kiev, 2017, pp. 9-13. DOI: 10.1109/ICATT.2017.7972576