An alternative flexible electrode for dye-sensitized solar cells

With comparable transparency, flexibility, but a better conductivity, metal-mesh based PEN film provides an alternative low-cost electrode material to the conventional ITO/PEN film for flexible solar cell system. In this article, counter electrodes (CEs) prepared by coating metal-mesh/PEN with a mixture of PEDOT:PSS and carbon black nanoparticle (200?C400?nm) were utilized in flexible dye-sensitized solar cells (DSCs). A high efficiency of 5.5?% was achieved with the DSC based on the metal-mesh/PEN CE, rivaling that of the DSC based on ITO/PEN CE.     

二硒化铁/还原氧化石墨烯的制备及其在染料敏化太阳能电池中的应用

通过水热反应合成出二硒化铁/还原氧化石墨烯(FeSe₂/rGO)复合材料, 并将其作为对电极材料应用于染料敏化太阳能电池(DSSC). 利用X射线衍射、拉曼光谱、场发射扫描电子显微镜和高分辨透射电子显微镜对FeSe₂/rGO的结构和形貌进行了表征. 利用循环伏安法、电化学阻抗谱和Tafel曲线测试分析了FeSe₂/rGO对电极的电催化活性. 结果表明: FeSe₂呈纳米棒结构, 长度在100-200 nm之间, 且紧密地附着在rGO 的表面, FeSe₂/rGO对电极对I₃^-的还原具有很好的催化活性. 电池的J-V曲线测试显示: 基于FeSe₂/rGO对电极的DSSC的转换效率达到了8.90%, 相比基于单纯的FeSe₂对电极的DSSC(7.91%)和rGO对电极的DSSC(5.24%)都有了显著提高, 甚至优于铂对电极的DSSC(8.52%).     

量子点液晶显示背光技术

量子点材料兼具极高的色纯度、发光颜色可调以及的荧光量子产率高等特点,已成为显示领域中的明星材料,在提升显示器件的色域方面具有巨大潜力。基于量子点材料的液晶显示背光技术是目前量子点材料在显示器件中的主流应用方向,引起了学术界和工业界的广泛关注。本文将综述量子点液晶显示背光技术的研究进展,主要包括量子点材料的选择、背光结构的应用以及材料复合与封装技术的发展现状,重点介绍了目前产业界广泛关注的量子点光学膜技术,特别是国内自主知识产权的低成本钙钛矿量子点光学膜技术,由于其具备广色域(124%NTSC)、易加工、低成本等特点,已成为具有成长潜力的技术路线。     

Lamp-assisted CVD of carbon micro/nano-structures using metal catalysts and CH2I2 precursor

Carbon micro/nanofibers and nanotubes were deposited via chemical vapor deposition (CVD) using CH₂I₂ precursor and different metal catalysts (Pd, Ni, Fe, Co and Mn) on Si (1 0 0) substrates. A versatile and low-cost IR lamp technique is employed to induce the deposition process. With this method carbon features could be obtained already at temperatures much lower than with common techniques. Palladium metal was deposited by laser-assisted CVD from a liquid solution of the ammine complex and the 3d metals by thermal evaporation. Large-scale periodicity of nano-sized metal catalysts, and subsequently of carbon deposits was obtained by using monolayers of polystyrene microspheres as mask. The carbon structures were analyzed by SEM and micro-Raman spectroscopy.     

直接甲醇燃料电池

文章简要介绍了直接甲醇燃料电池(DMFC)的主要特点、工作原理、应用前景、技术状态及其商业化面临的挑战，开发能够提高甲醇氧化和氧还原动力学速率的低成本电催化剂，制备具有高质子电导率、低甲醇渗透率的电解质膜，实现高性能、长寿命的电极、膜电极制备技术以及系统集成技术的突破对DMFC商业化至关重要。     

碳纳米管薄膜场蒸发效应

在超高真空系统中对基于丝网印刷方法制备的碳纳米管薄膜的场蒸发效应进行实验研究. 实验发现, 碳纳米管薄膜样品存在场蒸发现象, 蒸发阈值场在10.0-12.6 V/nm之间, 蒸发离子流可以达到百皮安量级; 扫描电子显微镜分析和场致电子发射测量结果表明, 场蒸发会使碳纳米管分布变得更加不均匀, 会导致薄膜的场致电子发射开启电压上升(240→300V)、场增强因子下降(8300→4200)、蒸发阈值场上升(10→12.6V/nm), 同时使得薄膜场致电子发射的可重复性明显变好. 场蒸发也是薄膜自身电场一致性修复的表现, 这种修复并非表现在形貌上, 而是不同区域场增强因子之间的差距会越来越小, 这样薄膜场致电子发射的可重复性和稳定性自然会得到改善.     

新型碳材料在钙钛矿太阳电池中的应用研究进展

新型碳材料如石墨烯及其氧化物、碳纳米管、富勒烯及石墨炔等因其优异的热学、力学、电学、光学性能成为了钙钛矿太阳电池研究的又一亮点. 本文总结了新型碳材料在钙钛矿太阳电池对电极、电子传输材料及空穴传输材料中的研究进展, 新型碳材料的引入有效地提高了钙钛矿电池的性能, 为下一步新型碳材料的应用开发以及钙钛矿电池器件的研究提供了新的思路.     

Single-walled carbon nanotubes produced by cw CO2-laser ablation: study of parameters important for their formation

The production of single-walled carbon nanotubes (SWNTs) using the cw CO₂-laser ablation technique is reported. Different metals and metal concentrations in the carbon targets as well as different buffer gases and gas pressures have been used in order to study their influence on the formation of SWNTs. It is shown that the conditions near the evaporation zone, i.e. especially the local temperature environment induced by the laser radiation as well as the used metals play a key role in the formation process of SWNTs. Employing a very simple experimental setup the cw CO₂-laser ablation technique easily provides the environment favorable for the growth of high quality SWNT material under a wide range of experimental conditions.     

Effect of purification on the electron structure and field emission characteristics of a carbonaceous material containing single-wall carbon nanotubes

A carbonaceous material containing single-wall carbon nanotubes (SWNTs) has been synthesized by arc-discharge evaporation of graphite with a catalytic additive of nickel and cobalt powders. The synthesized SWNTs were purified from an amorphous carbon component (soot) and the catalyst particles by boiling in nitric acid. A comparison of the X-ray fluorescence spectra measured before and after this treatment showed that acid etching significantly decreased the content of soot in the material. The material enriched with SWNTs is characterized by a reduced threshold for the appearance of the field emission current, which is explained by a decrease in the screening effect of soot. The current-voltage characteristics of SWNTs exhibit a hysteresis, which is suggested to be due to the adsorption of molecules and radicals on the surface and at the ends of carbon nanotubes.     

Large-scale molecular dynamics simulations of high energy cluster impact on diamond surface

Large-scale molecular dynamics simulations with high acceleration energy on a diamond surface were performed in order to investigate the surface erosion process. Accelerated argon or CO₂ clusters (∼960 atoms, 100 keV/cluster) impacted on the (111) surface of diamond which consisted of more than 1,000,000 carbon atoms. A typical hemispherical crater appeared about 0.7 ps after the impact, and two or three-layered shockwaves were formed and propagated to certain directions, but the crater was immediately filled up with the fluidized hot carbon material due to the collective elastic recovery before the reflection of the shockwave. The impact energy of the cluster was at first transferred mainly as kinetic energy of the diamond surface in a short time, and the potential energy was activated later. The activated carbon and oxygen atoms from the impact cluster stimulated the evaporation from the diamond surface for the CO₂ cluster impact while the evaporation seemed to be suppressed by the argon atoms themselves for the argon cluster impact. Received 22 November 2000     

Low-cost multiple-walled carbon nanotubes absorber for passively Q-switched and mode-locked Nd:YVO4 laser

A low-cost multiple-walled carbon nanotubes/polyvinyl alcohol (MWCNTs/PVA) absorber was fabricated by the characteristics of high viscosity in large molecule PVA aqueous solution and vertical evaporation technique. Sandwich structured MWCNT/PVA absorber was constructed by a piece of MWCNT absorber, a piece of round quartz and a piece of reflective mirror. We exploited it to realize Q-switched mode locking operation in a diode-pumped Nd:YVO₄ laser. The maximum average output power is about 630 mW.     

Biomass waste-derived activated carbon for the removal of arsenic and manganese ions from aqueous solutions

The goal of this study is to investigate the preparation of low-cost activated carbon from bean pods waste and to explore their potential application for the removal of heavy metals from aqueous solutions. Conventional physical (water vapor) activation was used for synthesizing the adsorbent. The obtained carbon was employed for the removal of As (III) and Mn (II) from aqueous solutions at different initial concentrations and pH values. Adsorption for both ions follows Langmuir-type isotherm, the maximum loading capacities for arsenic (III) and Mn (II) ions being 1.01 and 23.4 mg g⁻¹, respectively. According to the experimental data, it can be inferred that the basic character of the surface, i.e. the high content of basic groups, favors adsorption of ions. Arsenic adsorption capacity on the carbon obtained from agricultural waste was found to be similar to this of more expensive commercial carbons showing high adsorption capability. Regarding manganese adsorption, herein obtained carbon presented higher uptake adsorption than that of activated carbons reported in the literature.     

多壁碳纳米管外壁高温蒸发的分子动力学模拟

采用经典分子动力学（MD）方法,使用EDIP（environment-dependent interatomic potential)势描述C纳米管内C原子之间相互作用,对多壁C纳米管由于Stone-Wales缺陷引起外层管高温剥落蒸发现象进行了计算模拟.研究结果表明,高温下多壁C纳米管外层管Stone-Wales缺陷处C原子剧烈振动导致C—C键断裂形成悬键,并逐渐向四周扩散导致外层管剥落蒸发.利用Lindemann指数作为判据,得出多壁C纳米管外层管出现剥落蒸发的温度为2290 K左右,与Huang Jianyu等实验中观测到多壁C纳米管外层管剥落蒸发现象产生的温度2000 ℃基本一致. 关键词： 多壁C纳米管 分子动力学 Stone-Wales缺陷 剥落蒸发     

Relatively low temperature synthesis of graphene by radio frequency plasma enhanced chemical vapor deposition

We present a simple, low-cost and high-effective method for synthesizing high-quality, large-area graphene using radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) on SiO₂/Si substrate covered with Ni thin film at relatively low temperatures (650 °C). During deposition, the trace amount of carbon (CH₄ gas flow rate of 2 sccm) is introduced into PECVD chamber and the deposition time is only 30 s, in which the carbon atoms diffuse into the Ni film and then segregate on its surface, forming single-layer or few-layer graphene. After deposition, Ni is removed by wet etching, and the obtained single continuous graphene film can easily be transferred to other substrates. This investigation provides a large-area, low temperature and low-cost synthesis method for graphene as a practical electronic material.     

Hard carbons derived from pine nut shells as anode materials for Na-ion batteries

Hard carbons as promising anode materials for Na-ion batteries(NIBs) have captured extensive attention because of their low operation voltage, easy synthesis process, and competitive specific capacity. However, there are still several disadvantages, such as high cost and low initial coulombic efficiency, which limit their large-scale commercial applications.Herein, pine nut shells(PNSs), a low-cost biomass waste, are used as precursors to prepare hard carbon materials. Via a series of washing and heat treatment procedures, a pine nut shell hard carbon(PNSHC)-1400 sample has been obtained and delivers a reversible capacity of around 300 mAh/g, a high initial coulombic efficiency of 84%, and good cycling performance. These excellent Na storage properties indicate that PNSHC is one of the most promising candidates of hard carbon anodes for NIBs.     

Highly crystallized sputtered silicon with textured morphology for thin-film solar cells

A light-trapping structure with textured morphology for thin-film solar cell is demonstrated in this paper. It is fabricated through Al evaporation, and has a root-mean-roughness (Rms) of about 120 nm and lateral width of about 1 μm for single bulge. A Mo layer is introduced to be a barrier layer. Subsequently sputtered amorphous silicon film is 100% crystallized by Cu induced crystallization. Reflectivity of samples with different silicon thickness is studied to reveal the light-trapping efficiency and the reflectivity as low as 10% is obtained with only 840 nm thick silicon film. This is a low-cost structure promising for future thin-film solar cells with high efficiency.     

Wall paper single-walled carbon nanotubes absorber for passively mode-locked Nd: GdVO4 laser

A novel and low-cost wall paper single-walled carbon nanotubes (SWCNTs) absorber was fabricated by high viscosity of polyvinyl alcohol (PVA) aqueous solution and vertical evaporation technique. Sandwich structure wall paper SWCNT (SSWA-SWCNT) absorber was constructed by a piece of wall paper SWCNT absorber, a piece of round quartz and an output coupler mirror. We exploited it to realize mode locking operation in a diode-pumped Nd: GdVO₄ laser. A pulse duration of 9.6 ps was produced with an average power of 870 mW. The stable mode locking operation was obtained when the average power is less than 300 mW.     

Fabrication of marker area to align TEM tomographic tilt series of rod-shaped specimens

In this study, we present a new method for placing markers for alignment of tomographic tilt-series of rod-shaped specimen before 3D reconstructions. By this method, markers (gold nanoparticles) were placed only on the carbon layer (referred to as the "marker area") deposited for protecting the specimen surface against ion beam irradiation; this placement was achieved by vacuum evaporation of gold with the help of a mask fabricated adjacent to the specimen. Experimental results showed that the use of the proposed method facilitates the identification of the markers in the alignment process, because the image of the marker area consists of simple high-contrast images of the gold nanoparticles on the carbon layer. The performance of the proposed method was successfully verified experimentally by applying it to a high-density Au/SiO? nanocomposite material as a test specimen.     

CMOS传感器紫外敏化膜层的厚度优化及其光电性能测试

采用真空热阻蒸方式在CMOS图像传感器感光面上镀制不同厚度性比价高的Lumogen薄膜.研究发现不同Lumogen薄膜厚度的CMOS传感器的暗电流噪声未发生明显变化,说明真空热蒸发方式对互补金属氧化物半导体器件本身未造成热损伤;光响应非均匀度随膜厚增加而增大;动态范围却随膜厚增加而减小;量子效率随膜厚增加呈现先增大后减小.同时,研究发现敏化膜层最佳厚度为389nm,此时CMOS传感器的量子效率提高了10%,且光响应非均匀度,动态范围均在相对较好的范围内.     

Substrate pre-treatment of flexible material for printed electronics with carbon nanotube based ink

In this work, an innovative solution was developed in order to make paper-based material, used traditionally in the packaging and labelling industries, compatible with the printing of functional conductive inks. In order to avoid the deterioration of the ink functionalities due to different paper properties, a UV-curing inkjettable primer layer was developed. This pre-treatment enables homogeneous surface properties such as smoothness, absorption capacity and surface energy to be obtained, for almost all the examined substrates. To confirm the positive impact of such pre-treatment, conductivity has been measured when using a new conductive ink, combining the processability of the PEDOT-PSS conductive polymer with the high electrical properties of carbon nanotubes (CNTs). Significant improvement has been measured for all paper materials and similar conductivity (close to reference PET film) has been obtained whatever the substrate involved. This pre-treatment now makes it possible to consider paper-based material as a potential substrate for printed electronics. In this case, the substrate adaptation technique offers an innovative solution to produce low-cost and flexible electronics.