Schottky barrier modulation of bottom contact SnO2 thin-film transistors via chloride-based combustion synthesis

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 sys-tems can achieve chlorine (Cl) doping effects as well as conversion to crystalline SnO2 films at clearly lower temperatures ( -250 degrees 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 de-vices fabricated by combustion synthesis exhibit significantly improved electrical performance with field-effect mobility of 6.52 cm2/Vs (-13 times), subthreshold swing of 0.74 V/dec, and on/off ratio of-107 below 300 degrees 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 degrees C and from 0.42 to 0.17 eV (60% decrease) at 400 degrees C. Therefore, chloride-based combustion synthesis can con-tribute 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.(c) 2023 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Automated summary

The enhanced carrier flow and improved electrical performance at the Au/SnO2 interface are achieved through chloride-based combustion synthesis. The synthesis method enables Cl doping effects and crystalline SnO2 film formation at lower temperatures compared to conventional precursors. The high carrier concentration induced by Cl doping results in thin potential barriers at the metal/semiconductor junction, enabling carrier injection by tunneling. The devices fabricated by combustion synthesis exhibit significantly improved electrical performance, including higher field-effect mobility, lower subthreshold swing, and higher on/off ratio.