A Programmable Nonvolatile Schottky Diode Based on van der Waals Ferroelectric Junction

Programmable and nonvolatile Schottky junctions are highly desirable for next-generation electronic and neuromorphic systems. However, conventional metal-semiconductor and even van der Waals (vdW) Schottky diodes often suffer from fixed rectifying behaviors or limited tunability. Here, we report a programmable nonvolatile ferroelectric Schottky diode based on a vdW heterojunction between semimetallic 1T'-MoTe₂ and ferroelectric α-In₂Se₃. The diode exhibits near-ideal performance, including a rectification ratio exceeding 10⁴, a leakage current down to 1 pA, and an ideality factor as low as 1.38. By switching ferroelectric polarization, the Schottky barrier can be modulated in a programmable manner, enabling reversible, nonvolatile, and multilevel rectification states. The device demonstrates polarization-dependent photoresponse and transient integrate-and-leak dynamics, closely resembling biological spiking neurons. A spiking neural network is implemented based on this behavior, achieving image recognition accuracy up to 98.4%. This work establishes programmable ferroelectric Schottky diodes as promising candidates for low-power memory, reconfigurable logic, and neuromorphic vision.