On September 30, 2021, Professor Ma Yuguang, Director of the State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, was invited to give an academic lecture to 2020 ISAM students, with the theme of “Fundamental Science of Organic Electroluminescent Materials”.
Professor Ma first mentioned some challenges of technological development faced by China and he called on that we should see the shortage of scientific research in China and be always curious about pursuing the truth and exploring the nature. Then, Professor Ma told us to distinguish the frontiers of science and the fundamentals of science. The former one is like the seashore, where the footprints are easy to leave, but also easy to be erased by the tide. However, the fundamentals of science is as solid as Mount Everest, which is based on previous studies. Professor Ma called for more attention to the fundamentals of science and the exploration of the development of fundamental problems in science.
Next, Professor Ma talked about the development history, basic theories, and research directions of luminescent materials in recent years, as well as some existed problems and solutions in practice of luminescence science. Professor Ma pointed out that luminescence science originates from the understanding of the nature of spectrum, in which energy is the essential factor. Changes in the state of matter correspond to energy, and some of these pathways are accompanied by luminescence, which is part of luminescence science. Furthermore, the electron excitation model was established by using the electron transition spin law, which is related to the luminous efficiency and lifetime of luminescent materials.
On this basis, Professor Ma introduced his researches, such as the transformation between single-line and triple-line, the improvement of phosphorescence intensity, and how to solve the problem of ultra-fast transformation between excited states. He stressed that students should work hard on the study of basic disciplines and lay a solid foundation for future research.
Professor Ma then explained principles of OLED, and put forward his own views on the solution of practical problems. The first one is to replace the traditional CT state materials with high-energy and low-cost excited-state materials, and achieve high efficiency of luminescence through TS energy conversion. The second one is about spectral regulation, that is, to narrow the spectrum of OLED materials. Professor Ma told the students that low-frequency vibration mode is dominant in favor of spectral narrowing, and the material molecule needs to be partially flexible to improve the stability of materials.
After the lecture, the students visited the exhibition room and laboratories in the State Key Laboratory of Luminescent Materials and Devices, where they have seen abundant achievements made by researchers of the State Key Lab, and advanced intruments and equipment like the spectrograph, the nuclear magnetic resonance instrument, the equipment for ultrafast optics and others. The talk and the visit have opened students’ horizon and helped them find the fields that they are interested in.
