Enhanced Photoluminescence in a Neuromorphic 2D Memitter Based on WS2 via Plasmonic Nanoparticle Self-Assembly

All-optical neuromorphic devices based on adaptive two-dimensional (2D) materials have the potential for mimicking the complex processing and memory capabilities of biological synapses. Recent research demonstrated synaptic plasticity and visual memory in WS2 monolayer-based 2D memitters (i.e., an emitter with memory). However, improving their optical performances is crucial for extending their scalability. Since the neuromorphic functionalities of 2D memitters relies on O2 and H2O desorption/absorption on WS2, a careful balance between photoluminescence intensity and surface preservation is critical. Here, we investigate the enhancement of time-dependent photoluminescence response, achieved through coupling WS2 flakes with plasmonic nanoparticles obtained by liquid phase infiltration of gold in self-assembled block copolymer micelles. The localized surface plasmon resonance of gold nanoparticles amplifies the electric field and improves light-matter interactions. This method enhances the 2D memitter optical properties while preserving its adaptive photoluminescence response, thus enabling neuromorphic behavior under optical stimuli.