Size-Dependent Lattice Dynamics of Atomically Precise Cadmium Selenide Quantum Dots.

Autor:	Shi C; Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, USA., Beecher AN; Department of Chemistry, Columbia University, New York, New York 10027, USA., Li Y; American Physical Society, 1 Research Road, Ridge, New York 11961, USA., Owen JS; Department of Chemistry, Columbia University, New York, New York 10027, USA., Leu BM; Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA.; Department of Physics, Miami University, Oxford, Ohio 45056, USA., Said AH; Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA., Hu MY; Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA., Billinge SJL; Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, USA.; Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA.
Jazyk:	angličtina
Zdroj:	Physical review letters [Phys Rev Lett] 2019 Jan 18; Vol. 122 (2), pp. 026101.
DOI:	10.1103/PhysRevLett.122.026101
Abstrakt:	Material properties depend sensitively on the atomic arrangements and atomic bonding, but these are notoriously difficult to measure in nanosized atomic clusters due to the small size of the objects and the challenge of obtaining bulk samples of identical clusters. Here, we have combined the recent ability to make gram quantities of identical semiconductor quantum-dot nanoparticles with the ability to measure lattice dynamics on small sample quantities of hydrogenated materials using high energy resolution inelastic x-ray scattering, to measure the size dependence of the phonon density of states in CdSe quantum dots. The fact that we have atomically precise structural models for these nanoparticles allows the calculation of the phonon density of states using density functional theory, providing both experimental and theoretical confirmations of the important role that the inertia of the surface capping species plays on determining the lattice dynamics.
Databáze:	MEDLINE
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