Light-Induced Paramagnetism in Colloidal Ag+‑Doped CdSe Nanoplatelets

• Published in: The journal of physical chemistry letters Vol. 12; no. 11; pp. 2892 - 2899
• Main Authors: Najafi, Arman, Sharma, Manoj, Delikanli, Savas, Bhattacharya, Arinjoy, Murphy, Joseph R, Pientka, James, Sharma, Ashma, Quinn, Alexander P, Erdem, Onur, Kattel, Subash, Kelestemur, Yusuf, Kovalenko, Maksym V, Rice, William D, Demir, Hilmi Volkan, Petrou, Athos
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 25-03-2021
• Subjects: Physical Insights into Light Interacting with Matter
• ISSN: 1948-7185; 1948-7185
• DOI: 10.1021/acs.jpclett.1c00398

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 (P X ) and the exciton Zeeman splitting (ΔE Z ) were recorded as a function of the magnetic field (B) and temperature (T). Both ΔE Z and P X have a Brillouin-function-like dependence on B and T, 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 Ag2+, 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.