Structural, chemical, optical, and electrical evolution of solution-processed SnO2 films and their applications in thin-film transistors

Abstract

We demonstrate the formation of n-type transparent SnO2 thin films by solution process. The influences of annealing temperature (200 °C–700 °C) on the microstructural, chemical, optical, and electrical performances of the SnO2 thin films are systematically investigated by a variety of characterization techniques. The results reveal that the solution-processed SnO2 thin film undergoes the elimination of organic and Cl-related residues along with the conversion of Sn(OH)4 to form crystalline SnO2, with the rising annealing temperature. This also leads to the improvement of the Hall mobility (from 0.3 to 13.7 cm2 V−1 s−1). Furthermore, the optimized SnO2 thin-film transistor annealed at 450 °C exhibits the highest saturation mobility of 0.511 cm2 V−1 s−1, on/off current ratio of 2.3 × 104, on voltage of −23.6 V, and subthreshold swing of 5.06.