Structural and Spectroscopic Investigation of Nanomorphology in Bulk Heterojunction Organic Solar Cells

This thesis focuses on organic solar cells (OSCs) which are photovoltaic devices where the active layer is based on organic semiconductors. OSCs have recently demonstrated a record efficiency of over 19% and offer advantages such as easy processing, semitransparency, and flexibility. Niche applications include building integrated photovoltaics and indoor photovoltaics. The efficiency of OSCs is highly dependent on the bulk heterojunction (BHJ) morphology, which is formed by mixing organic semiconducting materials and is easily modulated by varying processing parameters. Here, the BHJ morphology is visualized by various structural and spectroscopic techniques to understand the structure-function relationship and improve OSC performance.