There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

In this critical review, metal oxides-based materials for electrochemical supercapacitor (ES) electrodes are reviewed in detail together with a brief review of carbon materials and conducting polymers. Their advantages, disadvantages, and performance in ES electrodes are discussed through extensive analysis of the literature, and new trends in material development are also reviewed. Two important future research directions are indicated and summarized, based on results published in the literature: the development of composite and nanostructured ES materials to overcome the major challenge posed by the low energy density of ES (476 references).

/pdf/a-review-of-electrode-materials-for-electrochemical-2cok5em0bo.pdf

A review of electrode materials for electrochemical supercapacitors

1. Introduction 20642. Synthesis of Magnetic Nanoparticles 20662.1. Classical Synthesis by Coprecipitation 20662.2. Reactions in Constrained Environments 20682.3. Hydrothermal and High-TemperatureReactions20692.4. Sol-Gel Reactions 20702.5. Polyol Methods 20712.6. Flow Injection Syntheses 20712.7. Electrochemical Methods 20712.8. Aerosol/Vapor Methods 20712.9. Sonolysis 20723. Stabilization of Magnetic Particles 20723.1. Monomeric Stabilizers 20723.1.1. Carboxylates 20733.1.2. Phosphates 20733.2. Inorganic Materials 20733.2.1. Silica 20733.2.2. Gold 20743.3. Polymer Stabilizers 20743.3.1. Dextran 20743.3.2. Polyethylene Glycol (PEG) 20753.3.3. Polyvinyl Alcohol (PVA) 20753.3.4. Alginate 20753.3.5. Chitosan 20753.3.6. Other Polymers 20753.4. Other Strategies for Stabilization 20764. Methods of Vectorization of the Particles 20765. Structural and Physicochemical Characterization 20785.1. Size, Polydispersity, Shape, and SurfaceCharacterization20795.2. Structure of Ferro- or FerrimagneticNanoparticles20805.2.1. Ferro- and Ferrimagnetic Nanoparticles 20805.3. Use of Nanoparticles as Contrast Agents forMRI20825.3.1. High Anisotropy Model 20845.3.2. Small Crystal and Low Anisotropy EnergyLimit20855.3.3. Practical Interests of Magnetic NuclearRelaxation for the Characterization ofSuperparamagnetic Colloid20855.3.4. Relaxation of Agglomerated Systems 20856. Applications 20866.1. MRI: Cellular Labeling, Molecular Imaging(Inﬂammation, Apoptose, etc.)20866.2.

Magnetic Iron Oxide Nanoparticles: Synthesis, Stabilization, Vectorization, Physicochemical Characterizations, and Biological Applications

[Liu, Chang; Li, Feng; Ma, Lai-Peng; Cheng, Hui-Ming] Chinese Acad Sci, Inst Met Res, Shenyang Natl Lab Mat Sci, Shenyang 110016, Peoples R China.;Cheng, HM (reprint author), Chinese Acad Sci, Inst Met Res, Shenyang Natl Lab Mat Sci, 72 Wenhua Rd, Shenyang 110016, Peoples R China;cheng@imr.ac.cn

Advanced Materials for Energy Storage

Microelectronic devices with high integration level and functional complexity are always requiring larger diameter and more perfect Czochralski (CZ) silicon wafers. Therefore, the defects, playing the key role in the quality control of silicon materials, have to be well controlled during crystal growth and device fabrication. Co-doping nitrogen (N), germanium (Ge) or carbon (C) into CZ silicon to control defect dynamics and to change defect evolution, so-called “impurity engineering”, has been developed in recent years, and has been widely applied in the fabrication of higher quality CZ silicon used for microelectronics nowadays. This article is to present an overview of the current status of impurity engineering in CZ silicon, based on the co-doping technologies of N, Ge and C. The fundamental properties of these three co-dopants and their interaction with point defects in CZ silicon are firstly introduced. The bulk of the article is focused on the effects of co-dopants on the formation of oxygen precipitates related to internal gettering (IG) of devices for metal contaminants, and voids associated with the gate oxide integrity (GOI) of devices in CZ silicon. Finally, the improvement of CZ silicon mechanical strength by co-doping technology is described.

Impurity engineering of Czochralski silicon

Self-Powered FA0.55MA0.45PbI3 Single-Crystal Perovskite X-Ray Detectors with High Sensitivity

By indentation at room temperature followed by annealing at high temperatures, the pinning effect of nitrogen on dislocations in nitrogen-doped Czochralski silicon (NCZ Silicon) has been studied. Experimental results showed that dislocations in NCZ Silicon moved slower and shorter than those in common Czochralski silicon (CZ Silicon) during the annealing. The results also indicated that the activation energy of the dislocations in NCZ Silicon was higher than that in CZ Silicon. The stress relaxing mechanism is discussed.

Effects of nitrogen on dislocations in silicon during heat treatment

Developing a low-cost, room-temperature operated and complementary metal-oxide-semiconductor (CMOS) compatible visible-blind short-wavelength infrared (SWIR) silicon photodetector is of interest for security, telecommunications, and environmental sensing. Here, we present a silver-supersaturated silicon (Si:Ag)-based photodetector that exhibits a visible-blind and highly enhanced sub-bandgap photoresponse. The visible-blind response is caused by the strong surface-recombination-induced quenching of charge collection for short-wavelength excitation, and the enhanced sub-bandgap response is attributed to the deep-level electron-traps-induced band-bending and two-stage carrier excitation. The responsivity of the Si:Ag photodetector reaches 504  mA· W−1 at 1310 nm and 65  mA ·W−1 at 1550 nm under −3  V bias, which stands on the stage as the highest level in the hyperdoped silicon devices previously reported. The high performance and mechanism understanding clearly demonstrate that the hyperdoped silicon shows great potential for use in optical interconnect and power-monitoring applications.

/pdf/visible-blind-short-wavelength-infrared-photodetector-with-4mb1p9m6c1.pdf

Deren Yang

Papers

Impurity engineering of Czochralski silicon

Self-Powered FA0.55MA0.45PbI3 Single-Crystal Perovskite X-Ray Detectors with High Sensitivity

Effects of nitrogen on dislocations in silicon during heat treatment

Visible-blind short-wavelength infrared photodetector with high responsivity based on hyperdoped silicon

13.7% Efficiency graphene–gallium arsenide Schottky junction solar cells with a P3HT hole transport layer