����Vlog�ٷ� Cambridge: Dr Robert Westbrook

Position Governing Body Fellow Junior Research Fellow
School Department of Physics - The Cavendish Laboratory Department of Chemical Engineering and Biotechnology
Email rw794@cam.ac.uk

Rob is a Marie Skłodowska-Curie Postdoctoral Fellow in the Department of Chemical Engineering & Biotechnology and the Cavendish Laboratory. His on-going research focuses on using different types of microscopy to develop next-generation semiconductors for broad applications across optoelectronics.

Rob studied for his MSci in Chemistry & Molecular Physics at the University of Nottingham and carried out the research leg of his Master's at the University of Copenhagen, where he developed graphene derivatives for applications in transparent conductors. He received the King Memorial Prize for Outstanding Contribution to Research for his master's research. He then conducted his doctoral studies between University College London and Imperial via the Centre for Doctoral Training in Advanced Characterization of Materials, using advanced spectroscopy techniques to develop next-generation hybrid organic-inorganic solar cells. He was a Mistletoe Postdoctoral Fellow at the University of Washington under Professor David Ginger, where he used ultrafast spectroscopy to understand the role of solid-state packing in determining charge generation and air-sensitivity in organic semiconductors.

As a Marie Skłodowska-Curie Postdoctoral Fellow, his research aims to provide a better understanding of how nanoscale defects in emerging semiconductors impact the performance of solar cells, light-emitting diodes and transistors, using a mixture of spectroscopy, microscopy, and synchrotron X-ray characterization.

Control over conductivity and carrier type defines semiconductors. A general approach to increase carrier concentrations is doping, where a host atom is substituted for a lower (or higher) valence dopant atom, releasing a free electron (or positively charged hole). Indeed, high-performance commercial semiconductors based on first-generation semiconductors are often heavily doped. However, controlled doping of third-generation PSCs remains underdeveloped, most likely because traditional exogeneous methods for doping would likely cause severe damage to the relatively soft perovskite structure. On the other hand, perovskites containing Sn are known to undergo strong self p-doping (i.e. endogeneous), with high doping levels. This Sn redox chemistry in Sn-containing perovskites presents a potential lever for controlled doping.

Rob uses the world-class facilities at StranksLab and the Cavendish Laboratory to map the dopant density on the nanoscale in halide perovskites. He will then correlate this information with other types of microscopy (e.g. atomic force, X-ray), to establish deep relationships between local dopant density, morphology, crystal structure, and elemental composition. In doing so, Rob hopes to advance the performance of solar cells, LEDs, and field-effect transistors based on halide perovskites

Away from the laboratory, Rob enjoys spreading the word about optoelectronics to the broader public, leading outreach activities on making solar cells out of berries, explaining the role of the "band gap" in semiconductor science, and writing articles on exciting new research for Physics World.