Advanced electrical and optical characterization of recombination in organic solar cells

The research and development of organic solar cells is driven by the desire for cheap and sustainable renewable energy sources. While promising progress in cell efficiency has been achieved in recent years, there are still open questions about device physics and fundamental limitations of the performance of this arising technology. This work investigates the recombination and energetics of photogenerated charge carriers and the resulting open circuit voltage in polymer based organic solar cells by charge extraction and temperature dependent measurements. The applicability and limitations of transient characterization techniques commonly used in the field of organic photovoltaics are elaborated. In addition, recombination at electrode interfaces and the impact of thin film optics on luminescence spectra are studied and described in detail leading to a more comprehensive understanding of device physics governing the characterization of organic solar cells.