Two-Dimensional LaNb2O7 Nanosheets for UV Wavelength-Selective Neuromorphic Vision and Temporal Computing

In recent years, neuromorphic synaptic devices have emerged as an important hardware for building neuromorphic vision systems, due to their ability to simultaneously encode, store and process information during perception. However, most neuromorphic vision research has focused on the visible light band, and the utilization of ultraviolet (UV) spectral information remains limited. Meanwhile, device systems that integrate wavelength discrimination with brain-like temporal processing are still lacking. Here, we report a UV photo-synaptic device based on two-dimensional (2D) LaNb2O7 (LNO) nanosheets. Benefiting from the wide bandgap property of LNO and the defect-induced persistent photoconductivity, this device exhibits a significant wavelength-dependent response in the UVA, UVB and UVC regions, together with synaptic plasticity and temporal memory characteristics. Using a 5 × 6 device array, image perception and dynamic memory under different UV regions were achieved. In addition, based on the device response characteristics, proof-of-concept demonstrations for static image classification and continuous action recognition tasks were carried out, highlighting its potential for neuromorphic vision applications. This work offers a insights for the application of wide bandgap 2D oxides in UV neuromorphic devices, and provides a material basis as well as device guidance for the development of low-power intelligent vision systems.