We work on the numerical simulation of opto-electronic semiconductor devices such as LEDs or solar cells. Here, we especially focus on light generation, propagation and absorption in such devices that typically feature elaborate nano-structures. To this end, we successfully developed the finite-element simulation software OPUS 3D. It is based on a novel mathematical approach - the Ultra-Weak Variational Formulation (UWVF) - and allows for an computationally efficient solution of the three-dimensional Maxwell equations on large domains. By additionally applying elaborate parallelzation schemes the software runs very efficiently on multi-core computers.
In a research project that was carried out in close collaboration with the Swiss Federal Laboratories for Materials Science and Technology Empa and the Swiss Federal Office of Energy BfE we could demonstrate that OPUS 3D very suitable for the design of solar cells. During this project we combined both numerical and experimental approaches for analyzing and designing thin-film solar cells. The most important outcomes of our research project are summarized in this article.