Sensitive MoS2 photodetector cell with high air-stability for multifunctional in-sensor computing

Abstract

With the development of artificial intelligence and the Internet of Things, the number of sensory nodes is growing rapidly, leading to the exchange of large quantities of redundant data between sensors and computing units. In-sensor computing schemes, which integrate sensing and processing, have provided a promising route to addressing the sensing/processing bottleneck by reducing power consumption, time delay and hardware redundancy. In this study, an in-sensor computing architecture involving a photoelectronic cell based on a wafer-scale two-dimensional MoS2 thin film was demonstrated. The MoS2 photodetector cell used a top-gate device structure with indium tin oxide (ITO) as the transparent gate electrode, which exhibited high air-stability and a high photoresponsivity (R) up to 555.8 A W–1 at an illumination power density (Pin) of 16.0 µW cm–2 (λ = 500 nm). Additionally, a MoS2 photodetector array with uniform photoresponsive characteristics was achieved. Furthermore, logic gates, including inverter, NAND, and NOR, were achieved based on MoS2 photodetector cells. Such multifunctional and robust in-sensor computing was ascribed to the uniform wafer-scale MoS2 film grown by atomic layer deposition (ALD) and the unique device structure. Because the detection of optical signals and logic operations were achieved through MoS2 photodetector cells with area efficiency, the proposed in-sensor computing device paves the way for potential applications in high-performance, integrated sensing and processing systems.

Keywords

• In-sensor computing
• Photodetectors
• MoS2
• Atomic layer deposition
• Transparent electrode