Upgrading Electroresistive Memory from Binary to Ternary Through Single-Atom Substitution in the Molecular Design

作者：Cheng, Xue-Feng; Shi, Er-Bo; Hou, Xiang; Xia, Shu-Gang; He, Jing-Hui^*; Xu, Qing-Feng; Li, Hua; Li, Na-Jun; Chen, Dong-Yun; Lu, Jian-Mei^*

来源：Chemistry-An Asian Journal, 2017, 12(1): 45-51.

DOI：10.1002/asia.201601317

• charge trapping
• resistive random-access memory
• structure-activity relationships
• substituent effects
• thiourea
• urea

Herein, two molecules based on urea and thiourea, which differ by only a single atom, were designed, successfully synthesized, and fabricated into resistive random-access memory devices (RRAM). The urea-based molecule showed binary write-once-read-many (WORM) storage behavior, whereas the thiourea-based molecule demonstrated ternary storage behavior. Atomic-force microscopy (AFM) and X-ray diffraction (XRD) patterns show that both molecules have smooth morphology and ordered layer-by-layer lamellar packing, which is beneficial for charge transportation and, consequently, device performance. Additionally, the optical and electrochemical properties indicate that the thiourea-based molecule has a lower bandgap and may be polarized by trapped charges, thus the formation of a continuous conductive channel and electric switching occurs at lower bias voltage, which results in ternary WORM behavior. This study, together with our previous work on single-atom substitution, may be useful to tune and improve device performance in the future design of organic memory.

• 出版日期2017-1
• 单位苏州大学