锂离子电池硅负极表面改性的研究进展

硅由于具有高的理论比容量、低的脱嵌锂电位、储量丰富等优势已成为当前高能量密度锂离子电池重要开发的高性能负极材料，但硅负极较大的体膨胀效应和较低的电导率等问题限制硅负极在商业中进一步的应用。针对硅负极材料发展所面临的问题，本文着重从硅的表面改性包括表面包覆、表面功能化、人造固相电解质膜等技术展开综述，分析了这些改性策略及电化学性能改进机理，并对硅表面改性技术进一步发展做了简单展望，旨在开发出高能量密度动力锂电池用关键硅负极材料。     

Pulsed Anodic Anodisation of Porous Silicon Films

Porous Silicon is conventionally made by dc anodisation of silicon. In this paper we have studied the luminescence of porous silicon made by pulsed anodisation as a function of duty cycle and HF concentration. Specifically we show for the first time that the luminescence can be tuned over a wide range in energy.     

CVD法氮化硅薄膜制备及性能

氮化硅薄膜是一种重要的薄膜材料,具有优秀的光电性能,钝化性能和机械性能,将在微电子,光电和材料表面改性领域获得广泛应用,本文着重评述了制备氮化硅薄膜的几种化学相沉积方法和一些性能。     

Evaluation of optical and electronic properties of silicon nano-agglomerates embedded in SRO: applying density functional theory

In systems in atomic scale and nanoscale such as clusters or agglomerates constituted by particles from a few to less than 100 atoms, quantum confinement effects are very important. Their optical and electronic properties are often dependent on the size of the systems and the way in which the atoms in these clusters are bonded. Generally, these nanostructures display optical and electronic properties significantly different to those found in corresponding bulk materials. Silicon agglomerates embedded in silicon rich oxide (SRO) films have optical properties, which have been reported to be directly dependent on silicon nanocrystal size. Furthermore, the room temperature photoluminescence (PL) of SRO has repeatedly generated a huge interest due to its possible applications in optoelectronic devices. However, a plausible emission mechanism has not been widely accepted in the scientific community. In this work, we present a short review about the experimental results on silicon nanoclusters in SRO considering different techniques of growth. We focus mainly on their size, Raman spectra, and photoluminescence spectra. With this as background, we employed the density functional theory with a functional B3LYP and a basis set 6-31G* to calculate the optical and electronic properties of clusters of silicon (constituted by 15 to 20 silicon atoms). With the theoretical calculation of the structural and optical properties of silicon clusters, it is possible to evaluate the contribution of silicon agglomerates in the luminescent emission mechanism, experimentally found in thin SRO films.     

Nanoarchitectonics: Complexes and Conjugates of Platinum Drugs with Silicon Containing Nanocarriers. An Overview

The development in the area of novel anticancer prodrugs (conjugates and complexes) has attracted growing attention from many research groups. The dangerous side effects of currently used anticancer drugs, including cisplatin and other platinum based drugs, as well their systemic toxicity is a driving force for intensive search and presents a safer way in delivery platform of active molecules. Silicon based nanocarriers play an important role in achieving the goal of synthesis of the more effective prodrugs. It is worth to underline that silicon based platform including silica and silsesquioxane nanocarriers offers higher stability, biocompatibility of such the materials and pro-longed release of active platinum drugs. Silicon nanomaterials themselves are well-known for improving drug delivery, being themselves non-toxic, and versatile, and tailored surface chemistry. This review summarizes the current state-of-the-art within constructs of silicon-containing nano-carriers conjugated and complexed with platinum based drugs. Contrary to a number of other reviews, it stresses the role of nano-chemistry as a primary tool in the development of novel prodrugs.     

The Effect of Reducing and Oxidizing Gases and Molten Slag and Alkalis on the Properties and Resistance of Nitride-Based Refractory Materials

Silicon carbide refractory materials and specimens of silicon nitride and silicon oxynitride are tested under high-temperature attack from reducing (H₂ and CO) and oxidizing gases (O₂, air) and from molten slag, alkalis, and iron. It is shown that nitride-based refractory materials are prone to change their properties, structure, and resistance when exposed to molten slag, iron, and alkalis. Silicon oxynitride and silicon nitride resist attack from carbon monoxide and alkali and provide protection to silicon carbide used as the refractory lining for blast furnaces.     

Silicon Nitride and Related Materials

Silicon nitride has been researched intensively, largely in response to the challenge to develop internal combustion engines with hot-zone components made entirely from ceramics. The ceramic engine programs have had only partial success, but this research effort has succeeded in generating a degree of understanding of silicon nitride and of its processing and properties, which in many respects is more advanced than of more widely used technical ceramics. This review examines from the historical standpoint the development of silicon nitride and of its processing into a range of high-grade ceramic materials. The development of understanding of microstructure–property relationships in the silicon nitride materials is also surveyed. Because silicon nitride has close relationships with the SiAlON group of materials, it is impossible to discuss the one without some reference to the other, and a brief mention of the development of the SiAlONs is included for completeness.     

Colloidal solutions of luminescent porous silicon clusters with different cluster sizes

Silicon nanocrystals (Si-ncs) are promising for biological studies due to their supposed low cytotoxicity, good biocompatibility and biodegradability in living organisms. However, the bioresearchers'' focus on Si-ncs has lasted only for a few recent years, and detailed studies of the interaction of various types of Si-ncs with biological environment are still rare. Suitable size and solubility of the Si-ncs in water-based isotonic solutions are important towards bringing the nanocrystals inside the living cells. We have prepared colloidal solutions of luminescent porous silicon of different cluster sizes in methanol, water and phosphate-buffered saline (PBS). By combination of ultrasonic treatment with filtration, we have obtained two different silicon cluster sizes in methanol (120 and 525 nm) and three different cluster sizes (85, 210 and 1,500 nm) in PBS. Nanoclusters of heavily oxidized porous silicon are hydrophilic and well soluble in water and/or PBS. They can be further used for studies on the biocompatibility of these materials and may be potentially employed as luminescent markers in living cells in biological research.

PACS

78.67.Rb; 78.67.-n; 87.85.Qr; 87.85.Rs; 81.07.-b     

Grain boundary glasses in silicon nitride: A review of chemistry,properties and crystallisation

Silicon nitride for engineering applications is densified by liquid phase sintering using oxide additives such as yttria and alumina. The oxynitride liquid remains as an intergranular glass. This paper provides a review of microstructural development in silicon nitride, grain boundary oxynitride glasses and effects of chemistry on properties. Nitrogen increases T_g, viscosities, elastic moduli and microhardness. These property changes are compared with known effects of grain boundary glass chemistry in silicon nitride ceramics where significant improvements in fracture resistance of silicon nitride can be achieved by tailoring the intergranular glass chemistry.Crystallisation of the grain boundary Y–Si–Al–O–N glass phase can improve properties. Nucleation and crystallisation of a Y–Si–Al–O–N glass, similar to that found in grain boundaries of silicon nitride densified with yttria and alumina, can be optimised to form different Y-disilicate polymorphs at different temperatures. One solution to provide a single disilicate phase over a range of temperatures is discussed.     

四氯化硅和四氟化硅的研究比较

SiCl4主要是作为改良西门子法生产多晶硅的副产物得到,SiF4主要是作为磷肥工业的副产物氟硅酸分解得到,但是二者纯度都不能满足生产多晶硅的要求,需进行分离纯化得到高纯物质。本文针对SiCl4和SiF4的物化性质、合成工艺、精制方法、应用前景等方面做了探讨和比较,指出SiF4比SiCl4更具应用前景。     

Removal of Iron from Solar Grade Silicon (SoG-Si) Cutting Slurry Waste by Ultrasound-Assisted Leaching with Dilute Sulfuric Acid

Silicon - Recovering silicon from hazardous solar grade silicon (SoG-Si) cutting slurry waste generated in silicon wafer production is of great significance, but it is distinctly important to...     

High-performance Multicrystalline Silicon Ingots Assisted by Recycled Multicrystalline Silicon Block Tailing as Seeds

Silicon - Nowadays, casted multicrystalline silicon is the most important material in photovoltaic industry. In order to reduce the cost of silicon ingots, the recycle of silicon ingot tailings is...     

The Potential use of Silicon Isotope Composition of Biogenic Silica as a Proxy for Environmental Change

Silicon isotope geochemistry is a relatively new branch of environmental change research. Here we review the recent developments in the preparation of materials, analytical methods and applications of stable silicon isotope geochemistry in the most common types of biogenic silica currently being analysed. These materials are: diatom, radiolarian and siliceous sponges in lake and ocean sediments and plant phytoliths which are preserved in soils. Despite analyses of Si isotopes being carried out on rocks and minerals since the 1950's and the increasingly widespread use of Si isotopes since the 1990's, to date only a relatively small number of studies have applied Si isotope ratios to environmental change. In lake and ocean sediments the analysis of Si isotope ratios from biogenic materials has the potential to provide an important source of palaeoenvironmental information, especially where carbonates are not preserved. In plants and soils few studies have used Si isotopes, but important advances have recently been made in the understanding within plant fractionations. These may be useful in the application of Si isotopes in phytoliths to archaeological and palaeoenvironmental contexts.     

Aluminum Nanoparticles Passivation of Multi-Crystalline Silicon Nanostructure for Solar Cells Applications

Silicon - In this paper, we demonstrated that aluminum films deposited on the front surface of multi-crystalline silicon (mc-Si) provide excellent surface passivation and high electronic quality of...     

Silicon Application Increases Biomass Yield in Sunflower by Improving the Photosynthesizing Leaf Area

Silicon - Sunflower is an oilseed plant important for food and biodiesel production. One cheap way to increase sunflower production is by the application of silicon (Si), which has shown to be...     

Separation of Si and SiC from Photovoltaic Industry Waste. Recycling of SiC in Production of Cu2O-SiC Powder

Silicon - Silicon ingot cutting process generates slurry waste which mainly contains lubricant oil, silicon and silicon carbide particles. In this study, slurry waste was the subject of a primary...     

Effect of Additives on Making Texture Surface on Multicrystalline Silicon Wafer by Diamond Wire Sawing

Silicon - In the production of multicrystalline silicon solar cell, diamond wire sawing method (DWS) is an important technique, which has already completely replaced multiwire slurry sawing (MWSS)...     

Characterization of polydihydrosilane by SEC-MALLS and viscometry

Silicon hydride compounds consisting of silicon and hydrogen constitute a fascinating class of silicon-based polymers because of their ability to form high-quality silicon film by solution-based process. In this study, we synthesize polydihydrosilane by photo-induced ring-opening polymerization of cyclopentasilane, and determine the molar mass, radius of gyration, and intrinsic viscosity of it in cyclohexene by size-exclusion chromatography combined with multi-angle laser light scattering and viscometry. It was found that the molar mass of polydihydrosilane ranges broadly from 10² to 10⁶ g/mol. Both the intrinsic viscosity and radius of gyration exhibited a scaling behavior with respect to the molar mass with the intrinsic viscosity exponent α = 0.206 and radius of gyration exponent ν = 0.410. Classification of the polymer structure based on the α value suggests that the polydihydrosilane forms a branched-chain structure with a particle-like compact shape rather than a straight chain.     

Optical,Morphological, and Structural Properties of Tablets Obtained from Porous Silicon

Silicon - Porous silicon (PS) is a material with a great interest due to its optical (photoluminescent) and chemical (reactive surface) properties, for this reason, it is important to find new ways...     

Experimental Study on the Interaction Between Al and P in Si Solution

Silicon - The effect of impurity interactions on impurity removal efficiency in metallurgical grade silicon (MG-Si) was studied and analyzed to provide a new idea for removing impurities from...