Complexity of Electron Transport in Nanoscale Molecular Junctions

In this dissertation, we analyse the charge transport of nanoscale molecular junctions in mechanically controllable break junction (MCBJ) experiments. In particular, we focus on the characterization of molecular features going beyond the "single-peak" picture, that is, considering features in the measurements in addition to themost prominent one...

It's a Trap: Studying the quantum dot surface on an atomistic scale

Due to their size-dependent properties, high photoluminescence quantum yield and relatively cheap solution-based processing, colloidal quantum dots (QDs) are of great interest for application in optoelectronic devices. However, the efficiency of these devices is often limited by the presence of trap states: localized electronic states that lead...

Structural and Excited State Dynamics in Hybrid Halide Perovskites

During the last decade perovskite materials have rapidly emerged, and are currently among the most promising candidates as materials for solar cells and other opto-electronic applications. Although our knowledge related to these materials has advanced rapidly in last few years there are still many unknown aspects and many challenges remain....

Triplet Dynamics in Crystalline Perylene Diimides

Conjugated organic materials are interesting for application in opto-electronic devices where they can act as a light absorbing layer, for instance in solar cells or as a light emitting layer in light-emitting diodes. In addition, they can also be used as the semiconducting materials in for instance field-effect transistors. Conjugated organic...

Towards control of the optoelectronic properties of organic-inorganic perovskites

In this thesis we have aimed to tune and control the optoelectronic properties of organic-inorganic metal halide perovskites by systematically changing components in the structure and studying the charge carrier dynamic mechanisms....

Role of the organic cation in hybrid halide perovskites: A computational study

Hybrid halide perovskites are currently the most studied optoelectronic materials. They have been successfully employed as the active material in solar cells. Despite the achieved success of these materials, the properties of these hybrid frameworks of an inorganic lattice that includes organic cations are not fully understood. This is because...

Charge and Energy Transfer in Multichromophoric Arrays

In nature, solar energy conversion occurs with a process called photosynthesis. Although the overall energy efficiency of the storage of the energy of sunlight into biomass is low, the individual photophysical processes that occur have a high quantum yield. In the latter sense, natural photosynthesis can serve as a valuable inspiration for the...

Mechanism and Dynamics of Charge Transfer in Donor-Bridge-Acceptor Systems

Photoinduced charge transfer in organic materials is a fundamental process in various biological and technological areas. Donor-bridge-acceptor (DBA) molecules are used as model systems in numerous theoretical and experimental work to systematically study and unravel the underlying mechanisms of charge transfer. Despite the respectable successes...

Singlet Exciton Fission and Photochemical Upconversion

The Sun is the main source of renewable energy on Earth. Our planet receives about 174 PW of solar power. At the same time, global energy consumption from all energy sources is orders of magnitude lower and is equal to approximately 16 TW. Clearly, solar energy has a tremendous potential, as well as numerous advantages over conventional sources...