Projects per year
Understanding the locations of dopant atoms in ensembles of nanocrystals is crucial to controlling the dopants' function. While electron microscopy and atom probe tomography methods allow investigation of dopant location for small numbers of nanocrystals, assessing large ensembles has remained a challenge. Here, we are using high energy X-ray diffraction (HE-XRD) and structure reconstruction via reverse Monte Carlo simulation to characterize nanocrystal structure and dopant locations in ensembles of highly boron and phosphorus doped silicon nanocrystals (Si NCs). These plasma-synthesized NCs are a particularly intriguing test system for such an investigation, as elemental analysis suggests that Si NCs can be "hyperdoped" beyond the thermodynamic solubility limit in bulk silicon. Yet, free carrier densities derived from local surface plasmon resonances suggest that only a fraction of dopants are active. We demonstrate that the structural characteristics garnered from HE-XRD and structure reconstruction elucidate dopant location and doping efficacy for doped Si NCs from an atomic-scale perspective.
Bibliographical noteFunding Information:
This work was supported primarily by the U.S. National Science Foundation through the University of Minnesota MRSEC under Award Number DMR-1420013. K.I.H. acknowledges support by the National Science Foundation Graduate Research Fellowship Program under Grant No. 00039202. U.R.K. and K.I.H. acknowledge partial support by the Army Research Office MURI Grant W911NF-18-1-0240. Parts of this work were carried out in the Characterization Facility, University of Minnesota, which receives partial support from NSF through the MRSEC program. The use of beamline 11-ID-B of the Advanced Photon Source, a U.S. Department of Energy (DOE), Office of Science User Facility, operated for the DOE Office of Science by Argonne National Laboratory, was facilitated under Contract No. DE-AC02-06CH11357.
Copyright © 2019 American Chemical Society.
- High energy X-ray diffraction
- Reverse Monte Carlo simulation
- Structure reconstruction
How much support was provided by MRSEC?
Reporting period for MRSEC
- Period 6
PubMed: MeSH publication types
- Journal Article