共查询到20条相似文献,搜索用时 140 毫秒
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图案化多孔硅是微电子、微机械、光电子器件的重要组成部分.实验以含Si3N4保护层的光刻单晶硅片为基底,采用电化学阳极氧化法制备图案化厚膜多孔硅,分析阳极氧化前后Si3N4保护层表面形貌变化特征和光刻尺寸对图案化多孔硅宽度、膜层厚度的影响规律,表征图案化多孔硅的结构、组成与发光性能.结果表明,氧化前Si3N4保护层局部区域出现枝晶,阳极氧化后形成不均匀孔状结构;制备的图案化多孔硅膜厚62~83μm,其横向扩展程度和膜层厚度均随光刻尺寸增大呈减小趋势;图案化多孔硅微结构含大量不规则裂纹和硅柱,新鲜制备的表面含Si-Hx键,其光致发光峰值波长650nm. 相似文献
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介绍了多孔硅的热导率特性以及孔径、孔隙率、热处理等因素对其影响.分析了目前基于热绝缘的多孔硅制备技术发展现状,着重对阶梯电流法和脉冲电流法进行了介绍和比较, 认为脉冲电流法因为其特殊的优势,将在以后的发展中得到更广泛的应用.多孔硅由于其热绝缘特性以及技术优势,已经在微传感器领域得到广泛的应用. 相似文献
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通过旋涂法,实现了阳极氧化多孔硅和多孔氧化铝与有机发光材料DBO-PPV的复合.发光特性的测试表明,多孔硅与DBO-PPV复合后发光光谱中出现了在多孔硅和DBO-PPV的光致发光谱中都没有的发光峰,被认为是DBO-PPV向多孔硅发生了载流子的转移.而多孔氧化铝/DBO-PPV复合体系的发光特性兼具有多孔氧化铝和DBO-PPV的特征,PL谱呈现多峰的结构(四峰).多孔氧化铝的纳米孔有效地吸附了DBO-PPV分子,抑制了DBO-PPV分子的聚集,使它的禁带宽度变宽,从而使DBO-PPV的发光峰蓝移,蓝移量为90nm. 相似文献
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对硅基锆钛酸铅(PZT)压电薄膜微开关进行了结构和版图设计,根据MEMS加工工艺和标准硅基IC工艺的特点,获得了硅基PZT压电薄膜微悬臂梁结构系统工艺流程中的关键工艺技术和典型工艺条件,对多孔硅的选择性生长进行了较为详细的实验研究,最后成功的制备出硅基PZT压电薄膜微开关样品,这对集成化芯片系统的进一步发展打下了必要的良好的实验基础。 相似文献
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Luca De Stefano Ivo Rendina Luigi Moretti Andrea Mario Rossi 《Materials Science and Engineering: B》2003,100(3):271-274
A porous silicon multilayer, constituted by a Fabry–Pèrot cavity between two distributed Bragg reflectors, is exposed to vapor of several organic species. Different resonant peak shifts in the reflectivity spectra, ascribed to capillary condensation of the vapor in the silicon pores, have been observed. Starting from experimental data, the layer liquid volume fractions condensed in the sensing stack have been numerically estimated. Values ranging between 0.27 (for ethanol) and 0.33 (for iso-propanol) have been found. Time-resolved measurements show that the solvent identification occurs in less then 10 s. 相似文献
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A simple geometry optical sensor based on porous silicon technology is theoretically and experimentally studied. We expose some porous silicon optical microcavities with different porous structures to several substances of environmental interest: Very large red shifts in the single transmission peak in the reflectivity spectrum due to changes in the average refractive index are observed. The phenomenon can be ascribed to capillary condensation of vapor phases in the silicon pores. We numerically compute the peak shifts as a function of the liquid volume fraction condensed into the stack by using the Bruggeman theory. The results presented are promising for vapor and liquid detection and identification. 相似文献
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Atiwongsangthong N 《Journal of nanoscience and nanotechnology》2012,12(8):6602-6607
The purpose of this research, the nanoporous silicon layer were fabricated and investigated the physical properties such as photoluminescence and the electrical properties in order to develop organic vapor sensor by using nanoporous silicon. The Changes in the photoluminescence intensity of nanoporous silicon samples are studied during ultraviolet illumination in various ambient gases such as nitrogen, oxigen and vacuum. In this paper, the nanoporous silicon layer was used as organic vapor adsorption and sensing element. The advantage of this device are simple process compatible in silicon technology and usable in room temperature. The structure of this device consists of nanoporous silicon layer which is formed by anodization of silicon wafer in hydrofluoric acid solution and aluminum electrode which deposited on the top of nanoporous silicon layer by evaporator. The nanoporous silicon sensors were placed in a gas chamber with various organic vapor such as ethanol, methanol and isopropyl alcohol. From studying on electrical characteristics of this device, it is found that the nanoporous silicon layer can detect the different organic vapor. Therefore, the nanoporous silicon is important material for organic vapor sensor and it can develop to other applications about gas sensors in the future. 相似文献
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Kim YY Kim HJ Kim HJ Choi DG Cheng H 《Journal of nanoscience and nanotechnology》2012,12(6):4564-4569
We present a recent experimental study on the application of nanoporous silicon (np-Si) to an optical vapor sensor. We fabricated the micro-system based on a glass-nanoporous silicon layer on a p(+)-type silicon wafer. To check the selectivity and sensitivity of the np-Si layer to organic vapors, we prepared three types of np-Si layer samples--a single layer, distributed Bragg reflector (DBR) layer, and microcavity layer--and investigated its reflectance spectra upon exposure to different concentrations of various organic vapors. When the np-Si layer samples were exposed to the organic vapors, a red-shift occurred in the reflectance spectrum, and we determined that this red-shift can be attributed to the changes in the refractive index induced by the capillary condensation of the organic vapor within the pores of the np-Si layer. The np-Si layer samples showed excellent sensing ability to different types and concentrations of organic vapors. After removing the organic vapors, the reflectance spectrum immediately returned to its original state. 相似文献
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De Stefano L. Moretti L. Lamberti A. Longo O. Rocchia M. Rossi A.M. Arcari P. Rendina I. 《Nanotechnology, IEEE Transactions on》2004,3(1):49-54
The sensing of chemicals and biochemical molecules using several porous silicon optical microsensors, based both on single-layer interferometers and resonant-cavity-enhanced microstructures, is reported. The operation of both families of sensors is based on the variation of the average refractive index of the porous silicon region, due to the interaction with chemical substances either in vapor or liquid state, which results in marked shifts of the device reflectivity spectra. The well established single-layer configuration has been used to test a new chemical approach based on Si-C bonds for covalent immobilization of biological molecules, as probe, in a stable way on the porous silicon surface. Preliminary results on complementary oligonucleotide recognition, based on this technique, are also presented and discussed. Porous silicon optical microcavities, based on multilayered resonating structures, have been used to detect chemical substances and, in particular, flammable and toxic organic solvents, and some hydrocarbons. The results put in evidence the high sensitivity, the reusability, and the low response time of the resonant-cavity-enhanced sensing technique. The possibility of operating at room temperature, of remote interrogation, and the absence of electrical contacts are further advantages characterizing the sensing technique. 相似文献
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Ionic liquids: a new class of sensing materials for detection of organic vapors based on the use of a quartz crystal microbalance 总被引:3,自引:0,他引:3
A QCM device employing ionic liquids as the sensing materials for organic vapors has been developed and evaluated. The sensing mechanism is based on the fact that the viscosity of the ionic liquid membrane decreases rapidly due to solubilization of analytes in the ionic liquids. This change in viscosity, which varies with the chemical species of the vapors and the types of ionic liquids, results in a frequency shift of the corresponding quartz crystal. The QCM sensor demonstrated a rapid response (average response time of less than 2 s) to organic vapors with an excellent reversibility because of the fast diffusion of analytes in ionic liquids. Furthermore, the ionic liquids, with zero vapor pressure and stable chemical properties, ensure a long-term shelf life for the sensor. 相似文献
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Theoretical and experimental studies of a double layer antireflection coating deposited onto silicon wafers have been carried out. Magnesium oxide and cerium oxide fabricated by physical vapor deposition method have been applied as low- and high-refractive index materials. MgF2–CeO2–Si structures exhibited the reflectivity below 3% in the wavelength window from 0.5 μm to 1.2 μm. Theoretical simulations of spectral characteristics of the reflectivity of these coatings have been performed. A good correlation between experimental data and theoretical curves has been observed with the assumption that a thin SiO2 layer of a thickness of 16 nm is formed onto Si substrates. 相似文献
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Xiangyu Jiang Xiqi Zhang Yuchen Wu Yunqi Li Jinhui Pang Haitao Zhang Lei Jiang 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(27)
An artificial organic vapor sensor based on a finite number of 1D nanowires arrays can provide a strategy to allow classification and identification of different analytes with high efficiency, but fabricating a 1D nanowires array is challenging. Here, a coaxial Ag/polymer nanowires array is prepared as an organic vapor sensor with specific recognition, using a strategy combining superwettability‐based nanofabrication and polymeric swelling‐induced resistance change. Such organic vapor sensor containing commercial polymers can successfully classify and identify various organic vapors with good separation efficiency. An Ag/polymer nanowires array with synthetic polyethersulfone polymers is also fabricated, through molecular structure modification of the polymers, to distinguish the similar organic vapors of methanol and ethanol. Theoretical simulation results demonstrate introduction of specific molecular interaction between the designed polymers and organic vapors can improve the specific recognition performance of the sensors. 相似文献
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W. B. Yan Y. Chen H. Chen C. Krusen P. T. Woods 《International Journal of Thermophysics》2008,29(5):1567-1577
Continuous-wave cavity ring-down spectroscopy (CW-CRDS) (using continuous-wave lasers) is now in widespread use for the sensitive
detection of a range of different trace-gas species, including water vapor as a very important trace contaminant in many gases.
It has also now been applied to monitor trace water vapor in a range of matrix gases, including those that are corrosive and
have the potential for spectral interference with the target water-vapor species. The developments that have been carried
out to achieve this will be discussed, and some of the applications, covering single sensors and multi-head sensors, will
be presented. One limitation of the current sensor technology is that it uses mirrors that are highly reflective over a very
restricted spectral range, and this limits a given sensor to the measurement of one or two gaseous species. Measurements of
other species require the mirrors to be changed, as it is not currently practical to obtain mirrors with the required high
reflectivity that also cover a large spectral range. The development of a new type of ring-down cavity that uses uncoated
reflective optics, and which can be used from the ultraviolet to the infrared spectral regions, is presented. Examples of
industrial and scientific applications are also presented. 相似文献
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报道了化学气相沉积金刚石薄膜生长的原位反射率测量,提出了监控金刚石薄膜生长的激光反射多光束干涉的数学模型。通过原位反射率的测量,精确监控了金刚石薄膜的生长厚度,成功地制备了红外增透增,这种方法的测量装置简单、紧凑而且可靠。 相似文献