# Dual-mode 0D/2D spatial asymmetry optoelectronic device enabled by in situ microzone femtosecond laser deposition

## TL;DR

A new laser technique creates a dual-function optoelectronic device that can act as both a high-speed light sensor and a neuromorphic vision sensor, enabling efficient AI and robotics applications.

## Contribution

A universal M-FLD technique is introduced for in situ fabrication of 0D/2D heterostructures enabling dual-mode optoelectronic devices.

## Key findings

- The device can switch between photodetector and neuromorphic vision sensor modes by changing Vds direction.
- The device achieves high-frequency optical sensing up to 3030 Hz and low energy consumption of 191.2 pJ per activity.
- MNIST digit recognition simulations using the device reach 96.20% accuracy.

## Abstract

To develop artificial intelligence and humanoid robotics, it is crucial to fabricate advanced vision systems with high efficiency and versatility. A key challenge is the functional integration of high-speed photodetectors (PD) and neuromorphic vision sensors (NVS) into a single device, as current studies suffer from complex architectures or fabrication processes. Hence, we propose a universal Microzone Femtosecond Laser Deposition (M-FLD) technique that enables the localized, in situ deposition of zero-dimensional (0D) black phosphorus (BP) nanoparticles onto a two-dimensional (2D) MoS2 channel by ablating a micro-scale solid-state target. By M-FLD and h-BN nanomask, we fabricated a spatial asymmetric 0D/2D heterostructure for highly integrated dual-mode optoelectronic device. By changing the direction of Vds, the device can be converted from PD to NVS. Under the PD mode, the device can sense high-frequency optical signals up to 3030 Hz. Under the NVS mode, the device’s optical energy consumption per activity is only 191.2 pJ. Based on the sensing and memory capabilities, the device is simulated for MNIST handwritten digit recognition, achieving an accuracy of up to 96.20%. This work provides a flexible and powerful platform for fabricating complex heterostructures, paving the way for highly integrated and reconfigurable neuromorphic vision systems.

We introduce a novel in situ microzone Femtosecond laser deposition process for construction of dual-mode 0D/2D spatial asymmetry optoelectronic device, which features for convenient and high precision.