10.1021/jp4032749.s001
Yorai Amit
Yorai
Amit
Hagai Eshet
Hagai
Eshet
Adam Faust
Adam
Faust
Anitha Patllola
Anitha
Patllola
Eran Rabani
Eran
Rabani
Uri Banin
Uri
Banin
Anatoly I. Frenkel
Anatoly I.
Frenkel
Unraveling the Impurity Location and Binding in Heavily
Doped Semiconductor Nanocrystals: The Case of Cu in InAs Nanocrystals
American Chemical Society
2013
XAFS
Doped Semiconductor Nanocrystals
InAs NanocrystalsThe doping
InAs quantum dots
impurity
NC
DFT
doping levels
Cu
2013-07-03 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Unraveling_the_Impurity_Location_and_Binding_in_Heavily_Doped_Semiconductor_Nanocrystals_The_Case_of_Cu_in_InAs_Nanocrystals/2400121
The doping of colloidal semiconductor
nanocrystals (NCs) presents
an additional knob beyond size and shape for controlling the electronic
properties. An important problem for doping with aliovalent elements
is associated with resolving the location of the dopant and its structural
surrounding within small NCs, an issue directly connected with self-purification.
Here we used a postsynthesis diffusion-based doping method for introducing
Cu impurities into InAs quantum dots. X-ray absorption fine structure
(XAFS) spectroscopy experiments along with first-principle density
functional theory (DFT) calculations were used to probe the impurity
sites. The concentration dependence was investigated for a wide range
of doping levels, helping to derive a self-consistent picture where
the Cu impurity occupies an interstitial site within the InAs lattice.
Moreover, at extremely high doping levels, Cu–Cu interactions
are identified in the XAFS data. This structural model is supported
by X-ray diffraction data, along with the DFT calculation. These findings
establish the reproducibility of the diffusion-based doping strategy
giving rise to new opportunities of correlating the structural details
with emerging electronic properties in heavily doped NCs.