Absolute absorption cross sections of ligand-free colloidal germanium nanocrystals

Zachary C. Holman, Uwe R. Kortshagen

Research output: Contribution to journalArticlepeer-review

21 Scopus citations


Extinction spectra of colloidal germanium nanocrystals suspended in benzonitrile without the use of ligands were measured, and absolute absorption cross sections are reported. Comparison to cross sections calculated using the Mie solution to Maxwell's equations reveals that, as the mean nanocrystal size is reduced from 11 to 4 nm, the absorption features below 3.5 eV blueshift because of quantum confinement effects. The shifts are not, however, sufficiently large for the nanocrystal cores to produce the blue photoluminescence commonly observed from germanium nanocrystals. At energies greater than 3.5 eV the Mie and measured cross sections overlap, indicating a bulk-like band structure.

Original languageEnglish (US)
Article number133108
JournalApplied Physics Letters
Issue number13
StatePublished - Mar 26 2012
Externally publishedYes

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)


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