Device-Level in-Sensor Olfactory Perception System Based on Array of PCBM-MAPbI₃ Heterostructure Transistors

Although there are significant advancements in device-level artificial tactile and visual perception systems based on in-sensor computing paradigms, the development of hardware-implemented neuromorphic olfactory system is still in its early stages. One of the primary challenges in this field is that most of the gas sensors lack the capability to fuse the sensing and computing functions in a single sensor. Through surface passivation and interface engineering, this work introduces a device-level artificial olfactory system utilizing array of PCBM-MAPbI₃ heterostructure transistors. Noteworthly, the formation of metastable intermediate phase NH₃PbI₃•MA can occur at room temperature and can be used to store gas sensory information. Both gas pulse and electrical pulse can dynamically modulate the amount of this intermediate phase, and then change the channel conductance (weight), realizing the fusion of the sensing and synaptic functions in single device. Based on these excellent properties, the spatiotemporal information of gas diffusion can be encoded and processed simultaneously. As a result, an in-sensor olfactory perception system is successfully demonstrated based on 5 × 5 PCBM-MAPbI₃ heterostructure transistor array, which can be used for detecting the distance and direction of the hazardous gas. This work paves the way for future application of real-time and data-intensive machine-olfactory system.