Laser-amplified nonvolatile charge trapping effect in semiconductor quantum dot structures

Abstract

Optoelectronic memory is attracting tremendous attention as an emerging strategy to emulate the human visual system. However, most devices to date focus on converting visual information in real time, rarely meeting the expectation of memorizing that information. Here, we report the discovery of a light-induced nonvolatile trapping effect that shows remarkable long-term storage of optical signals in a molybdenum disulfide quantum dot memory structure. Moreover, the charge trapping capability can be enhanced almost threefold after laser irradiation, in contrast to pure electrical means. We ascribe this to barrier modulation driven by the electric and light fields. By designing an optoelectronic memory array, we demonstrate that this effect can be applied simultaneously for image sensing and preprocessing, as well as in neuromorphic reinforcement learning. This work could enable the development of photosensitive artificial intelligence devices.