Probing electronics as a function of size and surface of colloidal germanium nanocrystals

Alexandra L. Holmes, Jeanette Hütges, Anna Reckmann, Elayaraja Muthuswamy, Klaus Meerholz, Susan M. Kauzlarich

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

Inorganic semiconductor nanoparticles are of significant interest for applications that benefit from their size-dependent properties. The work presented here focuses on the characterization of solution-based microwave synthesized Ge nanocrystals (NCs). Three differently capped Ge NCs were investigated: oleylamine (OAM), dodecanethiol (DDT), and a functionalized N4,N4,N4′,N4′-tetraphenylbiphenyl-4,4′-diamine (TPD) ligand, which is commonly used as hole-transporting units. The optical gaps followed the expected trend for quantum confinement; however, the absolute value depended upon the ligand. We found that the DDT-capped Ge NCs feature consistently larger bandgaps than OAM-capped Ge NCs of a similar size. Cyclic voltammetry (CV) was used to determine the valence band energy for OAM-capped Ge NCs, and the conduction band energy was estimated from the optical gap. By contrast, DDT-capped Ge NCs and the OAM/DDT-capped Ge NCs did not exhibit an oxidative signal in the cyclic voltammetry. This was attributed to the removal of surface defects of OAM-capped Ge NCs through stronger Ge-S surface bonds. TPD-capped Ge NCs were investigated and showed a shift to slightly higher oxidation potential compared with the free ligand and bandgap values in between that of the OAM-capped and DDT-capped Ge NCs. The higher oxidation potential is attributed to TPD orientation, and the bandgap value reflects the lower number of Ge-S bonds on the surface due to ligand sterics.

Original languageEnglish (US)
Pages (from-to)5671-5678
Number of pages8
JournalJournal of Physical Chemistry C
Volume119
Issue number10
DOIs
StatePublished - Mar 12 2015

Fingerprint

Germanium
Nanocrystals
germanium
nanocrystals
Electronic equipment
electronics
Diamines
diamines
Ligands
ligands
Energy gap
Cyclic voltammetry
Oxidation
oxidation
Quantum confinement
Surface defects
surface defects
Valence bands
Conduction bands
energy bands

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Electronic, Optical and Magnetic Materials
  • Surfaces, Coatings and Films
  • Energy(all)

Cite this

Holmes, A. L., Hütges, J., Reckmann, A., Muthuswamy, E., Meerholz, K., & Kauzlarich, S. M. (2015). Probing electronics as a function of size and surface of colloidal germanium nanocrystals. Journal of Physical Chemistry C, 119(10), 5671-5678. https://doi.org/10.1021/jp511929v

Probing electronics as a function of size and surface of colloidal germanium nanocrystals. / Holmes, Alexandra L.; Hütges, Jeanette; Reckmann, Anna; Muthuswamy, Elayaraja; Meerholz, Klaus; Kauzlarich, Susan M.

In: Journal of Physical Chemistry C, Vol. 119, No. 10, 12.03.2015, p. 5671-5678.

Research output: Contribution to journalArticle

Holmes, AL, Hütges, J, Reckmann, A, Muthuswamy, E, Meerholz, K & Kauzlarich, SM 2015, 'Probing electronics as a function of size and surface of colloidal germanium nanocrystals', Journal of Physical Chemistry C, vol. 119, no. 10, pp. 5671-5678. https://doi.org/10.1021/jp511929v
Holmes AL, Hütges J, Reckmann A, Muthuswamy E, Meerholz K, Kauzlarich SM. Probing electronics as a function of size and surface of colloidal germanium nanocrystals. Journal of Physical Chemistry C. 2015 Mar 12;119(10):5671-5678. https://doi.org/10.1021/jp511929v
Holmes, Alexandra L. ; Hütges, Jeanette ; Reckmann, Anna ; Muthuswamy, Elayaraja ; Meerholz, Klaus ; Kauzlarich, Susan M. / Probing electronics as a function of size and surface of colloidal germanium nanocrystals. In: Journal of Physical Chemistry C. 2015 ; Vol. 119, No. 10. pp. 5671-5678.
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