Chemistry of Luminescent Porous Silicon

本工作的目的是了解多孔硅中发光的起源，并探索这种材料的发光与表面化学的关系。第一个目标将通过测试目前解释多孔硅中光致发光的三个假设来实现。第二个目标将通过观察材料暴露于各种化学试剂（如路易斯酸或碱、电子、空穴或能量转移剂、极性或极化物质）时发生的发射强度、波长和寿命的变化来实现。研究了多孔硅的气相猝灭机理。硅表面化学将通过调整特定吸附剂的淬火响应来发展。多孔硅在化学吸附物存在下改变其荧光颜色和强度的独特能力为气体、液体和生物传感器开辟了一系列可能的应用。此外，在这些条件下，对多孔硅的基本光物理的理解可能会导致全彩平板电致发光显示器的发展。这些潜在的发展可以建立在完善的硅加工技术之上。这项工作的关键贡献在于，它将定义发光多孔硅的化学和光化学反应模式，为此类应用的发展提供设计规则。

The goal of this work is to understand the origin of luminescence in porous silicon, and to explore the relationship between luminescence and surface chemistry of this material. The first goal will be achieved by testing the three current hypotheses explaining photoluminescence in porous silicon. The second goal will be achieved by observing the changes that occur in emission intensity, wavelength, and lifetimes on exposure of the materials to various chemical reagents such as Lewis acids or bases, electron, hole, or energy transfer agents, and polar or polarizable species. The mechanism of luminescence quenching of porous silicon by gas phase species will be studied. The silicon surface chemistry will by developed by tuning the quenching response for specific adsorbates. The unique ability of porous silicon to change its fluorescence color and intensity in the presence of chemical adsorbates opens up a range of possible application for gas, liquid, and biological sensors. In addition, an understanding of the fundamental photophysics of porous silicon under these conditions may lead to the development of full-color flat panel electroluminescence displays. these potential development can build on well- established silicon processing technology. The key contribution of the proposed work is that it will define the chemical and photochemical reactivity patterns of luminescent porous silicon, providing the design rules for the development of such applications.