共查询到15条相似文献,搜索用时 78 毫秒
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实验研究了无光照情况下多孔硅制备中不同单羟基正醇对形貌的影响。实验结果表明,随着醇碳链的增长,多孔硅孔密度减小,枝杈变长,枝杈的尖端变得尖锐。在孔的生长过程中,十字枝杈首先沿着晶格方向快速生长,然后晶格方向的生长速率减小,而非晶格方向则持续生长直到空穴耗尽。本实验增进了对硅溶解动力学中醇作用机理的理解。 相似文献
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在可见光谱内,多孔硅的发光现象及其广阔的应用前景激发了人们对这种潜在光电子学材料的巨大研究兴趣。本文介绍了多孔硅的结构、制备方法和形成原理,着重从纳米结构量子尺寸效应的角度,讨论了多孔硅的能带展宽现象和可见光的发射机制,并评述了这种材料在实际应用中的重要价值与原型器件的发展状况。 相似文献
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Anne M. Ruminski Matthew M. Moore Michael J. Sailor 《Advanced functional materials》2008,18(21):3418-3426
One‐dimensional photonic crystals constructed from multilayered stacks of porous Si are used as sensors for gas‐phase volatile organic compounds (VOCs). The ability of a double‐stack structure to provide compensation for drift due to changing relative humidity (RH) is investigated. In this approach, two separate photonic crystals (dielectric stacks) are etched into a crystalline Si substrate, one on top of the other. The top stack is chemically modified to be hydrophobic (by hydrosilylation with dodecene) and the bottom stack is made hydrophilic (by hydrosilylation with undecylenic acid). It is shown that the optical spectrum of the double‐stack structure provides an effective means to discriminate VOCs from water vapor. In this approach, shifts in the peak frequencies from both photonic crystals are measured simultaneously. Because the two stacks respond differently to water and to VOC, the effect of changing humidity can be nulled by calculating the weighted difference between the two peak frequencies. Reliable determination of the concentration of VOC vapor in nitrogen over a range of RH values (25% < RH < 75%) is demonstrated. The ability of the double‐stack structure to discriminate between water vapor and VOCs is quantified for four different VOCs: toluene, dimethyl methylphosphonate (DMMP), heptane, and ethanol. 相似文献
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