Low-Voltage Solution-Processed Zinc-Doped CuI Thin Film Transistors with NOR Logic and Artificial Synaptic Function

Area of Science:

• Materials Science
• Electronics Engineering
• Biophysics

Background:

• Thin film transistors (TFTs) are crucial for electronic devices.
• Copper iodide (CuI) is a promising p-type semiconductor material.
• Low-temperature fabrication methods are desirable for cost-effective manufacturing.

Purpose of the Study:

• To fabricate and characterize low-voltage Zn-doped CuI TFTs using a chitosan dielectric at low temperatures.
• To investigate the effect of Zn-doping on CuI TFT performance.
• To explore the potential applications of these TFTs in logic operations and biosensing.

Main Methods:

• Fabrication of Zn-doped CuI thin films and TFTs at low temperatures.
• Characterization using scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy.
• Electrical performance evaluation, including on/off current ratio, subthreshold swing, and field-effect mobility.

Main Results:

• Zn-doped CuI TFTs exhibited superior on/off current ratio compared to undoped CuI TFTs.
• Achieved an on/off current ratio of 1.58 × 10^4, subthreshold swing of 70 mV/decade, and mobility of 0.40 cm^2V^-1s^-1.
• Demonstrated low-voltage operation (< -2 V) due to the electric-double-layer effect of the chitosan dielectric.
• Implemented NOR logic operation and simulated a pain neuron using the TFTs.

Conclusions:

• Zn-doping effectively enhances CuI TFT performance by addressing copper vacancies.
• Chitosan dielectric enables low-voltage operation and contributes to device stability.
• Zn-doped CuI TFTs show promise for applications in low-cost electronics, complementary circuits, and biosensors.