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Title: Visible-light-induced instability in amorphous metal-oxide based TFTs for transparent electronics

We investigate the origin of visible-light-induced instability in amorphous metal-oxide based thin film transistors (oxide-TFTs) for transparent electronics by exploring the shift in threshold voltage (V{sub th}). A large hysteresis window in amorphous indium-gallium-zinc-oxide (a-IGZO) TFTs possessing large optical band-gap (≈3 eV) was observed in a visible-light illuminated condition whereas no hysteresis window was shown in a dark measuring condition. We also report the instability caused by photo irradiation and prolonged gate bias stress in oxide-TFTs. Larger V{sub th} shift was observed after photo-induced stress combined with a negative gate bias than the sum of that after only illumination stress and only negative gate bias stress. Such results can be explained by trapped charges at the interface of semiconductor/dielectric and/or in the gate dielectric which play a role in a screen effect on the electric field applied by gate voltage, for which we propose that the localized-states-assisted transitions by visible-light absorption can be responsible.
Authors:
 [1]
  1. Department of Electronic Materials Engineering, Kwangwoon University, Seoul 139-701 (Korea, Republic of)
Publication Date:
OSTI Identifier:
22299628
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Advances; Journal Volume: 4; Journal Issue: 10; Other Information: (c) 2014 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ABSORPTION; DIELECTRIC MATERIALS; ELECTRIC FIELDS; ELECTRIC POTENTIAL; GALLIUM; HYSTERESIS; INDIUM; INSTABILITY; IRRADIATION; SEMICONDUCTOR MATERIALS; STRESSES; THIN FILMS; ZINC OXIDES