Reconfigurable logic and neuromorphic circuits based on electrically tunable two-dimensional homojunctions

A homojunction device made from two-dimensional tungsten diselenide can be used to create circuits that exhibit multifunctional logic and neuromorphic capabilities with simpler designs than conventional silicon-based systems. Reconfigurable logic and neuromorphic devices are crucial for the development of high-performance computing. However, creating reconfigurable devices based on conventional complementary metal-oxide-semiconductor technology is challenging due to the limited field-effect characteristics of the fundamental silicon devices. Here we show that a homojunction device made from two-dimensional tungsten diselenide can exhibit diverse field-effect characteristics controlled by polarity combinations of the gate and drain voltage inputs. These electrically tunable devices can achieve reconfigurable multifunctional logic and neuromorphic capabilities. With the same logic circuit, we demonstrate a 2:1 multiplexer, D-latch and 1-bit full adder and subtractor. These functions exhibit a full-swing output voltage and the same supply and signal voltage, which suggests that the devices could be cascaded to create complex circuits. We also show that synaptic circuits based on only three homojunction devices can achieve reconfigurable spiking-timing-dependent plasticity and pulse-tunable synaptic potentiation or depression characteristics; the same function using complementary metal-oxide-semiconductor devices would require more than ten transistors.