High-frequency EPR and ENDOR spectroscopy of Mn²+ ions in CdSe/CdMnS nanoplatelets

• Main Authors: Babunts, Roman A., Uspenskaya, Yulia A., Romanov, Nikolai G., Orlinskii, Sergei B., Mamin, Georgy V., Shornikova, Elena V., Yakovlev, Dmitri R., Bayer, Manfred, Isik, Furkan, Shendre, Sushant, Delikanli, Savas, Demir, Hilmi Volkan, Baranov, Pavel G.
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2023
• Subjects: Engineering::Materials::Photonics and optoelectronics materials; Colloidal Nanocrystals; CdSe Nanoplatelets
• Online Access: https://hdl.handle.net/10356/166027
• Institution: Nanyang Technological University

Semiconductor colloidal nanoplatelets based of CdSe have excellent optical properties. Their magneto-optical and spin-dependent properties can be greatly modified by implementing magnetic Mn2+ ions, using concepts well established for diluted magnetic semiconductors. A variety of magnetic resonance techniques based on high-frequency (94 GHz) electron paramagnetic resonance in continuous wave and pulsed mode were used to get detailed information on the spin structure and spin dynamics of Mn2+ ions in core/shell CdSe/(Cd,Mn)S nanoplatelets. We observed two sets of resonances assigned to the Mn2+ ions inside the shell and at the nanoplatelet surface. The surface Mn demonstrates a considerably longer spin dynamics than the inner Mn due to lower amount of surrounding Mn2+ ions. The interaction between surface Mn2+ ions and 1H nuclei belonging to oleic acid ligands is measured by means of electron nuclear double resonance. This allowed us to estimate the distances between the Mn2+ ions and 1H nuclei, which equal to 0.31 ± 0.04, 0.44 ± 0.09, and more than 0.53 nm. This study shows that the Mn2+ ions can serve as atomic-size probes for studying the ligand attachment to the nanoplatelet surface.