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This content will become publicly available on June 27, 2018

Title: Germanium–Tin/Cadmium Sulfide Core/Shell Nanocrystals with Enhanced Near-Infrared Photoluminescence

Ge 1–xSn x alloy nanocrystals and Ge 1–xSn x/CdS core/shell nanocrystals were prepared via solution phase synthesis, and their size, composition, and optical properties were characterized. We found that the diameter of the nanocrystal samples ranged from 6 to 13 nm. Furthermore, the crystal structure of the Ge 1–xSn x materials was consistent with a cubic diamond phase, while the CdS shell was consistent with the zinc blende polytype. Inclusion of Sn alone does not result in enhanced photoluminescence intensity; however, adding an epitaxial CdS shell onto the Ge 1–xSn x nanocrystals does enhance the photoluminescence up to 15-fold versus that of Ge/CdS nanocrystals with a pure Ge core. There is more effective passivation of surface defects, and a consequent decrease in the level of surface oxidation, by the CdS shell as a result of improved epitaxy (smaller lattice mismatch) is the most likely explanation for the increased photoluminescence observed for the Ge 1–xSn x/CdS materials. With enhanced photoluminescence in the near-infrared region, Ge 1–xSn x core/shell nanocrystals might be useful alternatives to other materials for energy capture and conversion applications and as imaging probes.
Authors:
 [1] ;  [1] ;  [1] ;  [1] ; ORCiD logo [1] ; ORCiD logo [1] ; ORCiD logo [1]
  1. Ames Lab. and Iowa State Univ., Ames, IA (United States); Iowa State Univ., Ames, IA (United States). Dept. of Chemistry
Publication Date:
Report Number(s):
IS-J-9269
Journal ID: ISSN 0897-4756
Grant/Contract Number:
AC02-07CH11358
Type:
Accepted Manuscript
Journal Name:
Chemistry of Materials
Additional Journal Information:
Journal Volume: 29; Journal Issue: 14; Journal ID: ISSN 0897-4756
Publisher:
American Chemical Society (ACS)
Research Org:
Ames Laboratory (AMES), Ames, IA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
OSTI Identifier:
1371893