Search

In this work, we discuss the electrical characteristics of metal-insulator-metal (MIM) structures based on ultra-thin hafnium oxides whose stoichiometry have been modified and a thermal treatment after gate metallization has also been applied. Here, we show that the current-voltage characteristics are improved for the annealed samples in terms of lower gate leakage current densities and higher breakdown electric fields. In addition, the role of the modulation in the oxygen concentration for HfO2 on the MIM's current-voltage, capacitance-voltage, and resistive switching characteristics is also addressed. From these data, a trade-off between current-voltage characteristics and basic memory performance is clearly seen, thus highlighting the importance of combining oxygen modulation and/or post-metallization annealing in HfO2-based MIM structures. Finally, the resistive switching effect is shown in the bipolar mode for some MIM structures and the dominant carrier conduction mechanism (just before the SET condition) is also obtained and related to Poole-Frenkel conduction. [ABSTRACT FROM AUTHOR]

Nanomaterials are a potential alternative to conventional random resistive access memory (ReRAM) in non-volatile memory (NVM) due to their unique electrical and physical properties. Nevertheless, obtaining a specific NVM characteristic [particularly Write-Once-Read-Many (WORM)] using carbon-based electrodes necessitates further assessment. This study proposed a reinvented methodology for TiO 2 -based devices to produce WORM memory behavior using the doctor blade method. A carbon/graphite counter electrode (Gr/Cb) was fabricated and characterized for TiO 2 -based resistive switching devices. Consequently, the Gr/Cb electrode device quickly transitioned from a high to low resistance state, suggesting WORM memory behavior. Approximately 66.7 % improvement (∼1.8 V–∼0.6 V) was observed in the required applied voltage when the active area was reduced, indicating lower power consumption. Overall, this study provided evidence of the approach's feasibility in practical applications, demonstrating lower costs and simplicity. The structure also highlighted the importance of understanding the WORM behavior for effectively utilizing carbon-based electrodes in non-volatile memories. [Display omitted] • Novel carbon-based electrodes were integrated into TiO 2 -based ReRAM devices. • The lowest ON voltage were ∼0.6 V and ∼1.8 V for ITO/TiO 2 /Gr/Cb (pixel) and ITO/TiO 2 /Gr/Cb (strip) memory devices. • WORM behavior was achieved using a TiO 2 -based ReRAM device. • VCM theory could be used to explain the ohmic behaviour and Schottky emission mechanism. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new Furan-based bisphosphoramide displays strong UV light absorption but its Th(IV) complex resists the absorption of UV light. • A UV-light sensor has been demonstrated for Th4+ ions selectively. • The limit of detection (LOD) and limit of quantitation (LOQ) for Th4+ ions are 1.04 x 10-7 M and 3.472 x 10-7 M, respectively. • This salient UV light absorption phenomenon explores the artificial synaptic behavior of the L-Th4+ complex which can have remarkable memory and applications in neuromorphic devices. This article describes the synthesis and photophysical properties of a new furan-based bisphosphoramide ligand (L) and its Th(IV) complex characterized by various analytical and spectroscopic techniques. As expected, L , associated with several double bonds within the structure and the possible π → π* transitions, displays strong absorption in the UV region. Notably, the absorption of UV light decreases significantly in an exclusive manner for the L-Th4+ complex, and such behavior was not observed with most of the transition metals as well as f -metal ions. The ligand-to-metal binding ratio of L-Th4+ was found to be 1:1 through the Job's plot. This photophysical property was successfully explored in the selective determination of Th4+ ions in aqueous solutions. The limit of detection (LOD) for Th4+ and limit of quantitation (LOQ) were determined to be 1.04 x 10-7 M and 3.472 x 10-7 M, respectively. In order to get an insight at the molecular level, a density functional theory (DFT) investigation was performed to comprehend the sensing mechanism and interaction in the detection of Th4+ by L. Furthermore, this salient UV light absorption phenomenon was employed in exploring the artificial synaptic behavior of the L-Th4+ complex which can have remarkable memory and applications in neuromorphic devices. [ABSTRACT FROM AUTHOR]