共查询到16条相似文献,搜索用时 79 毫秒
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多孔硅微腔是采用交替变化脉冲腐蚀电流密度的方法制成的多孔度周期性变化的多孔硅结构.用原子力显微镜(AFM)和扫描电子显微镜(SEM)对多孔硅微腔的侧向解理的截面进行了观测,得到了不同多孔层及其界面处的图像.微腔截面的扫描电镜图像清楚地显现出第Ⅱ型多孔硅微腔的"三明治”结构,即中心发光层被夹在两个Bragg反射镜之间.这些结果表明结合分子束外延技术和电化学腐蚀方法可以很容易得到多孔硅微腔. 相似文献
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详细讨论了两种新的多孔硅发光机制理论(无序Si网络结构和聚硅烷/氢化物发光)以及相应的实验支持。通过分析多孔硅的各种发光机制和多孔硅微结构研究,作者认为多孔硅不是仅有一种发光机制,不同的微结构和成分构成会产生不同的发光机制,其中量子限制效应和聚硅烷/氢化物发光是受到较多实验支持的,分别有微结构和成分决定的发光理论。 相似文献
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使用反射光谱、光致发光光谱和SEM研究了通过脉冲腐蚀形成的多孔硅薄膜的径向折射率、光学和物理厚度。详细分析了沿径向方向多孔硅薄膜的径向折射率(n)和光学厚度(nd)与腐蚀中心之间的关系。实验结果表明:随着远离腐蚀中心,SEM图像表明:多孔硅样品的物理厚度缓慢变小,在腐蚀边缘,在径向58μm距离里,薄膜的物理厚度从2.48μm减少到1.72μm;此外,径向折射率n增加,即多孔度变小,同时,反射光谱强度显示出干涉振荡减弱,这意味着多孔硅薄膜的均匀性和界面的平整度变坏。光致发光谱的包络线显示蓝移的趋势,显示纳米微粒的尺寸减少。多孔硅微腔被制备用来研究多孔硅膜的径向光学特性,结果证实:在腐蚀中心,多孔硅膜的均匀性比边缘好。 相似文献
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阳极氧化多孔氧化铝薄膜(anodicporousaluminafilm,APA)作为模板的应用已引起广泛关注。它的优点在于其主要的特征参数如孔径(1~300nm)、孔长(10~3000nm)及孔密度(108~1011cm-2)都可以用选择不同腐蚀电压的方法来加以控制,孔的长度直径比可达1000以上[1],而且在理想的APA膜中,孔阵列规则排列为蜂巢状六方结构[2]。这一特点为大面积原位合成规则排列纳米量子点/线材料提供了重要保证。考虑到和当前主流硅集成半导体工业相匹配,硅基多孔氧化铝薄膜(Si-basedanodicporousaluminafilm,APA/Si)的应用已见报道[3,4]。我们研究发现当孔径小… 相似文献
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用扫描电镜(SEM)对厚度不同的多孔硅膜的微结构进行了研究。对于23μm厚的多孔硅膜,其横截面微结构好似海底生长的海藻;而对于6μm厚的多孔硅膜,其表面微结构则像龟壳上的裂纹。通过对在不同放大倍数情况下拍摄的多孔硅的SEM图片进行分析,结果表明多孔硅薄膜的这两种微结构都具有分形特征,而且其分形维数为2.3~2.6。利用扩散限制凝聚模型(diffusion limited aggregation)对这两种微结构的形成过程进行了模拟。 相似文献
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用电化学脉冲腐蚀方法制备了多孔硅微腔,讨论了脉冲电化学腐蚀的参数--周期、占空比对多孔硅多层膜制备的影响,并用了以HF酸扩散为基础的多孔硅动态腐蚀机理对实验结果进行解释,认为在用电化学脉冲腐蚀法制备多孔硅微腔的过程中,不但要考虑到HF酸对硅的纵向电流腐蚀,也要考虑到HF酸对多孔硅硅柱的横向浸泡腐蚀.可通过选取合适的周期、占空比,使二者对多孔硅的作用达到适中,以制备出高质量的多孔硅多层膜和微腔.并用正交实验法优化了制备多孔硅微腔的参数,根据优化的实验参数,制备出了发光峰半峰宽为6nm的多孔硅微腔. 相似文献
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Elias Estephan Marie‐Belle Saab Vivechana Agarwal Frédéric J. G. Cuisinier Christian Larroque Csilla Gergely 《Advanced functional materials》2011,21(11):2003-2011
Addressing the surface chemistry of silicon is of fundamental scientific and technical significance due to the wide use of this material in electronics and optics. A novel method of functionalizing silicon (Si) via short peptides with binding specificity for Si is presented. The peptide presenting the highest affinity for Si is identified via phage display technology, and the 12‐mer LLADTTHHRPWT and SPGLSLVSHMQT peptides were found to be specific for the n+‐Si and p+‐Si surfaces, respectively. In our sensing application, the obtained peptides are used as functionalizing linkers to allow porous silicon microcavities to bind biotin and then capture streptavidin. Molecular detection is monitored via reflectometric interference spectra as shifts in the resonance peaks of the cavity structure. An improved streptavidin sensing (21 times lower detection limit) with peptide‐functionalized porous silicon microcavities is demonstrated, compared to sensing performed with devices functionalized with the commonly used silanization method, suggesting that the modification of Si via Si‐specific peptides provides better interface layers for molecular detection. High‐resolution atomic force microscopy images corroborate this result and reveal the formation of ordered nanometer‐sized molecular layers when peptide‐route functionalization is performed. 相似文献
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电化学脉冲腐蚀法制备窄峰发射的多孔硅微腔 总被引:1,自引:0,他引:1
用电化学脉冲腐蚀方法制备了多孔硅微腔 ,讨论了脉冲电化学腐蚀的参数——周期、占空比对多孔硅多层膜制备的影响 ,并用了以 HF酸扩散为基础的多孔硅动态腐蚀机理对实验结果进行解释 ,认为在用电化学脉冲腐蚀法制备多孔硅微腔的过程中 ,不但要考虑到 HF酸对硅的纵向电流腐蚀 ,也要考虑到 HF酸对多孔硅硅柱的横向浸泡腐蚀 .可通过选取合适的周期、占空比 ,使二者对多孔硅的作用达到适中 ,以制备出高质量的多孔硅多层膜和微腔 .并用正交实验法优化了制备多孔硅微腔的参数 ,根据优化的实验参数 ,制备出了发光峰半峰宽为 6 nm的多孔硅微腔 相似文献
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Fransiska S. H. Krismastuti Stephanie Pace Nicolas H. Voelcker 《Advanced functional materials》2014,24(23):3639-3650
A real‐time, sensitive, and selective detection device to monitor the healing status of chronic wounds at the point of care is urgently required to render the management of this disease more effective. The photonic properties of porous silicon resonant microcavity (pSiRM) afford an excellent opportunity to be developed as a highly sensitive optical biosensor to monitor the presence of specific biomarkers found in the wound exudate, such as matrix metalloproteinases (MMPs). In this study, the pSiRM is designed, fabricated, and functionalized using a fluorogenic MMP peptide substrate featuring both a fluorophore and a quencher. The peptide‐functionalized pSiRM is then employed as a fluorescence‐based optical biosensor for MMPs. Active MMPs recognize and cleave the peptide sequence of the substrate, producing an immobilized peptide fragment carrying the fluorophore. The fluorescence intensity of the fluorophore embedded within the pSiRM matrix is enhanced by the photonic structure of the pSiRM compared to other pSi photonic structures. This fluorescence enhancement translates into high sensitivity, enabling detection of MMP‐1 at a limit of detection as low as 7.5 × 10?19 m after only 15 min incubation time. Finally, the biosensor also allows the detection and quantification of the concentration of MMPs in human wound fluid. 相似文献
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使用高分辨电子能量损失谱(HREELS)和紫外光电子能谱(UPS)研究了新腐蚀的多孔硅(PS)样品的电子结构。实验结果表明,从HREELS谱中能量损失阚值测得的PS的能隙移到2.9eV,与文献报道的光激发谱(PLE)结果相近。UPS结果表明PS的费米能级到价带顶的距离不同于单晶Si。结合HREELS和UPS结果可以初步得出PS与Si界面的能带排列。 相似文献
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多孔硅光致发光谱的多峰结构 总被引:2,自引:0,他引:2
基于多孔光致发光的量子限制效应模型,研究了多孔硅发光性质随温度的变化关系.结果表明:多孔硅光致发光谱呈多峰结构,这些分立的发光峰是由多孔硅的本征因素引起的. 相似文献
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A novel material porous silicon is used as diffusion layer in pPEMFC (micro proton eXchange membrane fuel cells) for its loose and porous structure and compatibility with IC process. Study of the formation of porous silicon and metal sputter deposition on the porous silicon is performed. A fabrication process of pPEMFC based on the technology of MEMS and film deposition is presented. 相似文献