Surface coordination chemistry of germanium nanocrystals synthesized by microwave-assisted reduction in oleylamine
- Univ. of Southern California, Los Angeles, CA (United States); University of Southern California
- Univ. of California, Davis, CA (United States)
- Univ. of Southern California, Los Angeles, CA (United States)
As surface ligands play a critical role in the colloidal stability and optoelectronic properties of semiconductor nanocrystals, we used solution NMR experiments to investigate the surface coordination chemistry of Ge nanocrystals synthesized by a microwave-assisted reduction of GeI2 in oleylamine. The as-synthesized Ge nanocrystals are coordinated to a fraction of strongly bound oleylamide ligands (with covalent X-type Ge–NHR bonds) and a fraction of more weakly bound (or physisorbed) oleylamine, which readily exchanges with free oleylamine in solution. The fraction of strongly bound oleylamide ligands increases with increasing synthesis temperature, which also correlates with better colloidal stability. Thiol and carboxylic acid ligands bind to the Ge nanocrystal surface only upon heating, suggesting a high kinetic barrier to surface binding. These incoming ligands do not displace native oleylamide ligands but instead appear to coordinate to open surface sites, confirming that the as-prepared nanocrystals are not fully passivated. Furthermore, these findings will allow for a better understanding of the surface chemistry of main group nanocrystals and the conditions necessary for ligand exchange to ultimately maximize their functionality.
- Research Organization:
- Univ. of Southern California, Los Angeles, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- SC0006812
- OSTI ID:
- 1728701
- Alternate ID(s):
- OSTI ID: 1592505
- Journal Information:
- Nanoscale, Journal Name: Nanoscale Journal Issue: 4 Vol. 12; ISSN 2040-3364
- Publisher:
- Royal Society of ChemistryCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
Probing the Ligand Exchange of N-Heterocyclic Carbene-Capped Ag2S Nanocrystals with Amines and Carboxylic Acids
All-inorganic Germanium nanocrystal films by cationic ligand exchange
Journal Article
·
Sat Aug 14 20:00:00 EDT 2021
· Inorganic Chemistry
·
OSTI ID:1866260
All-inorganic Germanium nanocrystal films by cationic ligand exchange
Journal Article
·
Wed Jan 20 19:00:00 EST 2016
· Nano Letters
·
OSTI ID:1242684