Gopal Dixit a and Adam Kirrander b
aDept. Physics, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
bSchool of Chemistry, University of Edinburgh, Edinburgh, EH9 3FJ, UK. E-mail:

Photo-induced processes are of great importance in the natural world and across science. Examples include the ultrafast process in vision, energy-release by water-splitting in photosynthesis, chemical reactions in the atmosphere, photocatalysis, and technologies such as petahertz electronics, photovoltaics, and light-emitting diodes. Due to their intrinsic complexity and ultrafast nature, photo-induced processes remain among the least understood types of physical and chemical processes. New experimental techniques, capable of unprecedented temporal and spatial resolution, offer transformative opportunities for new and improved understanding. These developments are driven by the appearance of free-electron lasers, new sources of pulsed electrons, table-top based attosecond laser sources, advanced detection techniques, and other existing and emerging experimental techniques. A large and important contribution is made by advances in theory and computational modelling, including quantum molecular dynamics simulations, methods to interpret and analyse experiments, and theoretical advances that guide new and emerging experimental approaches.

This Discussion follows Faraday Discussions 171 (2014) and 194 (2016). Looking at these two previous meetings, the rate of progress in this field is astounding. Facility based experiments, which were at an early stage in 2014, now form a large component of new science in this area. Some emergent trends at the meeting in 2016, such as the combination of complementary observables to gain greater understanding, are continuing to grow, while new trends in evidence at the current meeting include machine learning, advanced data analysis, and sophisticated methods for the interpretation of experimental data. The format of Faraday Discussions is ideal for complex and wide-ranging topics. It is our hope that this meeting provided a much-needed opportunity for critical discussion of technical and scientific advances, challenges and opportunities, and will inspire the research agenda for years to come.


The organisation of this meeting would not have been possible without the expert help of staff at the Royal Society of Chemistry, and we would like to thank Marie Cote, Heather Montgomery, Claire Springett, Vikki Pritchard, Danny Andrews, and Helen Lunn. The Chairs, Adam Kirrander and Gopal Dixit, had excellent support from the Scientific Committee: Russell Minns, Francesca Calegari, Tais Gorkhover, and Olga Smirnova. The session chairs were largely taken from the committee, with additional help from Linda Young gratefully acknowledged. The all-important opening and closing lectures were beautifully delivered by Toshinori Suzuki and Misha Ivanov. We thank the poster prize committee, Russell Minns, Francesca Calegari, Jochen Küpper, Kenneth Lopata, Jean Christophe Tremblay, Adi Natan, and Jon Marangos, for selecting the winners (Nicola Mayer and Maria Elena Castellani) among the many excellent posters. Finally, and most importantly, we sincerely thank all speakers and participants for making this such an exciting and stimulating meeting. Thank you.

This journal is © The Royal Society of Chemistry 2021