Annegret Glitzky, Matthias Liero
Grigor Nika (WIAS)
01.01.2019 – 31.12.2020
Charge transport in disordered organic semiconductors can be modeled at very different scales, ranging from density functional theory for molecules, master equation approaches for carrier dynamics to drift-diffusion equations, see e.g. . Transport properties are heavily influenced by temperature such that self-heating effects have a strong impact on the performance of e.g. organic solar cells and transistors [10,6]. Nonlinear phenomena like S-shaped current-voltage relations with regions of negative differential resistance occur. The interplay of self-heating and temperature activated hopping transport in combination with the heat balance results in spatially inhomogeneous current flow and temperature distribution in organic LEDs (OLEDs) [3,4]. Hence, models and simulations of the electrothermal interplay in multidimensional organic devices are required that are as accurate as necessary but computationally not too costly and have to work for complicated device structures.
The objective of the project is to develop a hybrid model for the electrothermal description of multi-dimensional structured organic devices by combining models for device substructures with different model complexity. The two main building blocks are (1.) the Energy-Drift-Diffusion (EDD) modeling of organic devices, where the interplay of charge and heat flow is described via a van Roosbroeck system adapted to organic semiconductors coupled to a heat equation with Joule and recombination heat sources (see [2,5]) and (2.) p(x)-Laplace thermistor (TH) models for organic semiconductor devices as introduced in . Within the project we aim to derive models of type (TH) as limit models from (EDD), formulate and investigate from an analytical point of view hybrid models with varying model complexity in the substructures of the devices including the transfer conditions at boundaries between device substructures, and finally discuss numerical approximations and implementation of hybrid models.
Please insert any kind of pictures (photos, diagramms, simulations, graphics) related to the project in the above right field (Image with Text), by choosing the green plus image on top of the text editor. (You will be directed to the media library where you can add new files.)
(We need pictures for a lot of purposes in different contexts, like posters, scientific reports, flyers, website,…
Please upload pictures that might be just nice to look at, illustrate, explain or summarize your work.)
As Title in the above form please add a copyright.
And please give a short description of the picture and the context in the above textbox.
Don’t forget to press the “Save changes” button at the bottom of the box.
If you want to add more pictures, please use the “clone”-button at the right top of the above grey box.