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

Journal Article · · Chemistry of Materials

Ge1–xSnx alloy nanocrystals and Ge1–xSnx/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 Ge1–xSnx 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 Ge1–xSnx 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 Ge1–xSnx/CdS materials. With enhanced photoluminescence in the near-infrared region, Ge1–xSnx core/shell nanocrystals might be useful alternatives to other materials for energy capture and conversion applications and as imaging probes.

Research Organization:
Ames Lab., Ames, IA (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
Grant/Contract Number:
AC02-07CH11358
OSTI ID:
1371893
Report Number(s):
IS-J-9269
Journal Information:
Chemistry of Materials, Vol. 29, Issue 14; ISSN 0897-4756
Publisher:
American Chemical Society (ACS)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 15 works
Citation information provided by
Web of Science

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Cited By (1)

Cubic SnGe nanoalloys: beyond thermodynamic composition limit journal January 2019