Doping-related
point defect engineering in low-dimensional semiconductor
nanostructures is important to regulate their optical and electronic
properties. The substitutional or interstitial location of heterovalent
dopants is critical and has not been controlled effectively yet. Herein,
we carefully control the kinetics of reverse cation exchange between
CuxS 2D nanosheets and ligand-coordinated
Cd2+ cations to control the Cu doping sites in CdS nanosheets
(NSs). The substitutional and interstitial Cu dopants were directly
confirmed by spherical aberration-corrected TEM (SACTEM) and their
X-ray absorption spectroscopy (XAS) coordination investigation. Density
functional theory (DFT) calculations and their experimental conductivities
and dopant luminescence performance demonstrated the dramatic differences
that are due to the location of different Cu dopants. These findings
provide deeper insights on dopants’ location regulation in
a nanostructured host semiconductor.