Microscopic Theory of Cation Exchange in CdSe Nanocrystals

Abstract

Although poorly understood, cation-exchange reactions are increasingly used to dope or transform colloidal semiconductor nanocrystals (quantum dots). We used density-functional theory and kinetic Monte Carlo simulations to develop a microscopic theory that explains structural, optical, and electronic changes observed experimentally in Ag-cation-exchanged CdSe nanocrystals. We find that Coulomb interactions, both between ionized impurities and with the polarized nanocrystal surface, play a key role in cation exchange. Our theory also resolves several experimental puzzles related to photoluminescence and electrical behavior in CdSe nanocrystals doped with Ag.

12 pages, 4 figures. Published in Physical Review Letters. Supplementary information is included as ancillary file. The movie can be downloaded from http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.113.156803

References in corpus (1)

• Heavily Doped Semiconductor Nanocrystal Quantum Dots

Cited by in corpus (2)

• Influence of the Ion Coordination Number on Cation Exchange Reactions with Copper Telluride Nanocrystals
• From Impurity Doping to Metallic Growth in Diffusion Doping: Properties and Structure of Ag Doped InAs Nanocrystals