This review article attempts to provide a comprehensive review of the recent progress in the so-called resistive random access memories (RRAMs) First, a brief introduction is presented to describe the construction and development of RRAMs, their potential for broad applications in the fields of nonvolatile memory, unconventional computing and logic devices, and the focus of research concerning RRAMs over the past decade Second, both inorganic and organic materials used in RRAMs are summarized, and their respective advantages and shortcomings are discussed Third, the important switching mechanisms are discussed in depth and are classified into ion migration, charge trapping/de-trapping, thermochemical reaction, exclusive mechanisms in inorganics, and exclusive mechanisms in organics Fourth, attention is given to the application of RRAMs for data storage, including their current performance, methods for performance enhancement, sneak-path issue and possible solutions, and demonstrations of 2-D and 3-D crossbar arrays Fifth, prospective applications of RRAMs in unconventional computing, as well as logic devices and multi-functionalization of RRAMs, are comprehensively summarized and thoroughly discussed The present review article ends with a short discussion concerning the challenges and future prospects of the RRAMs

Recent progress in resistive random access memories: Materials, switching mechanisms, and performance

The present invention relates to novel organic electroluminescent compounds exhibiting high luminous efficiency, and organic electroluminescent devices comprising the same. The organic electroluminescent compounds according to the invention are represented by Chemical Formula (1):

Novel organic electroluminescent compounds and organic electroluminescent device using the same

Carbon Nanotube Thin Films: Fabrication, Properties, and Applications

Polymer electronic memories: Materials, devices and mechanisms

The present invention relates to compounds of the formula (1) which are suitable for use in electronic devices, in particular organic electroluminescent devices, and to electronic devices which contain these compounds.

Materials for organic electroluminescent devices

Solution processable polymers that can reproducibly form metal filament by applying voltage are investigated for nonvolatile memory application. Up to present, the understanding of materials enabling to make the metal filament has not been well-documented and the vacuum deposition methods were dominantly used in device fabrication. After screening various polymers, we found that only the polymers having two functionalities, the presence of strongly coordinating heteroatom (S or N) with metal ions and the electrical conductivity, showed the reproducible filament formation behavior. Among the polymers screened, the regiorandom poly(3-hexylthiophene) showed the best switching endurance over 30 000 write-read-erase-read cycles without any switching failure.

Metal Filament Growth in Electrically Conductive Polymers for Nonvolatile Memory Application

Well-defined and high-density single-walled carbon nanotube (SWNT) patterns were fabricated using a combination of photolithographic and chemical assembling processes. Unlike the patterned SWNT arrays reported thus far, these SWNT patterned layers have high-density multilayer structures and excellent surface adhesion due to their direct chemical bonding to their substrates, which results in high electrical conductivity. We found that the high-density multilayer SWNT patterns emit electrons under an applied electrical field. The electrical resistivities of the SWNT layers were found to be 5–10Ωcm, with a turn-on electric field of about 3V∕μm at an emission current density of 10μA∕cm2. This technique for fabricating SWNT patterns can be used in the production of field-emission displays and in future device integration requiring carbon nanotubes (CNTs), because it provides large-area patterning of SWNTs with high stability and uniformity.

Electrical and field-emission properties of chemically anchored single-walled carbon nanotube patterns

Single-walled carbon nanotubes (SWNTs) have been chemically attached with high density onto a patterned substrate. To form the SWNT pattern, the substrate was treated with acid-labile group protected amine, and an amine prepattern was formed using a photolithographic process with a novel polymeric photoacid generator (PAG). The polymeric PAG contains a triphenylsulfonium salt on its backbone and was synthesized to obtain a PAG with enhanced efficiency and ease of spin-coating onto the amine-modified glass substrate. The SWNT monolayer pattern was then formed through the amidation reaction between the carboxylic acid groups of carboxylated SWNTs (ca-SWNTs) and the prepatterned amino groups. A high-density multilayer was fabricated via further repeated reaction between the carboxylic acid groups of the ca-SWNTs and the amino groups of the linker with the aid of a condensation agent. The formation of covalent amide bonding was confirmed by X-ray photoelectron spectroscopy (XPS) analysis. Scanning electron microscopy and UV-vis-near-IR results show that the patterned SWNT films have uniform coverage with high surface density. Unlike previously reported patterned SWNT arrays, this ca-SWNT patterned layer has high surface density and excellent surface adhesion due to its direct chemical bonding to the substrate.

Patterning of single-wall carbon nanotubes via a combined technique (chemical anchoring and photolithography) on patterned substrates.

http://phome.postech.ac.kr/user/pnel/publication/44.%20M.-S.%20Jung,%20T.-W.%20Lee,%20J.%20Hyeon-Lee,%20B.%20H.%20Sohn,%20I.-S.%20Jung,%20Polymer,%2047,%202670-2676%20(2006).pdf

Synthesis and characterizations of a polyimide containing a triphenylamine derivative as an interlayer in polymer light-emitting diode

A fuzzy logic controller (FLC) for shooting action is proposed which is one of the fundamental actions for soccer robots. Shooting action is viewed as a posture control problem with such a constraint that the robot should not approach the ball so that the ball moves to the home team area. The FLC consists of two levels: one is the planner level that generates a path to the ball with obstacle avoidance. The other is the motion control level that outputs robot wheel velocities to follow the desired path given the robot's current posture. The effectiveness of the proposed scheme is verified by the real experiments.

Myung-Sup Jung

Papers

Metal Filament Growth in Electrically Conductive Polymers for Nonvolatile Memory Application

Electrical and field-emission properties of chemically anchored single-walled carbon nanotube patterns

Patterning of single-wall carbon nanotubes via a combined technique (chemical anchoring and photolithography) on patterned substrates.

Synthesis and characterizations of a polyimide containing a triphenylamine derivative as an interlayer in polymer light-emitting diode

Fuzzy rule extraction for shooting action controller of soccer robot