Fermer le menu



Xavier BLASE, TCM group, will present
NÉEL monthly seminar

Tuesday 12 April 2022 at 9:30

Meeting room N. Mott, D420 

Visio link : https://univ-grenoble-alpes-fr.zoom.us/j/92488235189?pwd=a2dra1VVcU90L0h3ZUtzU2xoaWN6Zz09


Title : Embedded many-body perturbation theory for the optoelectronic properties of large-scale disordered organic systems

Abstract :

Quantum formalisms designed to describe the properties (structural, electronic, conducting, etc.) of materials without any adjustable parameters remain challenging when it comes to addressing complex systems, where complexity may lie in the composition and structure or in the strength of the interactions. While mean-field density functional theory (1998 Chemistry Nobel prize ) provides impressive results for ground-state structural or vibrational properties, it is not designed to tackle electronic excitations. As an alternative, many-body perturbation theories have become a tool of choice in solid-state physics for studying the optoelectronic properties of crystals. Difficulties arise when attempting to explore with such techniques extended disordered systems : periodic boundary conditions cannot be used while the importance of long-range electrostatic and dielectric effects preclude the quantum chemistry approach of considering isolated molecules in the gas phase. We will present recent developments along the line of embedded, or QM/MM, formalisms allowing to perform accurate many-body calculations for the optoelectronic properties of organic systems immersed in complex electrostatic and dielectric environments. Applications to the study of the elusive doping mechanisms in organic semiconductors and to organic photovoltaics will be presented. These studies have been performed in the TCM group with major contributions from colleagues (Gabriele D’Avino, Simone Fratini), PhDs and postdocs (Jing Li, Paul Boulanger, Carina Faber, Massimiliano Comin, David Amblard) together with Ivan Duchemin at CEA/IRIG.