Researchers at Kyushu University have developed an analytical model that details the kinetics of the exciton dynamics in OLED materials. The findings could enhance the lifetime of OLED devices and accelerate the development of more advanced and efficient materials. OLEDs light up because of excitons; when you add energy into atoms, their electrons get excited and jump to a higher energy state. When they come back down to their regular energy state, they produce fluorescence. Excitons can also go into different states, namely a singlet state, denoted as S1, or a triplet state, denoted as T1. Fluorescence can only happen when excitons drop from the singlet state. Understanding the gap between S1 and T1 in thermally activated delayed fluorescence (TADF) materials is fundamental in both evaluating the efficiency of OLED materials and testing the efficacy of new materials. Excitonic energy configuration changes of a thermally activated delayed fluorescence material. Courtesy of Kyushu University “When developing new TADF materials we employ quantum calculations to forecast this gap, denoted as ΔEst. However, it’s not feasible to theoretically calculate the behavior of all electrons to determine the accurate excitation state configuration," said research associate professor Youichi Tsuchiya, one of the authors of the study describing the advancement. "So, to reduce computation costs we usually work with certain assumptions. But this results in different values between experimental and estimated data,” Using fundamental theories of physical chemistry and taking into account the exciton transfer between the triplet energy states, the research team developed a model that can more accurately estimate ΔEs. The team expressed future utilization of their analytical method on other types of TADF materials to clarify exciton dynamics in OLED research. In future research, they want to use AI to accurately predict the properties of new materials. The research was published in Nature Communications (www.doi.org/10.1038/s41467-025-59910-z)