Highly Textured Assembly of Engineered Si Nanowires for Artificial Synapses Model

Uniformly aligned silicon nanowire (SiNW) arrays are promising building blocks for a range of photoelectrical and sensing devices attributable to their unique optical, electrical, structural, mechanical, and thermal properties. In particular, the large-area and high-density assembled planar SiNWs arrays with a horizontal orientation can have critical applications in nanoelectronics. However, the fabrication of textured silicon nanowires with high throughput also faces the challenges of cost, processing cycle, and precision. Herein we demonstrate a high throughput fabrication and horizontal texture alignment stratagem for wafer-scale high-density SiNWs, which thereby is employed in ionic-gel electrolyte gated pseudodiode transistor for artificial synapses. Integration hypergravity (HiGee) into controllable metal-assisted chemical etching process enables the vertically aligned SiNWs thus obtained with unprecedented uniformity, high aspect ratio, and very smooth surface. Highly horizontal textured SiNWs with good semiconductor character were obtained from a bio-inspired in situ assembled method by mechanical shear force induced controlled breakage using graphene quantum dots (GQDs) as a solid lubricant. Finally, the textured SiNW channel-based pseudodiode transistor exhibits excellent activity-dependent inhibitory and excitatory synaptic behaviors with good operational performance mimicked from biological synapse system. The proposed artificial synapse may find potential applications in energetic effective neuromorphic platforms. The fabrication strategy and the highly textured SiNW arrays also hold great promise for other nanostructure building blocks.