Speakers

Prof. Donal Bradley’s pioneering research covers many aspects of the fundamental understanding and development of soluble semiconductor materials, especially fluorene-based polymers, for device applications and has been recognized by numerous prizes and awards, including the E-MRS Jan Czochralski Award, IET Faraday Medal, Royal Society Bakerian Medal, IOP Faraday Medal, and SID Jan Rajchman Prize. His publications have received more than 94,000 Google Scholar citations (h-index = 134) placing him among the 0.05% most-cited applied physicists in the world.  In addition, Professor Bradley has worked closely with industry to translate the outcomes of his research into technologies and is a co-founder of spinout companies Cambridge Display Technology, Molecular Vision and PeroLED, having also worked closely with Sunew and Solar Press in advisory/Board roles.  He is a Commander of the Order of the British Empire, Fellow of the Royal Society and the US National Academy of Inventors, received a DSc honoris causa from the Hong Kong Baptist University and delivered the 2009 Chau Wai Yin Memorial Lecture at Hong Kong Polytechnic University.

Development of Fluorene-based Materials for Device Applications

Abstract

In this Plenary Lecture I will describe research focused on developing an understanding of the underlying physics of fluorene-based systems and their potential for device applications.  I will describe the control of device-relevant properties, with an emphasis on physical structure tuning through conformation and orientation.  Examples will be provided in relation to LEDs, microcavities and lasers, with (i) conformation used to define optical structures,^[1] optimize charge injection and transport,^[2] luminescence efficiency,^[3] colour saturation,^[4] triplet diffusion,^[5] nonlinear optical response^[6] and polariton emission^[7] and (ii) orientation to define optical structures,^[8] generate highly polarized emission,^[9]enhance oscillator strength for cavity exciton – photon coupling^[10] and reduce polariton lasing thresholds. ^[11]   

^[1] A. Perevedentsev, Y. Sonnefraud, S. Sharma, A.E.G. Cass, S.A. Maier, J.S. Kim, P.N. Stavrinou, D.D.C. Bradley, Nat. Commun. 6 (2015), 5977.

^[2] B. Wang, H. Ye, M. Riede, D.D.C. Bradley, ACS Appl. Mater. Interfaces 13 (2021), 2919-2931.

^[3] M. Ariu, D.G. Lidzey, M. Sims, A.J. Cadby, P.A. Lane and D.D.C. Bradley J.Phys.Condens.Matter 14 (2002), 9975-9986; A. Perevedentsev, N. Chander,  J.-S. Kim, D.D.C. Bradley, Journal of Polymer Science, Part B: Polymer Physics 54 (2016), 1995-2006.

^[4] I. Hamilton, N. Chander, N.J. Cheetham, M. Suh, M. Dyson, X. Wang, P.N. Stavrinou, M. Cass, D.D.C. Bradley, J.-S. Kim, ACS Appl. Mater. Interfaces 10 (2018), 11070-11082.

^[5] N.T. Lambeva, C. Mullen, X. Gao, R.A. Taylor, Y. Tao, D.D.C. Bradley, (2022), at press.

^[6] A.J. Cadby, P.A. Lane, H. Mellor, S.J. Martin, M. Grell, C. Giebeler, D.D.C. Bradley, M. Wohlgenannt, C. An and Z.V. Vardeny, Phys. Rev. B 62 (2000), 15604-15609; T. Virgili, D. Marinotto, G. Lanzani, D.D.C. Bradley, Appl. Phys. Lett. 86 (2005), 091113.

^[7] F. Le Roux, D.D.C. Bradley, Phys. Rev. B 98 (2018), 195306.

^[8] Y. Shi, P.S. Salter, M. Li, R.A. Taylor, S.J. Elston, S.M. Morris, D.D.C. Bradley, (2020), Adv. Funct. Mater. (2020) 2007493.

^[9] K.S. Whitehead, M. Grell, D.D.C. Bradley, M. Jandke and P. Strohriegl, Appl. Phys. Lett. 76 (2000), 2946-2948; T. Virgili, D.G. Lidzey, M. Grell, S. Walker, A. Asimakis and D.D.C. Bradley, Chem. Phys. Lett. 341 (2001), 219-224.

^[10] F. Le Roux, R.A. Taylor, D.D.C. Bradley, ACS Photonics 7 (2020), 746-758.

^[11] F. Le Roux, A. Mischok, D.D.C. Bradley, M.C. Gather (2022), submitted. (arXiv: 2202.10417).