Indium Tungsten Oxide Thin Films for Flexible High-Performance Transistors and Neuromorphic Electronics

Area of Science:

• Materials Science
• Electronics Engineering
• Nanotechnology

Background:

• High-performance thin-film transistors (TFTs) typically require high processing temperatures, limiting their use in flexible electronics.
• Amorphous oxide semiconductors offer a potential solution for flexible and transparent electronic devices.

Purpose of the Study:

• To develop a novel amorphous oxide semiconductor, indium tungsten oxide (IWO), for high-performance flexible TFTs (FTFTs).
• To investigate the electrical characteristics and stability of IWO-based FTFTs.
• To explore the application of IWO TFTs in neuromorphic computing.

Main Methods:

• Amorphous IWO thin films were deposited using radio frequency sputtering at room temperature.
• Post-annealing was performed at temperatures as low as 270 °C.
• Flexible TFTs were fabricated and characterized for electrical performance and bending stability.
• IWO TFTs were implemented as synaptic devices to demonstrate neuromorphic computing capabilities.

Main Results:

• Low-temperature processed IWO films exhibited smooth morphology, good adhesion, and high carrier density.
• Achieved excellent TFT characteristics: mobility of ~25.86 cm²/V s, subthreshold swing of ~0.30 V/decade, threshold voltage of ~-1.5 V, and on/off ratio of ~5.6 × 10⁵.
• Demonstrated stable operation during device bending.
• IWO TFTs functioned as synapses with up to 138% paired-pulse facilitation and were used to create a high-pass dynamic temporal filter.

Conclusions:

• Indium tungsten oxide is a promising material for low-voltage, high-performance flexible electronics.
• The developed IWO FTFTs offer a viable platform for flexible displays, sensors, and neuromorphic computing applications.
• Low-temperature processing of IWO enables fabrication on flexible substrates, expanding the scope of electronic device applications.