Excitation/Inhibition Balancing in 2D Synaptic Transistors with Minority-Carrier Charge Dynamics

Most of the reported synaptic FETs with majority-carrier charge traps suffered from unbalanced excitatory and inhibitory behaviors. Here, we demonstrate an ambipolar WSe2 synaptic FET with the charge dynamics of both electron and hole charge traps. The device shows balanced excitation and inhibition to a gate stimulation, due to the participation of minority-carrier charge traps. As a result, a nearly zero asymmetry with low nonlinearity of 0.04 is realized in long-term potentiation and depression (LTP/LTD). Good device repeatability is confirmed by device-to-device and cycle-to-cycle tests. A high accuracy of 92.8% is realized in the pattern recognition simulation. The proposed devices possess great potential in high-accuracy neuromorphic computing applications.