Nanocrystals explained through the Eye of the Fourier Transformation

Jour Fixe talk by Klaus Boldt on May 17, 2017

Klaus Boldt is a Research Fellow of the Zukunftskolleg affiliated with the Department of Chemistry.

Semiconductor nanocrystals are fascinating and highly promising materials for basic research as well as applications ranging from medical diagnosis to renewable energy production. Their key property is that they exhibit bright and stable fluorescence in colours that can be tuned by changing the particle size. This phenomenon can only be described using quantum mechanics and is one of very few examples in which these abstract physics can be demonstrated to our eyes in a tangible way. Albeit being stable fluorophores semiconductor nanocrystals are affected strongly by their surroundings and a number of processes that reduce their efficiency. These detrimental effects can be understood and countered using a very powerful mathematical tool, the Fourier transformation. In this presentation the Fourier transformation and its relevance to many every-day phenomena is explained at a number of examples. It is then used to explain and mitigate the processes that reduce the efficiency of nanocrystal fluorescence by coating the nanocrystals with a graded shell.