Positron annihilation and constant photocurrent method measurements on a-Si:H films: A comparative approach to defect identification

P. M. Gordo, M. F. Ferreira Marques, C. Lopes Gil, A. P. de Lima, G. Lavareda, C. Nunes de Carvalho, A. Amaral, Zs Kajcsos

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Defect structure of hydrogenated amorphous silicon thin-films was studied by positron annihilation spectroscopy (PAS), whereas the density of states below the Fermi level was measured by constant photocurrent method (CPM). Divacancies and large vacancy clusters were identified as the main defects present in these films, with relative concentrations strongly dependent on the rf-power. Correlation between PAS, CPM results and I(V) characteristics of solar cells suggests the creation of energy levels above the Fermi energy, not observable by CPM, related to large vacancy clusters.

Original languageEnglish
Pages (from-to)220-223
Number of pages4
JournalRadiation Physics and Chemistry
Volume76
Issue number2
DOIs
Publication statusPublished - Feb 2007

Keywords

  • Constant photocurrent method
  • Defects
  • Density of states
  • Doppler broadening
  • Variable-energy positron annihilation
  • a-Si:H

ASJC Scopus subject areas

  • Radiation

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