Ultrasensitive Photonic Synapse with Broadband Response Based on the PdSe₂ QDs/GeSe Thin Film

Photonic synapses that integrate optical sensing with synaptic functionalities are becoming increasingly important in the advancement of neuromorphic computing systems. However, achieving broad-band sensing and preprocessing capabilities under weak light illumination remains a significant challenge. Herein, we report a photonic synapse based on the PdSe2 QDs/GeSe thin film which leverages the high photosensitivity and favorable band alignment of the PdSe2 QDs/GeSe heterojunction to emulate essential synaptic functionalities. It also exhibits a broadband photoresponse ranging from ultraviolet (UV, 365 nm) to near-infrared (NIR, 850 nm) and maintains performance under an ultraweak light detection threshold down to 0.15 μW cm–2. Furthermore, its potential applications for optical information processing and facial recognition are demonstrated. This work provides a promising strategy for developing multifunctional photonic synapses based on the PdSe2 QDs/GeSe thin film.