We are inviting abstracts for early career research talks and poster presentations. Please send to: cpe-admin@imperial.ac.uk. The RSC is offering three £100 RSC book vouchers from Materials Horizons, Journal of Materials Chemistry C and RSC Applied Interfaces for poster prizes.
Agenda and abstracts will be posted as they are received
13 July 2026
Confirmed speakers include:
- Prof Alan Drew, Queen Mary University London, Radiation detection using solution processed organic (and organic-inorganic hybrid) films
- Dr Imalka Jayawardena, University of Surrey
14 July 2026
Confirmed speakers include:
- Prof Sean Collins, Imperial College London, Linking nanoscale chemical and structural disorder to optoelectronic properties in organic and perovskite semiconductors
- Prof Daan Arroo, Imperial College London
- Dr Flurin Eisner, Queen Mary University London
- Prof Calum Ferguson, University of Birmingham
Attendance is free, but we ask that you do register: Registration for the 2026 CPE Annual Symposium – Fill in form
ABSTRACTS
From imaging to implantable dosimeters: The journey of bulk heterojunction radiation sensors
Dr Imalka Jayawardena
Advanced Technology Institute, School of Computer Science and Electronic Engineering, University of Surrey, Guildford, Surrey, GU2 7XH.
X-ray detectors are a key element in modern healthcare diagnostics, cancer therapy, homeland security and non-destructive evaluation among many fields. However, the potential applications of X-ray detectors are limited by several factors including the system cost, areal limitations, and the requirement for thick crystals for efficient X-ray attenuation which in turn limits conformability on complex shapes and imposes a requirement for high operating voltages for efficient charge extraction/signal generation.
The use of bulk heterojunctions comprising of organic semiconductors and X-ray attenuating nanoparticles have emerged as an alternate technology that has the can address some of the limitations with conventional X-ray detector technologies. For example, the solution processable nature of these blends allows for fabrication of large area detectors on flexible substrates that can conform to complex shapes.
Here I will discuss the progress made by our group over the last decade on pushing the application space of these detectors. Starting from our observations and developments on the unusual broadband response (from keV to MeV range) of this system[1], I will discuss some of our early work on rigid imaging systems[2], to more conformable dose mapping systems targeting improved cancer therapy[3]. The talk will also discuss how we overcame rather high dark currents [4] through a simple device engineering step and how in our recent work, we are expanding the application space of these detectors to implantable architectures [5,6] as a probe for dose measurement closer to tumor sites.
References
[1] Thirimanne, H.M., Jayawardena, K.D.G.I., Parnell, A.J. et al. Nat Commun 9, 2926 (2018). [2] Jayawardena, K.D.G.I., Thirimanne, H.M., Tedde, S.F. et al. ACS Nano 13, 6973 (2019). [3] Thirimanne, H.M., Jayawardena, K.D.G.I., Nisbet A. et al. IEEE Trans. Nucl. Sci. 67 (2020). [4] Nanayakkara M.P.A., Matjačić, L., Wood, S. et al. Adv. Func. Mater. 31, 2008482 [5] Nanayakkara, M.P.A., Masteghin, M.G., Basiricò, L. et al. Adv. Sci. 9, 2101746 (2022). [6] Nanayakkara, M.P.A., He, Q. Ruseckas, A. et al. Adv. Sci. 10 (35), 2304261 (2023).
Linking nanoscale chemical and structural disorder to optoelectronic properties in organic and perovskite semiconductors
Prof Sean Collins
Department of Materials, Imperial College London
Despite sustained progress in the performance characteristics of organic semiconductors and halide perovskites, many features of structural and chemical heterogeneity remain poorly understood. Probing how structural and compositional heterogeneity precisely modify properties is crucial for developing new interventions for the fabrication of devices with improved stability throughout device operation. Advances in low-dose, nanometre-resolved electron diffraction have enabled access to this information for linking nanoscale structure to characteristics underpinning energy transport mechanisms [1] and device ageing [2]. When combined with spectroscopy in the scanning transmission electron microscope, diffraction tools can offer a direct means to link optical properties to nanoscale structures [3]. This presentation will highlight ongoing work to probe the role of localised, crystallographic defects [4] (including dislocations [5]), crystalline and amorphous phase separation in polymer blend semiconductors [6], as well as compositional heterogeneity in mixed anion lead halide perovskite nanocrystals. Respectively, these observations link disorder in perylene diimide (PDI) ‘nanobelts’ to a reduction in the exciton diffusion coefficient by over two orders of magnitude [4] and elaborate how anion composition modifies the Stokes shift and exciton radius in halide perovskites. These examples underscore the need to further progress multiscale structural and spectroscopic probes to unravel the mechanisms limiting durable performance.
[1] A.J. Sneyd et a. Sci. Adv. 7 (2021) eabh4232.
[2] S. Yoon et al. ACS Energy Lett. 10 (2025) 541–551.
[3] J. Hou et al. Science 374 (2021) 621–625.
[4] C.J.H. Smalley et al. Sci. Adv. 12 (2026) eaed0037.
[5] S.T. Pham et al. Nat. Mater. 24 (2025) 682–687.
[6] S.T. Pham, A.F. Sapnik, S.M. Collins, Small Methods (2026) e70719.