Efficiently Harvesting Singlet and Triplet Excitations in Organic Materials – STROM
Electroluminescence is the phenomenon defining light emission generated by a system in response to an applied voltage - that generates a current (Strom, in German) in the system. In our everyday life we observe often examples of electroluminescence, in light emitting diodes (LEDs) and in organic LEDs (OLEDs), used for artificial lightning and displays. Exploiting electroluminescence in organic materials for applications in OLED technology promises to be an efficient, low-cost, and clean source of artificial lightning. However, large-scale commercialization of OLEDs still requires studies on their operating principles, which are currently carried out both at the academic and industrial levels.
Despite an increasing effort has been devoted to this topic over the last few years, theoretical and computational modelling of electroluminescence in organic materials has failed to provide a satisfactorily general picture of the microscopic processes at play. STROM will remedy to this lack of first-principle information on the phenomenon of electroluminescence, by tackling the problem in organic materials manifesting thermally-activated delayed fluorescence (TADF). Third-generation OLED are based on TADF, and promise to be able to harvest singlet and triplet excitations produced in the organic emitting layer by the application of the voltage for light emission.
STROM will unravel the key steps of the phenomenon of electroluminescence in organic TADF materials, by describing, based on first- principles, the processes of (i) electron-hole migration and exciton formation via the application of the voltage, (ii) triplet-to-singlet up-conversion yielding light emission via delayed fluorescence, (iii) the process of spontaneous emission via fluorescence. STROM will provide qualitative and quantitative understanding of the cascade of out-of-equilibrium processes taking place in the organic layer over length and time scales spanning several orders of magnitude.
Madame Federica Agostini (Institut de Chimie Physique)
The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.
ICP Institut de Chimie Physique
Help of the ANR 113,500 euros
Beginning and duration of the scientific project: May 2023 - 24 Months