Optically stimulated synaptic devices based on silicon-tin alloyed thin film

Abstract

The implementation of biological synapses onto a hardware platform is an important step toward neuromorphic electronics. However, to replicate biological functions, electronic synapses still have to be reliant on the electric field, or the output of synaptic devices is photonic rather than an electronic synapse. Therefore, the development of optoelectronic synapses with optically stimulated fidelity and flexibility for information sensing and memory processes is a big step toward next-generation computing systems. Herein, the implementation of optical sensing and synaptic functionalities combined has been demonstrated in an artificial optoelectronic synapse based on a silicon-tin alloyed film. The synaptic device can mimic versatile light-stimulated synaptic neuromorphic functions, including excitatory postsynaptic current (ESPC), paired-pulse facilitation (PPF), short-term plasticity (STP), long-term plasticity (LTP), and learning experience. Furthermore, the mimicry of the human visual system is achieved based on these synaptic neuromorphic functions. In addition, the silicon-tin thin film with increased optical absorption provides photonic memory (PM) function under very low light intensity, showing great potential in light-stimulated neuromorphic applications.