Highly Responsive Dual-Function Deep-Ultraviolet Neuromorphic Phototransistors Based on Silicon Carbide...

Area of Science:

• Optoelectronics
• Materials Science
• Nanotechnology

Background:

• Two-dimensional (2D) semiconductors offer unique properties for phototransistors and neuromorphic devices.
• Limitations exist in the spectral range and light absorption efficiency of current 2D-semiconductor phototransistors.

Purpose of the Study:

• To develop a high-performance deep-ultraviolet (DUV) sensitive phototransistor.
• To enhance responsivity and detectivity for DUV spectral range applications.
• To explore neuromorphic capabilities by mimicking biological synaptic functions.

Main Methods:

• Integration of molybdenum disulfide (MoS2) with silicon carbide nanoparticles (SiC NPs) to form a van der Waals heterostructure (vdWH).
• Fabrication and characterization of SiC NPs/few-layer MoS2 vdWH phototransistors.
• Evaluation of optoelectronic properties, including responsivity and detectivity at 254 nm.
• Assessment of synaptic functions and simulation of deep neural network (DNN) performance.

Main Results:

• The SiC NPs/few-layer MoS2 vdWH phototransistor demonstrated a 20-fold increase in responsivity (to 1.9 × 10^4 A/W) and an 11-fold increase in detectivity (to 8.4 × 10^13 cm × Hz^1/2/W) at 254 nm.
• The vdWH device successfully mimicked various biological synaptic functions, including facilitation, plasticity, and depression.
• Simulated DNNs using these devices achieved 98.99% image inference accuracy despite photoresponsivity variations.

Conclusions:

• The developed SiC NPs/MoS2 vdWH phototransistor offers ultrahigh performance for DUV photodetection.
• These devices show significant potential for neuromorphic DUV visual sensing and in-sensor computing.
• The dual-function optoelectronic devices pave the way for advanced integrated sensing and computing applications.