Samsung Advanced Institute of Technology

Two-dimensional (2D) semiconductors, especially transition metal dichalcogenide (TMD) monolayers, are being extensively studied for electronic and optoelectronic applications. Beyond intensive studies on single transistors and photodetectors, the recent advent of large-area synthesis of these atomically thin layers has paved a way for 2D integrated circuits, such as digital logic circuits and image sensors, achieving an integration level of ~100 devices thus far. Here we report on a decisive advance in 2D integrated circuits, where we increase the device integration scale by tenfold, and propel the functional complexity of 2D electronics to an unprecedented level. Concretely, we have developed an analog optoelectronic processor inspired by biological vision, where 32 ？ 32 = 1,024 MoS2 photo-sensitive field-effect transistors (FETs) manifesting persistent photoconductivity (PPC) effects are arranged in a crossbar array. This optoelectronic processor with PPC memory mimics two core functions of human vision: it captures and stores an optical image into electrical data, like the eye and optic nerve chain, and then recognizes this electrical form of the captured image, like the brain, by executing analog in-memory neural net computing. In our highlight demonstration, the MoS2 FET crossbar array optically images 1,000 handwritten digits and electrically recognizes these imaged data with 94％ accuracy.