Light-Induced Paramagnetism in Colloidal Ag-Doped CdSe Nanoplatelets.

We describe a study of the magneto-optical properties of Ag-doped CdSe colloidal nanoplatelets (NPLs) that were grown using a novel doping technique. In this work, we used magnetic circularly polarized luminescence and magnetic circular dichroism spectroscopy to study light-induced magnetism for the first time in 2D solution-processed structures doped with nominally nonmagnetic Ag impurities. The excitonic circular polarization () and the exciton Zeeman splitting () were recorded as a function of the magnetic field () and temperature (). Both and have a Brillouin-function-like dependence on and , verifying the presence of paramagnetism in Ag-doped CdSe NPLs. The observed light-induced magnetism is attributed to the transformation of nonmagnetic Ag ions into Ag, which have a nonzero magnetic moment. This work points to the possibility of incorporating these nanoplatelets into spintronic devices, in which light can be used to control the spin injection.