26-01-2022: Talk by Dr. S. Kahmann

On January 26th, Simon Kahmann a Postdoc in Prof. S. Stranks’s lab at the University of Cambridge (UK) will present his talk on :
Taking a closer look: the power of optical microscopy to unravel the complex world of two-dimensional perovskites.

Studied since the 1980’s, research on two-dimensional perovskites has only recently exploded in the shadow of their 3D counterparts. Now, these compounds are studied for improved performance and stability of solar cells, light-emitting devices, scintillators, gas detectors, and many more applications. As a consequence of their two-dimensional nature, they are also prime candidates for studying fundamental exciton physics.
Liberated from the tight constraints of the Goldschmidt tolerance factor, the field produces an ever-growing library of potential spacer cations. Whereas early work was mostly based on simple primary amines with alkyl chains or a benzene ring, current efforts include heteroatoms, complex aromatic systems, chiral molecules, and bifunctional spacers.
I shall introduce some of the interesting aspects of 2D perovskites beyond their use in PV applications. In particular, I shall address currently debated topics regarding their bright luminescence: what is the origin of broad emission bands? Is Kasha’s rule broken? And what’s the matter with Dion-Jacobson compounds?
Besides such fundamental questions, I’ll use these studies to illustrate the power of optical microscopy experiments for research in energy materials – be they low-dimensional, perovskites, or organic.