Tom Gregorkiewicz received his MSc degree in experimental physics from Warsaw University. He then joined the Institute of Physics of the Polish Academy of Sciences, where he earned his PhD degree in 1980 with research on implantation defects in silicon. Afterwards, his work concentrated on magnetic resonance and optical spectroscopy of impurities in semiconductors. In 1985, he joined the University of Amsterdam where since 2003 he has held the professorial chair of Optoelectronic Materials. He is also a professor on personal title by nomination of the President of the Republic of Poland, and a visiting professor of the Osaka University (Japan) and Sungkyunkwan University (South Korea).

Tom’s scientific interests covered the optical properties of semiconductor nanostructures with an eye on possible applications in optoelectronics, photonics and photovoltaics. The primary focus of his work was on optical spectroscopy of nanostructured silicon. His group garnered great international recognition for their work on the physics behind the potential of efficiently harvesting and managing solar power using semiconductor nanocrystals (with over 20  publications throughout the years in various prestigious Nature Publishing Group journals). He was a leader in this field, both in the Dutch physics community and internationally. His highly successful research activities enjoy worldwide appreciation, both for their high scientific quality and for the application potential – witnessed from his increasing success in acquiring research funding from or in collaboration with industrial partners.

After officially reaching the retirement age, he actively chose to continue his research in order to realize his scientific dreams and ambitions with his thriving research group, from which he graduated a total of 21 PhD students, with several still ongoing. Tom was an inspiring researcher, mentor and teacher and possessed a great drive. This he used to the benefit of both his colleagues and students, with whom he was hugely popular. He set an example in never failing to take students seriously and challenging them to perform at their best. Tom was an open and sociable man and his group were treated part of his extended family. Tom’s enthusiasm in teaching and research will be sorely missed.