Acetylene ion enhanced bonding of PbS nanoparticles to quaterthiophene in thin films

F. Douglas Pleticha, Donghwa Lee, Susan B. Sinnott, Igor L. Bolotin, Michael W. Majeski, Luke Hanley

Research output: Contribution to journalArticle

3 Scopus citations

Abstract

Lead sulfide (PbS) nanoparticles of ∼3-5 nm average diameter were codeposited into quaterthiophene (4T) organic films, which in some cases, were additionally modified by simultaneous 50 eV acetylene ion bombardment. The film composition and PbS-4T bonding were monitored by X-ray photoelectron spectroscopy (XPS) and laser desorption postionization mass spectrometry (LDPI-MS). S2p core-level XP spectra indicated that ion-modified films displayed enhanced bonding between 4T and PbS nanoparticles. LDPI mass spectra found thiophene fragments bound to PbS in ion-modified films. Computational simulations were used to investigate the mechanisms by which the incident particles chemically modified the thiophene-PbS nanoparticle interactions: molecular dynamics, density functional theory simulations were carried out on ±-terthiophene (3T) analogues of 4T films interacting with (PbS) 16 clusters. The simulations showed that, in the absence of acetylene ion modification, a weak charge transfer from the PbS cluster to the nearest 3T molecule occurred, suggestive of little interaction between intact organic matrix molecules and PbS nanoparticles. However, the simulations predicted the formation of a covalent bond between PbS and the oligothiophene film as a result of acetylene ion modification, in support of the experimental observations. These results help explain the recent observation of enhanced photoconductivity in these films upon ion modification (Majeski, M. W.; J. Vac. Sci. Technol. A 2012, 30, 04D109).

Original languageEnglish (US)
Pages (from-to)21693-21698
Number of pages6
JournalJournal of Physical Chemistry C
Volume116
Issue number41
DOIs
Publication statusPublished - Oct 18 2012

    Fingerprint

All Science Journal Classification (ASJC) codes

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

Cite this