Wafer-scale photolithographic fabrication of organic synaptic transistor arrays

Integrating photolithography with polymer semiconductor (PSC) patterning is challenging due to potential damage caused by additional agents such as photoresists and solvents. Here, a feasible approach utilizing photoresist templates to assist PSC patterning is developed. Orthogonal solvents for PSCs are employed to strip the photoresist templates, preventing damage to the PSC from additional agents and stripping solutions during the photolithography process. Following this photoresist-template-assisted approach, wafer-scale organic transistor arrays could be fabricated. The arrays reached a high density of up to 6,500 devices per cm−2 and a large Ion/Ioff ratio of 107. Furthermore, memory recall behavior is demonstrated. Image preprocessing and neuromorphic computing are simulated according to the performance of the optical synaptic transistor arrays. Flexible synaptic transistor arrays have also been fabricated through this approach and reached 92% and 91.7% recognition accuracy in identifying electrocardiogram signals, demonstrating their potential for biomedical devices.