title: Upgrading Electroresistive Memory from Binary to Ternary Through Single-Atom Substitution in the Molecular Design.
abstract: 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.
authors: College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Suzhou Nano Science and Technology Institution, Soochow University, Suzhou, 215123, P. R. China.
authors: Xue-Feng
authors: XF
authors: Cheng
authors: College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Suzhou Nano Science and Technology Institution, Soochow University, Suzhou, 215123, P. R. China.
authors: Er-Bo
authors: EB
authors: Shi
authors: College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Suzhou Nano Science and Technology Institution, Soochow University, Suzhou, 215123, P. R. China.
authors: Xiang
authors: X
authors: Hou
authors: College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Suzhou Nano Science and Technology Institution, Soochow University, Suzhou, 215123, P. R. China.
authors: Shu-Gang
authors: SG
authors: Xia
authors: College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Suzhou Nano Science and Technology Institution, Soochow University, Suzhou, 215123, P. R. China.
authors: Jing-Hui
authors: JH
authors: He
authors: College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Suzhou Nano Science and Technology Institution, Soochow University, Suzhou, 215123, P. R. China.
authors: Qing-Feng
authors: QF
authors: Xu
authors: College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Suzhou Nano Science and Technology Institution, Soochow University, Suzhou, 215123, P. R. China.
authors: Hua
authors: H
authors: Li
authors: College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Suzhou Nano Science and Technology Institution, Soochow University, Suzhou, 215123, P. R. China.
authors: Na-Jun
authors: NJ
authors: Li
authors: College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Suzhou Nano Science and Technology Institution, Soochow University, Suzhou, 215123, P. R. China.
authors: Dong-Yun
authors: DY
authors: Chen
authors: College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Suzhou Nano Science and Technology Institution, Soochow University, Suzhou, 215123, P. R. China.
authors: Jian-Mei
authors: JM
authors: Lu
keywords: charge trapping; resistive random-access memory; structure-activity relationships; substituent effects; thiourea; urea