Bringing Sensitive Circularly Polarized Luminescence Spectroscopy to the Time Domain

Materials capable of emitting circularly polarized light (CPL) are promising for breaking efficiency limits in existing optoelectronic applications and may enable entirely new photonic and spintronic technologies [1]. However, reliably detecting CPL with the necessary sensitivity to quantify low dissymmetry factors, while being able to identify and ideally circumvent artefacts arising from linear dichroism, linear birefringence or linearly polarized emitted or scattered light is experimentally challenging [2].<br/><br/>Here we report on our recent efforts to develop CPL detection with the additional dimension of time evolution to achieve broadband, calibration-free CPL spectroscopy with nanosecond time resolution [3]. This technique will serve as a powerful tool to study the dynamics of chiral emitters and to understand how chirality evolves in the excited state.<br/><br/>[1] Crassous, Fuchter, Freedman, Kotov, Moon, Beard, Feldmann, Nat. Rev. Mater. 8, 365 (2023).<br/>[2] Kitzmann, Freudenthal, Reponen, VanOrman, Feldmann, Adv. Mater. <i>in press</i> (2023).<br/>[3] Reponen <i>et al. to be submitted</i> (2023).