Printable Coffee‐Ring Structures for Highly Uniform All‐Oxide Optoelectronic Synaptic Transistors

Printable oxide transistors have emerged as important optoelectronic synaptic devices to emulate the human visual cognitive system by integrating both photo-sensing and visual perception functions. However, the inferior electrical performance and low pixel density of printed oxide synaptic transistors impede their implementation of complex neuromorphic computing. Herein, a printable all-oxide optoelectronic synaptic transistor array based on a modified coffee-ring structure of indium tin oxide (ITO) is reported. The extraordinary structural design endows the printed ITO transistors with high device uniformity, outstanding electrical performance, and superior process efficiency. Furthermore, a 10 x 12 coffee-ring structure optoelectronic synaptic transistor array with a high spatial resolution (142 dpi) exhibits durable visual detection and memory behaviors. Meanwhile, an artificial neural network based on the coffee-ring structure synaptic transistors exhibits high accuracy in the recognition rate. These results promise the efficiency of the exceptional printing strategy in developing advanced optoelectronic synaptic transistors for artificial visual systems.