• English
  • Deutsch
  • Log In
    Password Login
    Research Outputs
    Fundings & Projects
    Researchers
    Institutes
    Statistics
Repository logo
Fraunhofer-Gesellschaft
  1. Home
  2. Fraunhofer-Gesellschaft
  3. Artikel
  4. Origin of subgap states in amorphous In-Ga-Zn-O
 
  • Details
  • Full
Options
2013
Journal Article
Title

Origin of subgap states in amorphous In-Ga-Zn-O

Abstract
We present a density functional theory analysis of stoichiometric and nonstoichiometric, crystalline and amorphous In-Ga-Zn-O (c-IGZO, a-IGZO), which connects the recently experimentally discovered electronic subgap states to structural features of a-IGZO. In particular, we show that undercoordinated oxygen atoms create electronic defect levels in the lower half of the band gap up to about 1.5 eV above the valence band edge. As a second class of fundamental defects that appear in a-IGZO, we identify mainly pairs of metal atoms which are not separated by oxygen atoms in between. These defects cause electronic defect levels in the upper part of the band gap. Furthermore, we show that hydrogen doping can suppress the deep levels due to undercoordinated oxygen atoms while those of metal defects just undergo a shift within the band gap. Altogether our results provide an explanation for the experimentally observed effect that hydrogen doping increases the transparency and improves the conductivity of a-IGZO.
Author(s)
Körner, W.
Urban, D.F.
Elsässer, C.
Journal
Journal of applied physics  
Project(s)
ORAMA  
Funder
European Commission EC  
File(s)
Download (359.15 KB)
DOI
10.24406/publica-r-234453
10.1063/1.4826895
Language
English
Fraunhofer-Institut für Werkstoffmechanik IWM  
Keyword(s)
  • In-Ga-Zn-O (IGZO)

  • amorph

  • transparent conductor oxide (TCO)

  • amorphous semiconductor oxide (ASO)

  • hydrogen doping

  • transparency

  • Cookie settings
  • Imprint
  • Privacy policy
  • Api
  • Contact
© 2024