Low intensity IR detection along with photonic synaptic device fabrication using 2D reduced graphene oxide & graphene quantum dots for enhancing artificial visual system.

Abstract

Information sensing, processing and memory operation are the building blocks Artificial Visual System. Photonic Synapse is a promising component that can enhance the visual processing efficiency owing to the fast responsivity, low power consumption and large bandwidth. Herein, a Photo-synapse has been constructed having heterostructure configuration between Reduced Graphene Oxide (rGO) and Graphene Quantum Dot (GQD) which have been synthesized with a simple Hydrothermal method. By the high interfacial effect of high photosensitive characteristic of GQD and large surface area, enhanced semiconducting bandgap and high charge carrier mobility performance of rGO 2D layer shows fundamental synaptic behaviours like Excitory Post Synaptic Current (EPSC), Pair Pulse Facilitation (PPF), plasticity i.e. transition from short term memory (STM) to long term memory (LTM) etc. Following the completion of all required characterizations of materials, such as XRD, UV-Vis, and PL, we began optimizing our device with the appropriate light intensity. The final optimized version of our device is having an area of channel region 2×4 mm2 with a 2 layers of rGO and 1 layer of GQD. One of the key point of our device, it is showing good response in low intensity Infra-Red radiation which totally neutralize the effect of thermal noise which is an essential issue while working with IR. At last the different synaptic performance like it’s EPSC, PPF, Plasticity etc. of the device has been successfully stimulated. Not only that our device is showing a very good non-volatile memory nature and stability at STM.