Organic semiconductors are an emerging class of materials for opto-electronic devices such as solar cells and organic light emitting diodes. As a result, it's important to tune materials properties for specific requirements like efficient light absorption and emission, long excited state lifetimes, or more exotic properties (such as singlet fission). One of the advantages of these organic semiconductors over conventional inorganic semiconductors is that by changing the design of the molecules many different properties can be generated. For his Ph.D. research, Anton Berghuis explored changing materials properties using light.