Sebastian had the opportunity to contribute a chapter on Charge Recombination in Organic Solar Cells to the book Soft-Matter Thin Film Solar Cells: Physical Processes and Device Simulation that was recently published online and in print by AIP Publishing. The chapter provides a broad overview of different recombination mechanisms and is divided into the parts Geminate recombination, Non-geminate recombination in the bulk, and Recombination at the contacts.
The chapter is aimed at graduate students, PhD candidates and postdocs who want to learn about elementary processes in organic solar cells. Special emphasis is placed on the latest findings from the literature, especially on state-of-the-art non-fullerene based blend systems.

Contents of the book chapter:
- Introduction
- Geminate recombination
- The Onsager-Braun model and its limitations
- Delocalization, disorder, and energy bending
- Experiments to monitor geminate recombination
- Non-geminate recombination in the bulk
- Langevin recombination and beyond
- Effect of phase separation
- Non-encounter-limited recombination
- Charge carrier trapping
- Consequences of non-geminate recombination from a device perspective
- Recombination at the contacts
- Selective and non-selective contacts
- Extraction barrier
Reference:
S. Wilken, Charge recombination in organic solar cells, in Ren, J. and Kan, Z. (eds.), Soft-Matter Thin Film Solar Cells: Physical Processes and Device Simulation, Melville, New York: AIP Publishing (2020)