Size dependence in hexagonal mesoporous germanium: Pore wall thickness versus energy gap and photoluminescence

Gerasimos S. Armatas, Mercouri G. Kanatzidis

Research output: Contribution to journalArticle

30 Citations (Scopus)

Abstract

A series of hexagonal mesoporous germanium semiconductors with tunable wall thickness is reported. These nanostructures possess uniform pores of 3.1-3.2 nm, wall thicknesses from 1.3 to 2.2 nm, and large internal BET surface area in the range of 404-451 m2/g. The porous Ge framework of these materials is assembled from the templated oxidative self-polymerization of (Ge 9)4- Zintl clusters. Total X-ray scattering analysis supports a model of interconnected deltahedral (Ge9)-cluster forming the framework and X-ray photoelectron spectroscopy indicates nearly zero-valence Ge atoms. We show the controllable tuning of the pore wall thickness and its impact on the energy band gap which increases systematically with diminishing wall thickness. Furthermore, there is room temperature photoluminescence emission which shifts correspondingly from 672 to 640 nm. The emission signal can be quenched via energy transfer with organic molecules such as pyridine diffusing into the pores.

Original languageEnglish
Pages (from-to)3330-3336
Number of pages7
JournalNano letters
Volume10
Issue number9
DOIs
Publication statusPublished - Sep 8 2010

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Keywords

  • Mesoporous
  • nanoporous
  • quantum confinement
  • zintl compounds

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

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