We report a stacked Y2O3/TiOx resistive random access memory (RRAM) device, showing good high‐temperature switching characteristics of extremely low reset current of 1 μA at 150 °C, large off/on resistance window (>200) at 150 °C, large rectification ratio of ~300 at 150 °C and good current distribution at 85 °C. The good rectifying property, lower high‐temperature sneak current and tighter high‐temperature current distribution can be attributed to the combined results of the oxygen vacancies in TiOx and the related carrier depletion effect.
We investigate a system consisting of multiple ring lasers coupled by a single gain medium. All the ring lasers share a common feedback arm. The output power of an individual laser shows periodic oscillations as a function of time. The periodicity of the oscillation is determined by the ratio of the roundtrip times of the feedback arm and the ring cavity. In the case that two of such ring lasers are coupled, either their oscillation periodicities are synchronized, or the system is bi-stable. In the latter operation regime, the system can act as an optical flip-flop memory whose state be switched by injection of external light. The concept can be extended to multi-state operations; an eight-state optical flip-flop memory is experimentally demonstrated. 相似文献
Ferroelectric memory is one of the most attractive emerging nonvolatile memory. Conventional methods to increase storage density in ferroelectrics include reducing the storage bit size or fabricating 3D stacks. However, the former will face a physical limit finally, and the integration of single-crystalline ferroelectric oxide following the latter still remains a great challenge. Here, a new method is introduced to construct a scroll-like 3D memory structure by self-rolling-up single-crystalline ferroelectric oxides. PbZr0.3Ti0.7O3 single-crystalline thin film is chosen as a prototype and epitaxially grown on another oxide stressor layer with a few lattice-mismatch. Releasing such “Pb(Zr, Ti)O3/stressor” bilayered structure from the substrate induces self-rolling-up due to the internal stress from the lattice-mismatch. High-density information can be written in the form of switched ferroelectric domains on those flat “Pb(Zr, Ti)O3/stressor” membranes via piezoelectric force microscopy. In self-rolling-up membranes, information density can be experimentally enhanced up to 45 times. Theoretically, the freestanding “Pb(Zr, Ti)O3/stressor” membranes have a strongly driven force to self-rolling-up, and the area ratio can enhance 100–450 times, corresponding to an ultra-high density information storage of 102 Tbit In−2. This study provides a new and general method to develop compact, high-density, and 3D memories from oxide materials. 相似文献
The metal oxide heterostructures market is exponentially growing, adhering to the trend of achieving fabrication versatility on a vast range of nonconventional electromagnetic and optical properties. A high degree of substrate tolerance and solution‐phase growth potential promise low‐cost flexible electronics and silicon‐based process compatibility. A molecule‐based complex oxide nanostructured stack integrated in an electro‐optically operable nonvolatile two‐terminal capacitive memory element is proposed. The cell demonstrates a remarkably high > 7 V memory window and write–read times down to 10 ns, promising for reliable high‐speed storage. Molecular orbital occupancy through broadband optical stimulus enables simultaneous phononic addressing and boosts the written information amount by up to 37%, achieving 10+ years storage duration. The resulting nonvolatile memories are the first‐documented complementary metal oxide semiconductor (CMOS)‐compatible long‐term‐retention molecular capacitive cell of its kind, implementing inherent structure‐emerging heat management. Great potential emerges for numerous energy‐inspired innovations, enabling functional oxide–molecular hybrids exploitation as high‐end nonvolatile memory products. 相似文献
Oxide-based ionic conductors have attracted tremendous research interests due to their wide applications in energy storage and conversion devices, such as photovoltaics, fuel cells, batteries, and supercapacitors. Extensive efforts have been undertaken to improve the ionic conductivity of existing materials along with the development of novel conductors. The recent advance of ionic conductors in nanoscale demonstrated their ultra–high ionic conductivity for the promising applications in energy sector. In this work, recent progresses of conventional oxide conductors and the development of novel conductors are reviewed in details. The strategy to exploit the nanoionics of enhancing the ionic conductivity is discussed. Furthermore, the novel applications of nanoionics for the resistive switching memories are summarized. 相似文献
The photorefractive grating generated by two coupled waves produces a rich spatiotemporal dynamics such as those of solitons and chaos. In this paper, the dynamics of grating along with the slow-varying envelope of two coupled waves is studied where the photorefractive-coupling constant is large or more importantly the dynamics is much faster than the photorefractive response time of the material. Under this condition, new solutions of the dynamic grating equations are presented and analytically solved in the form of the Jacobi’s Elliptic functions. The spatiotemporal grating can result in a periodic space-charge field which in turn generates the space charge waves in the periodic case as a result of the spatiotemporal dynamics of the anisotropic two-wave mixing process. The theoretical work of the limiting case is in good agreement with the experimental results using a BaTiO3 crystal. 相似文献
Electrical and optical studies have been carried out on aluminium-modified Ge2Sb2Te5 thin films to check its applicability as an active material in optical and electrical memory storage devices. Five polycrystalline bulk samples were prepared with compositions: Alx(Ge2Sb2Te5)1?x; x = 0, 0.08, 0.14, 0.21, 0.25. Amorphous thin films were deposited from the polycrystalline bulk by thermal evaporation. Temperature-dependent resistance shows the increase in crystallization temperature of Ge–Sb–Te films on aluminium addition. Activation energy for conduction, conductivity, optical band gap, coefficient of refraction and extinction coefficient are studied with respect to Al content in both amorphous and crystalline phases of Ge–Sb–Te alloy films. 相似文献