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

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 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.