Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Surface coordination chemistry of germanium nanocrystals synthesized by microwave-assisted reduction in oleylamine

Journal Article · · Nanoscale
DOI:https://doi.org/10.1039/c9nr09233a· OSTI ID:1728701
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

References (37)

Quantifying the Thermodynamics of Ligand Binding to CsPbBr 3 Quantum Dots journal August 2018
Anhydrous Solution Synthesis of Germanium Nanocrystals from the Germanium(II) Precursor Ge[N(SiMe3)2]2. journal June 2005
Water-Soluble Germanium(0) Nanocrystals: Cell Recognition and Near-Infrared Photothermal Conversion Properties journal April 2007
Facile Synthesis of pH-sensitive Germanium Nanocrystals with High Quantum Yield for Intracellular Acidic Compartment Imaging journal January 2015
Low-temperature (210°C) deposition of crystalline germanium via in situ disproportionation of GeI2 journal November 2012
Density functional study of ethylamine and allylamine on Si(100)-2×1 and Ge(100)-2×1 surfaces journal April 2009
Quantifying Ligand Exchange Reactions at CdSe Nanocrystal Surfaces journal June 2016
Bismuth Doping of Germanium Nanocrystals through Colloidal Chemistry journal July 2017
Purification of Oleylamine for Materials Synthesis and Spectroscopic Diagnostics for trans Isomers journal February 2019
Halogen-Induced Crystallinity and Size Tuning of Microwave Synthesized Germanium Nanocrystals journal August 2019
Solvent Effects on Growth, Crystallinity, and Surface Bonding of Ge Nanoparticles journal April 2018
Sulfur-Capped Germanium Nanocrystals: Facile Inorganic Ligand Exchange journal October 2017
Morphology of Passivating Organic Ligands around a Nanocrystal journal October 2018
All-Inorganic Germanium Nanocrystal Films by Cationic Ligand Exchange journal January 2016
Tuning Confinement in Colloidal Silicon Nanocrystals with Saturated Surface Ligands journal April 2018
Periodic Trends in Organic Functionalization of Group IV Semiconductor Surfaces journal February 2010
Colloidal Synthesis of Air-Stable Crystalline Germanium Nanoparticles with Tunable Sizes and Shapes journal November 2010
Facile Synthesis of Germanium Nanoparticles with Size Control: Microwave versus Conventional Heating journal November 2012
A Solution NMR Toolbox for Characterizing the Surface Chemistry of Colloidal Nanocrystals journal February 2013
Oleylamine in Nanoparticle Synthesis journal February 2013
Thiol-Capped Germanium Nanocrystals: Preparation and Evidence for Quantum Size Effects journal March 2014
Controlling the Trap State Landscape of Colloidal CdSe Nanocrystals with Cadmium Halide Ligands journal January 2015
A General Synthesis Strategy for Monodisperse Metallic and Metalloid Nanoparticles (In, Ga, Bi, Sb, Zn, Cu, Sn, and Their Alloys) via in Situ Formed Metal Long-Chain Amides journal January 2015
NMR Techniques for Noble Metal Nanoparticles journal March 2015
Utilizing Self-Exchange To Address the Binding of Carboxylic Acid Ligands to CdSe Quantum Dots journal July 2010
Monodisperse and Inorganically Capped Sn and Sn/SnO 2 Nanocrystals for High-Performance Li-Ion Battery Anodes journal March 2013
Probing Electronics as a Function of Size and Surface of Colloidal Germanium Nanocrystals journal February 2015
Surface Chemistry Exchange of Alloyed Germanium Nanocrystals: A Pathway Toward Conductive Group IV Nanocrystal Films journal January 2013
The Effects of Chemisorption on the Luminescence of CdSe Quantum Dots journal March 2006
Carrier Multiplication in Semiconductor Nanocrystals: Theoretical Screening of Candidate Materials Based on Band-Structure Effects journal October 2008
Size and Bandgap Control in the Solution-Phase Synthesis of Near-Infrared-Emitting Germanium Nanocrystals journal November 2010
Chalcogenol Ligand Toolbox for CdSe Nanocrystals and Their Influence on Exciton Relaxation Pathways journal February 2014
Ultra-small Ge 1−x Sn x quantum dots with visible photoluminescence journal January 2016
Preparation of alkyl-surface functionalized germanium quantum dots via thermally initiated hydrogermylationElectronic supplementary information (ESI) available: FT-IR spectra of the hydride terminated reaction intermediate and n-undecyl surface Ge nanoclusters. See http://www.rsc.org/suppdata/cc/b3/b314887d/ journal January 2004
Anhydrous solution synthesis of germanium nanocrystals from the germanium(ii) precursor Ge[N(SiMe3)2]2 journal January 2005
Effects of interfacial ligand type on hybrid P3HT:CdSe quantum dot solar cell device parameters journal August 2019
Plasma synthesis of group IV quantum dots for luminescence and photovoltaic applications journal January 2008

Similar Records

Probing the Ligand Exchange of N-Heterocyclic Carbene-Capped Ag2S Nanocrystals with Amines and Carboxylic Acids
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