Device Performance and Charge Carrier Dynamics in Organic Solar Cells: The Impact of Donor Polymer Properties and Morphology

Organic photovoltaic (OPV) technology has a potential advantage over inorganic photovoltaics because of low fabrication cost and mass production through roll-to-roll or injects printing techniques. In the recent years, OPV technology has reached efficiencies more than 13%, making it a viable candidate for future energy production. The performance of the organic solar cells strongly depends on the morphology of the active layer and properties of the donor polymer like regioregularity, and molecular weight. This thesis is devoted to understanding the role of poly(3-hexylthiophene) polymer regioregularity and molecular weight on the device performance, morphology and charge carrier dynamics inside the device. In addition to this, the influence of bulk morphology and domain purity on charge carrier recombination is also investigated in detail using various X-ray synchrotron and transient photovoltaic measurement techniques in high performance low bandgap OPV devices.