Tunable synaptic behaviors of solution-processed InGaO films for artificial visual systems

Area of Science:

• Materials Science
• Nanotechnology
• Optoelectronics

Background:

• Amorphous metal oxide thin films exhibit persistent photoconductivity, making them suitable for artificial visual systems.
• Developing cost-effective and scalable methods for fabricating these films is crucial for practical applications.

Purpose of the Study:

• To prepare large-scale, uniform amorphous Indium Gallium Oxide (InGaO) thin films using a solution process.
• To investigate the effect of Indium/Gallium (In/Ga) ratio and film thickness on the material's properties and performance in artificial vision.
• To evaluate the image recognition capabilities of InGaO-based artificial vision networks.

Main Methods:

• Fabrication of amorphous InGaO thin films via a low-cost, environmentally friendly solution process.
• Adjustment of In/Ga ratio and film thickness to optimize material properties.
• Characterization of oxygen vacancies and their correlation with photoconductivity.
• Construction and testing of a three-layer artificial vision network using InGaO thin-film transistors.

Main Results:

• Achieved large-scale, uniform InGaO films with adjustable In/Ga ratio and thickness.
• Increased In/Ga ratio and film thickness led to more oxygen vacancies and enhanced post-synaptic current.
• Demonstrated improved transition from short-term to long-term plasticity with optimal film parameters.
• Observed a high conductance response difference (2.88 μA) and improved decay ratio (53.24%) for non-volatile artificial visual memory.
• Attained up to 91.32% accuracy in image recognition using a three-layer artificial vision network.

Conclusions:

• Low-cost, easy-to-handle amorphous InGaO thin films are promising for artificial visual systems.
• The In/Ga ratio and film thickness are critical parameters for tuning performance.
• These materials enable high image clarity, non-volatile memory, and efficient visual information processing.