Monolayer optical memory cells based on artificial trap-mediated charge storage and release

• Published in: Nature communications Vol. 8; no. 1; pp. 14734 - 8
• Main Authors: Lee, Juwon, Pak, Sangyeon, Lee, Young-Woo, Cho, Yuljae, Hong, John, Giraud, Paul, Shin, Hyeon Suk, Morris, Stephen M., Sohn, Jung Inn, Cha, SeungNam, Kim, Jong Min
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 24.03.2017; Nature Publishing Group; Nature Portfolio
• Subjects: 140/133; 142/126; 639/301/1005/1007; 639/301/357/1018; Graphene; Humanities and Social Sciences; Interfaces; multidisciplinary; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms14734

Monolayer transition metal dichalcogenides are considered to be promising candidates for flexible and transparent optoelectronics applications due to their direct bandgap and strong light-matter interactions. Although several monolayer-based photodetectors have been demonstrated, single-layered optical memory devices suitable for high-quality image sensing have received little attention. Here we report a concept for monolayer MoS 2 optoelectronic memory devices using artificially-structured charge trap layers through the functionalization of the monolayer/dielectric interfaces, leading to localized electronic states that serve as a basis for electrically-induced charge trapping and optically-mediated charge release. Our devices exhibit excellent photo-responsive memory characteristics with a large linear dynamic range of ∼4,700 (73.4 dB) coupled with a low OFF-state current (<4 pA), and a long storage lifetime of over 10 4  s. In addition, the multi-level detection of up to 8 optical states is successfully demonstrated. These results represent a significant step toward the development of future monolayer optoelectronic memory devices. Memory devices are key building blocks of image sensing circuitry. Here, the authors demonstrate a MoS 2 monolayer optoelectronic memory device based on charge trapping and subsequent optically-induced charge release, capable of 12-bit operation.