Insight about electrical properties of low-temperature solution-processed Al-doped ZnO nanoparticle based layers for TFT applications

• Published in: Materials science & engineering. B, Solid-state materials for advanced technology Solid-state materials for advanced technology, 2016-12, Vol.214, p.11-18
• Main Authors: Diallo, Abdou Karim, Gaceur, Meriem, Fall, Sadiara, Didane, Yahia, Ben Dkhil, Sadok, Margeat, Olivier, Ackermann, Jörg, Videlot-Ackermann, Christine
• Format: Article
• Language: English
• Subjects: Al-doped nanoparticles AZO; Aluminum; Carrier density; Charge density; Condensed Matter; Conductivity; Current carriers; Doping; Electrical properties; Electrical resistivity; Electron mobility; Electron spin; Heat treatment; Low temperature; Materials Science; Microstructure; Morphology; Nanoparticles; Nanostructure; Physics; Semiconductor devices; Semiconductor materials; Temperature; Thin film; Thin film transistors; Thin films; Zinc oxide; Zinc oxides
• ISSN: 0921-5107; 1873-4944
• DOI: 10.1016/j.mseb.2016.07.015

[Display omitted] •Al-doped ZnO (AZO) nanoparticles.•Impact of dispersion state and solid state on electrical properties.•Extrinsic doping with Al for high conducting AZO nanoparticle based layers.•Low-temperature operating nanoparticulate AZO TFTs. Aluminium-doped zinc oxide nanoparticles (NPs) with controlled Al doping contents (AZOx with x=0–0.8at% of Al) were explored as new oxide semiconductor materials to study the impact of doping on both solution and solid states. Polycrystalline AZOx thin films were produced by spin-coating the dispersions following by a thermal post-treatment at low-temperature (80°C or 150°C). The coated AZOx films were employed as active layer in thin-film transistors. Morphology and microstructure were studied by scanning electron microscopy and X-ray diffraction. The impact on the device performances (mobility, conductivity, charge carrier density) of Al-doping content together with the solution state was examined. Spin-coated films delivered an electron mobility up to 3×10−2cm2/Vs for the highest Al-doping ratio AZO0.8. Despite highly different morphologies, extrinsic doping with aluminium significantly increases the conductivity of low temperature solution-processed AZOx NPs series based layers by several orders of magnitude from AZO0 to AZO0.8.