Fig. 1. Structure, working mechanism, photoelectrical properties, and behaviors of the B-B SJ-based synapse. (a) Schematic of the device structure and physical mechanism. (b) The device’s photoelectrical properties. The left is optical resistance switching in I–V scanning, and the right is the changing of Schottky barrier in dark and under illumination. (c) The programmable weight states triggered by relearning.

Fig. 2. Receptors, gated channels, and key chemical active molecules synergistically control the generation and transfer of pain signals in a biological nociceptor (left). The operating mechanism of our analog nociceptor based on the B-B SJ structure (right).

Fig. 3. Film characteristics and device properties. (a) The optical microscope (left panel) and AFM (right panel) images. (b) The cross-polarized optical images at different sample angles. The viewing area shows the uniformly changing brightness. (c) The I–V curve of the analog device and the noise curve of the working device.

Fig. 4. Related analog behaviors in our device. (a) The intensity-triggered EPSC jump, enabling the device to exhibit two operation stages of low- and high-threshold stages. (b) The single-pulse EPSC and double-pulse facilitation. The PPF ratio is defined as A2/A1. (c) The dynamic PPF depended on intervals. The PPF ratio is fitted by a double-exponential form. (d) The EPSC programmed by different pulse numbers. The post-stimulation current decay is prolonged with the increasing pulse number. (e) The rehearsal-triggered EPSC jump. The weight changing is defined as ΔWn1=An/A1. (b), (c), and (d) are low-threshold synaptic functions.

Fig. 5. Related behaviors in the individual capacitor. (a) The schematic energy band diagram of electron tunneling at stacked C8-BTBT/Si3N4/SiO2. (b) The schematic of the tunneling mechanism and the conduction current density under the field scanning. (c) The breakdown curve of the capacitor. (d) The tunable pain gain in differing Si3N4 thickness.