Back to overview

Microscopic Theory of Cation Exchange in CdSe Nanocrystals

Type of publication Peer-reviewed
Publikationsform Original article (peer-reviewed)
Author Ott Florian D., Spiegel Leo L., Norris David J., Erwin Steven C.,
Project Electronic Impurity Doping of Semiconductor Nanocrystals
Show all

Original article (peer-reviewed)

Volume (Issue) 113(15)
Page(s) 156803
Title of proceedings PHYSICAL REVIEW LETTERS
DOI 10.1103/physrevlett.113.156803


Although poorly understood, cation-exchange reactions are increasingly used to dope or transform colloidal semiconductor nanocrystals (quantum dots). We use 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.