Magnus B. Fridriksson

My name is Magnus and I come from Iceland. I moved to the Netherlands in the fall of 2014 to do my master in chemical engineering at TU Delft and subsequently started my Ph.D. in October 2016 with Ferdinand Grozema. My research topic is excited states in organic semiconductors and in my research I utilize both ultrafast spectroscopy as well as computational methods to investigate these excited states.

Organic semiconductors are conjugated molecules or polymers containing mostly carbons and hydrogens. They are considered as one of the possible alternatives to silicon for solar cells applications. Their photoconversion process is however different compared to silicon. In silicon an absorbed photon results in formation of a free electron (-) and a free hole (+) which can then be directly extracted. In organic solar cells the electron and hole formed are not free but bound together. They therefore have to be separated from one another before they can be extracted. Because of this difference it is important to understand the behavior of the excited state in organic semiconductors in order to have a better possibility in the future of making high efficiency organic solar cells.

Ultrafast spectroscopy is ideal to investigate these excited states as they often have very short lifetime. In my research I, for instance, utilize femtosecond transient absorption spectroscopy. There the change in absorption after excitation is measured in the timescale of few femtoseconds to 3 nanoseconds. This gives interesting information on both the lifetime of the excited state as well as how it evolves through time.