Mimic Drug Dosage Modulation for Neuroplasticity Based on Charge‐Trap Layered Electronics

The human brain is often likened to an incredibly complex and intricate computer, rather than electrical devices, consisting of billions of neuronal cells connected by synapses. Different brain circuits are responsible for coordinating and performing specific functions. The reward pathway of the synaptic plasticity in the brain is strongly related to the features of both drug addiction and relief. In the current study, a synaptic device based on layered hafnium disulfide (HfS2) is developed for the first time, to emulate the behavioral mechanisms of drug dosage modulation for neuroplasticity. A strong gate‐dependent persistent photocurrent is observed, arising from the modulation of substrate‐trapping events. By controlling the polarity of gate voltage, the basic functions of biological synapses are realized under a range of light spiking conditions. Furthermore, under the control of detrapping/trapping events at the HfS2/SiO2 interface, positive/negative correlations of the An/A1 index, which significantly reflected the weight change of synaptic plasticity, are realized under the same stimulation conditions for the emulation of the drug‐related addition/relief behaviors in the brain. The findings provide a new advance for mimicking human brain plasticity. In this study, controlling the polarity of gate field, positive/negative correlations of the An/A1 index arising from the substrate‐trapping events, reflected the weight change of neuroplasticity, are realized under the same stimulations for the emulation of drug‐dosage‐related addition/relief behaviors in brain (where A1 and An represent the postsynaptic responses triggered by the 1st and nth input spikes, respectively).