High electron mobility thin-film transistors based on Ga2O3grown by atmospheric ultrasonic spray pyrolysis at low temperatures

Abstract

We report on thin-film transistors based on Ga2O3films grown by ultrasonic spray pyrolysis in ambient atmosphere at 400-450°C. The elemental, electronic, optical, morphological, structural, and electrical properties of the films and devices were investigated using a range of complementary characterisation techniques, whilst the effects of post deposition annealing at higher temperature (700°C) were also investigated. Both as-grown and post-deposition annealed Ga2O3films are found to be slightly oxygen deficient, exceptionally smooth and exhibit a wide energy bandgap of ∼4.9eV. Transistors based on as-deposited Ga2O3films show n-type conductivity with the maximum electron mobility of ∼2cm2/V s.