In memoriam Alasdair James Campbell (11 May 1961–27 February 2021)

Life and biography

Alasdair James Campbell, Professor of Solid-State Physics at Imperial College London, passed away on 27th February 2021 at the age of 59. Alasdair, or ‘Al’ as he was known to his colleagues, students and friends, earned his Bachelor's degree in Physics with Astrophysics at Queen Mary College, London, UK, before moving to the Chelsea College of Science and Technology (also in London) for a Master's degree in Solid State Physics. He returned to Queen Mary for his doctoral research, where he studied semiconducting polymers in the Department of Materials, earning his doctorate in 1992 for his investigations into polydiacetylenes.¹ After a short postdoc at King's College London, Al moved to the University of Sheffield, where he joined the group of Prof. Donal Bradley. In 2000, Al moved with Prof. Bradley to Imperial College London, establishing his own research group and becoming a full Professor in 2016, within the Experimental Solid State Physics group. Al was a founding member of the Centre for Processable Electronics (formally Centre for Plastic Electronics).

Alongside his family, science was the central focus of Al's life. He was immensely collaborative, and never short of useful suggestions for experiments, project partners or research opportunities. He was fascinated by the world beyond the lab, whether that be international travel or his fondness for Romantic era paintings, mythology and Egyptology. In between PhD theses and journals, his office bookshelves were lined with graphic novels, music CDs, and sci-fi. His friends, students and colleagues will remember Al's kindness, his humour and love of a good party.

Scientific achievements

Al was an exceptional scientist who made considerable impact in the fundamental research of state-of-the-art display technologies, printed photodetectors and transistors, neuromorphic computing and organic biomedical sensors. His work influenced the fields of materials chemistry, bioelectronics and materials science by providing the mechanistic understanding and methods to exploit underlying solid-state physics phenomena.

Al's research focussed on the development of organic semiconductor materials and devices. Arriving at Sheffield in the mid-nineties, Al was tasked with investigating light-emitting polymers, devising experiments that unravelled their charge transport physics. Working alongside Prof. David Lidzey, Al assembled bespoke apparatus, laboured over LabVIEW scripts and meticulously collected and analysed data. This was characteristic of his approach to science: he never was a fan of off-the-shelf instrumentation, preferring to construct his own. This skill enabled Al to pioneer the use of advanced spectroscopic techniques that delivered mechanistic understanding of trap states in organic matter.^2–6 He approached these studies with outstanding care, poring over experimental data and comparing it to theoretical models.

Al took his interest in charge transport phenomena to Imperial College, and established himself as a key figure in the university's drive to increase research capacity in the area of ‘plastic electronics’. New materials, collaborators and pieces of equipment considerably expanded Al's repertoire: he quickly became the go-to academic for rigorous discussions and analysis of device data. His fundamental understanding of structure–property relationships in organic, inorganic and hybrid semiconductors, coupled with his deep appreciation for electronics, allowed Al to push new boundaries. Amongst these were the development of large-area printing technologies, resulting in flexible organic light-emitting diodes (OLEDs), organic field-effect transistors, and polymer-based sensors for biochemical detection.^7–10 Al was a key academic partner in multiple international research consortiums, bringing industry and academia together to tackle challenging application-driven problems.

Ever on the quest for innovation, Al's most recent research took him to the world of chiral functional materials, combining his knowledge of polyfluorenes with small chiral molecules to generate circularly polarised (CP) luminescence and absorption in OLEDs and photodetectors. Such devices have application in creating efficient displays, quantum optics, bioimaging and encrypted communications. In close collaboration with Prof. Matthew Fuchter, these ground-breaking studies were crucial to the emerging field of CP-related photonics.^11–17 Al was determined to understand the processes that give rise to CP emission and led a sizeable research effort in this area. His excitement for finding answers to tricky questions was nothing short of inspiring. Al would spend weeks considering new data sets, building optical models, and not being afraid to challenge conventional thinking. This made him so uniquely respected in the broad area of organic electronics – and in fields beyond.

Academic service

Al was deeply involved with many professional bodies, most notably SPIE, the International Society for Optics and Photonics, and SID, the Society for Information Display. He served on the programme committee of SPIE's Photonic Devices Conference for several years, building important collaborations and enjoying the sun in San Diego. Al's energy and excitement for innovations in light-emitting materials and display technologies resulted in Imperial College London hosting many SID workshops, which became important events in the calendar of the UK semiconductor community. At these workshops, Al connected some of the world's leading researchers and industry experts, creating valuable partnerships and driving new research directions. These sessions served as important training programmes for the next generation of scientists, teaching them the fundamentals of device physics and molecular design, providing industrial insight and career opportunities. His genuine curiosity for research outside of his specialty were essential for their success.

Al was not only a remarkable researcher, but an immensely gifted teacher and a caring mentor. His knowledge and enthusiasm for device physics was unparalleled and instantly apparent to his students. He inspired countless generations of students, many of whom have gone on to hold important positions in industry and academia. Al would effortlessly intersperse recent discoveries, personal anecdotes and ideas, alongside deep mechanistic discussions of the underlying physics. Al understood the importance of providing research opportunities to early career researchers. He would spend weeks designing projects, reading reports and helping students as they identified their own interests. He was generous with his time: his office door was always open; no e-mail went ignored and no query was too trivial. This generosity and commitment to education was unwavering: he continued to deliver his popular device physics course until the week that he died. The scientific community will miss him deeply.

To honour Al's scientific legacy and give thanks to his dedication, mentorship and friendship, a Joint Special Collection celebrating his life is being launched by the Journal of Materials Chemistry C and Sustainable Energy & Fuels. Contributions to the collection are by invitation only.

Select publications

1. A. J. Campbell, University of London, 1992.
2. A. J. Campbell, D. D. C. Bradley and D. G. Lidzey, J. Appl. Phys., 1997, 82, 6326–6342.
3. A. J. Campbell, D. D. C. Bradley, T. Virgili, D. G. Lidzey and H. Antoniadis, Appl. Phys. Lett., 2001, 79, 3872–3874.
4. A. J. Campbell, D. D. C. Bradley and H. Antoniadis, Appl. Phys. Lett., 2001, 79, 2133–2135.
5. T. Kreouzis, D. D. C. Bradley and A. J. Campbell, Proc. SPIE, 2004, 5214, 141–149.
6. A. J. Campbell, D. D. C. Bradley and D. G. Lidzey, J. Appl. Phys., 1997, 82, 6326–6342.
7. S. G. Higgins, B. V. O. Muir, J. Wade, J. Chen, B. Striedinger, H. Gold, B. Stadlober, M. Caironi, J. Kim, J. H. G. Steinke and A. J. Campbell, Adv. Electron. Mater., 2015, 1, 1500024.
8. S. G. Higgins, B. V. O. Muir, G. Dell’Erba, A. Perinot, M. Caironi and A. J. Campbell, Adv. Electron. Mater., 2016, 2, 1500272.
9. Q. Thiburce and A. J. Campbell, Adv. Electron. Mater., 2017, 3, 1600421.
10. J. E. Tyrrell, M. G. Boutelle and A. J. Campbell, Adv. Funct. Mater., 2021, 31, 2007086.
11. Y. Yang, R. C. da Costa, D.-M. Smilgies, A. J. Campbell and M. J. Fuchter, Adv. Mater., 2013, 25, 2624–2628.
12. L. Wan, J. Wade, X. Shi, S. Xu, M. J. Fuchter and A. J. Campbell, ACS Appl. Mater. Interfaces, 2020, 12, 39471–39478.
13. Y. Yang, R. C. da Costa, M. J. Fuchter and A. J. Campbell, Nat. Photonics, 2013, 7, 634–638.
14. L. Wan, J. Wade, F. Salerno, O. Arteaga, B. Laidlaw, X. Wang, T. Penfold, M. J. Fuchter and A. J. Campbell, ACS Nano, 2019, 13, 8099–8105.
15. J. Wade, J. N. Hilfiker, J. R. Brandt, L. Liirò-Peluso, L. Wan, X. Shi, F. Salerno, S. T. J. Ryan, S. Schöche, O. Arteaga, T. Jávorfi, G. Siligardi, C. Wang, D. B. Amabilino, P. H. Beton, A. J. Campbell and M. J. Fuchter, Nat. Commun., 2020, 11, 1–11.
16. W. Shi, F. Salerno, M. D. Ward, A. Santana-Bonilla, J. Wade, X. Hou, T. Liu, T. J. S. Dennis, A. J. Campbell, K. E. Jelfs and M. J. Fuchter, Adv. Mater., 2021, 33, 2004115.
17. Y. Yang, B. Rice, X. Shi, J. R. Brandt, R. Correa Da Costa, G. J. Hedley, D. M. Smilgies, J. M. Frost, I. D. W. Samuel, A. Otero-De-La-Roza, E. R. Johnson, K. E. Jelfs, J. Nelson, A. J. Campbell and M. J. Fuchter, ACS Nano, 2017, 11, 8329–8338.

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