Charge transfer plays a central role in many photoinduced processes in physics, chemistry, and biology. It is also key to the photon-to-charge conversion process in organic photovoltaic (OPV) systems, which find more and more widespread use. Unlike their conventional inorganic counterparts, this class of photovoltaic systems compulsorily includes organic conjugated conductive molecules. The conjugated materials, usually used as an active layer in OPVs, are chemical structures which are coupled through the π-orbitals leading to a delocalization of charges over the bonds participating in the conjugation. Usage of the organic materials determines the strong and weak points of the OPVs. The main advantages of using organic molecules are potentially low production cost in large volumes and solution processability. In addition, OPVs are relatively flexible and lightweight, and are thus very convenient for portable applications. On the other hand, the main weakness concerns mainly the relatively low conversion efficiency (up-to-date around 12%), and limited photostability in comparison to their inorganic analogues. In this work, we present a number of studies dedicated to charge photogeneration and charge transfer processes in novel conjugated systems. We focus on revealing the charge photogeneration efficiency and clarifying the intermolecular (between different molecules) and intramolecular (within one molecule) charge transfer processes that form the crucial initial steps in the energy conversion process in OPV devices.
|Qualification||Doctor of Philosophy|
|Place of Publication||[Groningen]|
|Publication status||Published - 2015|