Schottky barrier modulation of bottom contact SnO2 thin-film transistors via chloride-based combustion synthesis. (10th June 2023)

• Record Type: Journal Article
• Authors: Jang, Bongho; Lee, Junhee; Kang, Hongki; Jang, Jaewon; Kwon, Hyuk-Jun
• Is Part Of: Journal of materials science & technology. Volume 148(2023)
• Page Start: 199
• Page End: 208
• Publication Date: 2023-06-10
• Subjects: SnO2 -- Combustion -- Sol-gel -- Schottky contact -- Thin-film transistors; Metals -- Periodicals; Materials science -- Periodicals; Materials science; Metals; Periodicals; 620.1105
• DOI: 10.1016/j.jmst.2022.11.025
• Languages: English
• ISSNs: 1005-0302

Abstract

Highlights: Crystalline Cl-doped SnO2 films were formed by chloride-based combustion synthesis. SnO2 TFTs obtained by combustion process showed significantly improved performance. The devices also exhibited linear IV properties at low V DS of the output curves. Increased carrier concentration with Cl doping could lead to thin potential barriers. The Schottky barrier was remarkably reduced by the enhanced tunneling carrier. Abstract: The enhanced carrier flow at the interface between Au and SnO2 semiconductors, which initially form Schottky contacts, is realized using chloride-based combustion synthesis. Chloride-based combustion systems can achieve chlorine (Cl) doping effects as well as conversion to crystalline SnO2 films at clearly lower temperatures (∼250 °C) than conventional precursors. Due to the Cl doping effect, the high carrier concentration can induce thin potential barriers at the metal/semiconductor (MS) junctions, resulting in carrier injection by tunneling. As a result, compared to conventional SnO2 thin-film transistors, the devices fabricated by combustion synthesis exhibit significantly improved electrical performance with field-effect mobility of 6.52 cm 2 /Vs (∼13 times), subthreshold swing of 0.74 V/dec, and on/off ratio of ∼10 7 below 300 °C. Furthermore, because of the enhanced tunneling carriers induced by the narrowed barrier width, the Schottky barriers are significantly reduced from 0.83 to 0.29 eV (65% decrease) at 250 °C and from 0.42 to 0.17 eV (60% decrease) at 400 °C. Therefore, chloride-based combustion synthesis can contribute to developing SnO2 -based electronics and flexible devices by achieving both high-quality oxide films and improved current flow at the MS interface with low-temperature annealing. Graphical abstract: Image, graphical abstract