caa a22 4500 530097621 20200323030318.0 cr unu---uuuuu 181026e20180926xx s 000 0 eng 10.3929/ethz-b-000290558 doi 10.1021/acscentsci.8b00196 doi (ETHRESEARCH)oai:www.research-collection.ethz.ch:20.500.11850/290558 Resolving the Core and the Surface of CdSe Quantum Dots and Nanoplatelets Using Dynamic Nuclear Polarization Enhanced PASS-PIETA NMR Spectroscopy [Elektronische Daten] [Laura Piveteau, Ta-Chung Ong, Brennan J. Walder, Dmitry N. Dirin, Daniele Moscheni, Barbara Schneider, Janine Bär, Loredana Protesescu, Norberto Masciocchi, Antonietta Guagliardi, Lyndon Emsley, Christophe; id_orcid 0000-0001-9660-3890 Copéret, Maksym V. Kovalenko] Open access ethresearch Understanding the surface of semiconductor nanocrystals (NCs) prepared using colloidal methods is a long-standing goal of paramount importance for all their potential optoelectronic applications, which remains unsolved largely because of the lack of site-specific physical techniques. Here, we show that multidimensional 113Cd dynamic nuclear polarization (DNP) enhanced NMR spectroscopy allows the resolution of signals originating from different atomic and magnetic surroundings in the NC cores and at the surfaces. This enables the determination of the structural perfection, and differentiation between the surface and core atoms in all major forms of size- and shape-engineered CdSe NCs: irregularly faceted quantum dots (QDs) and atomically flat nanoplatelets, including both dominant polymorphs (zinc-blende and wurtzite) and their epitaxial nanoheterostructures (CdSe/CdS core/shell quantum dots and CdSe/CdS core/crown nanoplatelets), as well as magic-sized CdSe clusters. Assignments of the NMR signals to specific crystal facets of oleate-terminated ZB structured CdSe NCs are proposed. Significantly, we discover far greater atomistic complexity of the surface structure and the species distribution in wurtzite as compared to zinc-blende CdSe QDs, despite an apparently identical optical quality of both QD polymorphs. In Copyright - Non-Commercial Use Permitted http://rightsstatements.org/page/InC-NC/1.0 ethresearch Piveteau Laura joint author Ong Ta-Chung joint author Walder Brennan J. joint author Dirin Dmitry N. joint author Moscheni Daniele joint author Schneider Barbara joint author Bär Janine joint author Protesescu Loredana joint author Masciocchi Norberto joint author Guagliardi Antonietta joint author Emsley Lyndon joint author Copéret Christophe; id_orcid 0000-0001-9660-3890 joint author Kovalenko Maksym V. joint author ACS Central Science Washington, DC : American Chemical Society 4 (9), pp. 1113-1125 2374-7951 http://hdl.handle.net/20.500.11850/290558 text/html WWW-Backlink auf das Repository (Open access) 1 Journal Article ethresearch ETHRESEARCH 856 40 http://hdl.handle.net/20.500.11850/290558 text/html WWW-Backlink auf das Repository (Open access) ETHRESEARCH 700 1- Piveteau Laura joint author ETHRESEARCH 700 1- Ong Ta-Chung joint author ETHRESEARCH 700 1- Walder Brennan J. joint author ETHRESEARCH 700 1- Dirin Dmitry N. joint author ETHRESEARCH 700 1- Moscheni Daniele joint author ETHRESEARCH 700 1- Schneider Barbara joint author ETHRESEARCH 700 1- Bär Janine joint author ETHRESEARCH 700 1- Protesescu Loredana joint author ETHRESEARCH 700 1- Masciocchi Norberto joint author ETHRESEARCH 700 1- Guagliardi Antonietta joint author ETHRESEARCH 700 1- Emsley Lyndon joint author ETHRESEARCH 700 1- Copéret Christophe; id_orcid 0000-0001-9660-3890 joint author ETHRESEARCH 700 1- Kovalenko Maksym V. joint author ETHRESEARCH 773 0- ACS Central Science Washington, DC : American Chemical Society 4 (9), pp. 1113-1125 2374-7951 BK010053 XK010053 XK010000 ETHRESEARCH ETHRESEARCH ETHRESEARCH Journal Article Open access