Optoelectronic synapse based on 2D metal-organic framework Cu₃(HHTP)₂ for neuromorphic processing of both visual and auditory information

Two-dimensional conjugated Metal–organic frameworks (2D c-MOFs) hold immense potential in neuromorphic due to their high porosity, excellent specific surface area, highly tunable chemical properties, and excellent electrical conductivity. Herein, a two-terminal optoelectronic synapse based on the Cu₃(HHTP)₂ film is fabricated using a layer-by-layer self-assembly method. The device demonstrates outstanding synaptic functionalities, including pair-pulse facilitation (PPF), spike-width-dependent plasticity (SWDP) and spike-rate-dependent plasticity (SRDP). Furthermore, the broad absorption of Cu₃(HHTP)₂ film in the visible light ranges enables the device a broad spectral response, which is crucial for realizing the color distinction and associative memory. Eventually, simulations based on the neuromorphic speech recognition system reveal the device's ability to achieve the high spoken digit recognition accuracy, maintaining robust performance even under noisy environments. These results highlight the potential of Cu₃(HHTP)₂-based optoelectronic synapses as a promising platform for next-generation neural computing leveraging the unique properties of MOFs.