Solution-processed ytterbium oxide dielectrics for low-voltage thin-film transistors and inverters

Abstract High permittivity (high k) metal-oxide thin films fabricated via solution processes have recently received much attention for the construction of low-operating voltage and high-performance thin-film transistors (TFTs). In this report, amorphous ytterbium oxide (Yb 2 O 3 ) thin films were fabricated by spin coating and their applications in TFTs were explored. The physical properties of the solution-processed Yb 2 O 3 thin films processed at different annealing temperatures were systematically investigated using various characterization techniques. To explore the feasibility of the Yb 2 O 3 thin films as gate dielectrics for oxide TFTs, In 2 O 3 TFTs based on Yb 2 O 3 dielectrics were integrated. All the devices could be operated at 3 V, which is critical for the applications in portable, battery-driven, and low-power electronic devices. The optimized In 2 O 3 /Yb 2 O 3 TFT exhibits high electrical performances, including field-effect mobility of 4.98 cm 2 /V s, on/off current ratio of ~ 10 6 , turn-on voltage around 0 V, and subthreshold swing of 70 mV/decade, respectively. To demonstrate the potential of In 2 O 3 /Yb 2 O 3 TFT toward more complex logic application, the unipolar inverter was further constructed.