Regensburg 2025 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
HL: Fachverband Halbleiterphysik
HL 13: Heterostructures, Interfaces and Surfaces
HL 13.3: Talk
Monday, March 17, 2025, 17:15–17:30, H17
Simulation of charge and excitation dynamics across nanostructured organic-organic interfaces — •Giacomo Cotelli1,2, Engin Torun2, Stefano Gottardi2, and Anna Köhler1 — 1Soft Matter Optoelectronics (EP II), University of Bayreuth, Bayreuth 95440, Germany — 2Simbeyond B.V., Eindhoven, The Netherlands
The deposition of organic layers via solution processing may lead to rough interfaces or intermixed regions between layers. To investigate the impact of roughness at organic-organic interfaces on the performances of OLEDs, we performed 3D kinetic Monte Carlo simulations of symmetrical bi- and three-layer devices. Our results reveal that the macroscopic behaviour of a device can be significantly affected by the shape and size of roughness at the organic interfaces, influencing both charge and exciton dynamics.
Namely, we introduced interfaces with periodic corrugation and either triangular or rectangular cross-section. In presence of charge accumulation at an interface with triangular cross-section, bilayer devices exhibit strong inhomogeneity in the spatial distribution of charge carriers, excitons and excitonic losses. Comparison to a flat-interface device reveals an increment in current density by a factor from 2 to 103, depending on the height of the energy barrier at the interface. This current density boost was successfully applied to improve charge injection towards a central emissive layer (EML) in simulated three-layer devices; the size and configuration of the interfaces can also be leveraged to fine-tune the recombination zone inside the EML. Nevertheless, we raise our concerns in terms of increased local material degradation.
Keywords: Kinetic Monte Carlo; Organic Light Emitting devices; Simulation; Organic-organic interfaces