Zn²⁺ Engineered Low-Barrier LiNbO₃ Enables Visible-Light Programmable Ferroelectric Memristors for Noise-Immune...

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Lithium niobate (LiNbO3) possesses excellent ferroelectric and optical properties, making it promising for optoelectronic integrated devices.
• High polarization switching energy barriers in LiNbO3 limit its use with low-power visible light, hindering practical applications.

Purpose of the Study:

• To reduce the polarization switching energy barrier in LiNbO3 for low-power visible light operation.
• To develop high-performance ferroelectric optoelectronic systems with integrated sensing, storage, and computation.

Main Methods:

• Doping LiNbO3 with Zn2+ ions to modulate the lattice structure and suppress NbLi antisite defects.
• Fabrication of a Pt/Zn-LiNbO3/Nb:SrTiO3 optoelectronic bimodal memristor.
• Evaluation of device performance including switching voltage, on/off ratio, resistance states, retention, and endurance.
• Emulation of synaptic functions and construction of an optical reservoir computing neural network.

Main Results:

• Zn2+ doping reduced the polarization switching energy barrier by approximately 69%, enabling polarization reversal under 10 mW cm-2 visible light.
• The memristor demonstrated ultra-stable switching, a high on/off ratio (~10^3), 16 distinguishable resistance states, retention >10^4 s, and endurance up to 10^8 cycles.
• The device successfully emulated synaptic functions and achieved 98.6% recognition accuracy on the MNIST dataset using an optical reservoir computing network.

Conclusions:

• Zn2+-doped LiNbO3 offers a viable pathway for low-barrier, high-performance ferroelectric optoelectronic devices.
• The developed memristor exhibits potential for advanced applications in neuromorphic computing and artificial intelligence, mimicking biological systems.
• This work presents a new materials design strategy for integrated optoelectronic systems.