Novel chiroptical probes to track spin & light polarization in space & time in emerging semiconductors

Solution-processable semiconductors like halide perovskites and certain molecules are promising for next-generation spin-optoelectronic applications [1]. Yet, we don’t fully understand what governs spin and light polarization in these materials, and even less how these are affected by chirality.[2] In this talk, I will give an overview of our recent efforts to understand the spin-optoelectronic performance of these materials through time-, space- and polarization-resolved spectroscopy and microscopy. For investigating halide perovskite films, we pushed broadband circular dichroism to diffraction-limited spatial and 15 fs time resolution for creating a spin cinematography technique to witness the ultrafast formation of spin domains due to local symmetry breaking and spin-momentum locking [3]. I will then briefly explain the fundamentals and artefacts involved in measuring circularly polarized luminescence reliably and introduce an open-access methodology and code to do so [4]. Finally, I will show our most recent development of a transient sensitive broadband full Stokes-vector spectroscopy with unprecedented time- and polarization resolution to track the emergence of chiral light emission [5]. [1] Nature Reviews Materials 8, 365 (2023); [2] Nature Reviews Chemistry, in press (2024/25); [3] Nature Materials 22, 977 (2023); [4] Advanced Materials 35, 2302279 (2023); [5] unpublished (2024/25).