In 1995 the leading British materials chemist Paul O’Brien, who has died aged 64 after suffering from brain cancer, began to use chemical synthesis to make quantum dots, which are tiny semiconductor particles, only nanometres across, that can be made to emit light of varying colours according to their size. Up to that point quantum dots had been difficult to produce, requiring the use of hazardous metal alkyl precursors at high temperatures. O’Brien’s new method not only allowed them to be mass-produced; it also required much less energy and generated fewer harmful byproducts.
As a consequence, quantum dots are now ubiquitous in modern electronics and are used in any number of applications, from lighting and visual display units to solar energy capture and bio-markers, which help doctors to detect disease in the human body.
O’Brien’s work on this branch of nanoscience, dealing with materials that are typically thousands of times smaller than the width of a human hair, was revealed to the world in a 1996 paper in the journal Advanced Materials, and was a key discovery in its field. Thereafter he concentrated on the real-world impact of his work, producing a number of patents based on the process and, in 2001, establishing a company, Nanoco Technologies, which supplies quantum dots to global businesses such as Dow, Wah Hong Co and Merck.
A native of Manchester, Paul was born in Ancoats and brought up in Collyhurst and Failsworth. He was the son of Thomas, an engineer at the electrical engineering firm Ferranti, and Maureen (nee Graham), a clerk at a raincoat factory. From Cardinal Langley grammar school in Middleton he went to the University of Liverpool, where he gained a degree in chemistry, and to University College Cardiff for his PhD studies on the binding of metals to amino acids.
In 1978 he became a lecturer at Chelsea College of Science and Technology in London, and six years later moved to Queen Mary College, London (now Queen Mary University of London), where he spent 11 years, latterly as a professor, developing the materials chemistry activity for which he is celebrated. His insights at the time, he always stressed, were highly influenced by discussions with a colleague at Queen Mary, Donald Bradley, who was using a similar approach to making other inorganic materials.
In 1995 he became professor of materials science at Imperial College London, and in 1999 moved to the University of Manchester to a joint professorship between Victoria University of Manchester school of chemistry and the Materials Science Centre jointly run by Victoria University of Manchester and Umist. During this time he also acted as associate dean for research and, from 2002, head of the department of chemistry, playing a key role in bringing together departments during the merger of Victoria University of Manchester with Umist.
He was head of the school of chemistry that resulted from the merger, and then head of the school of materials (2011-15). His common sense and immense patience proved invaluable in breaking down barriers between groups that had, until the merger, been in competing institutions.
O’Brien retired in July 2018 after his diagnosis, and approached his illness with his usual scientific curiosity and optimism, drafting and editing papers from his hospital bed, which he turned into an impromptu office. He published more than 700 scientific papers across his career and helped more than 100 young researchers obtain PhDs under his watchful eye, many of them scientists from developing countries.
He was passionate about science in Africa, and his advocacy and leadership in that sphere led to the procurement of significant amounts of funding from the Royal Society and the UK government for new materials for solar energy capture in three African countries. Elected a fellow of the Royal Society in 2013 and a fellow of the Royal Academy of Engineering in 2016, he was appointed CBE in 2016.
A wonderful raconteur who was generous with his time and energy – and who amused everyone with his unique emailing style, which varied from minimalist to poetic – he somehow found time outside his scientific work for many other interests, including reading, hill-walking and camping, theatre and football.
He is survived by his wife, Kym (nee Evans), whom he met while studying in Cardiff and married in 1979.
• Paul O’Brien, scientist, born 22 January 1954; died 16 October 2018
• This article was corrected on 18 December 2018. The original said that Paul O’Brien was born in Collyhurst, Oldham, but they are separate areas. He was born in Ancoats, Manchester, and brought up in Collyhurst and Failsworth.
