Flash In2Se3 for neuromorphic computing

The development of next-generation in-memory and neuromorphic computing can be realized with memory transistors based on two-dimensional (2D) ferroelectric semiconductors. Among these, In2Se3 is the most interesting since it possesses ferroelectricity in 2D quintuple layers. However, synthesis of large amounts of In2Se3 crystals with the desired phase has not been previously achieved. We demonstrate here the gram-scale synthesis of α-In2Se3 crystals using a flash-within-flash Joule heating method. This approach allows the synthesis of single-phase α-In2Se3 crystals regardless of the conductance of precursors in the inner tube and enables the synthesis of gram-scale quantities of α-In2Se3 crystals. We then fabricate and use α-In2Se3 flakes as a 2D ferroelectric semiconductor FET artificial synaptic device platform. By modulating the degree of polarization in α-In2Se3 flakes according to the gate electrical pulses, these devices exhibit distinct essential synaptic behaviors. Their synaptic performances show excellent and robust reliability under repeated electrical pulses. Finally, we demonstrate that the synaptic devices achieve an estimated learning accuracy of up to ~87% for Modified National Institute of Standards and Technology patterns in a single-layer neural network system.