Electroluminescent synaptic devices with logic functions

The incorporation of light into synaptic devices for neuromorphic computing with low energy consumption and high intelligence is greatly inspired by the development of optogenetics in neuroscience. However, the use of light as the outputs of synaptic devices has not been demonstrated yet, impeding the full optoelectronic integration of artificial neural systems. Here we demonstrate electroluminescent synaptic devices based on silicon nanocrystals (Si NCs) with optical outputs. These devices exhibit a series of important synaptic functionalities including paired-pulse facilitation (PPF), transition from short-term plasticity (STP) to long-term plasticity (LTP) and spike-timing-dependent plasticity (STDP). In the meantime, logic functions such as AND, OR, NAND and NOR are realized in the intercoupled Si-NC-based electroluminescent synaptic devices. The current results not only help realize the bidirectional conversion between electrical and optical signals in synaptic devices, but also contribute to the development of the in-memory computing capacity of synaptic devices.