Carbon Dots Enable Low-Voltage Memristor Based on CsPbBr3 for Artificial Synapses

Optoelectronic memristors show significant potential for neuromorphic computing but are often limited by high operating voltages. Here, we constructed a low-voltage Ag/CsPbBr3/CDs/FTO photonic memristor by incorporating carbon dots (CDs) as a regulatory medium within the CsPbBr3 perovskite layer. The CDs significantly enhanced memristive performance: their surface defect states and localized electric field regulation enabled stable conductive filament formation and rupture at low voltages. This yielded favorable operational characteristics, including low set/reset voltages (0.72 V/−0.60 V) and preliminary cycling endurance with state retention. Leveraging the device’s continuously tunable conductance, we successfully emulated key synaptic learning behaviors such as paired-pulse facilitation (PPF) and long-term potentiation/depression (LTP/LTD). Implementing its weight-updating characteristics in an artificial neural network (ANN) achieved 92.17% accuracy in handwritten digit classification. This work demonstrates the effective role of CDs in enabling low-voltage, high-performance perovskite photonic memristors, providing a viable strategy for developing low-power neuromorphic hardware.