Chemistry of Luminescent Porous Silicon

这项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之间的关系。第一个目标将通过测试解释多孔硅中光致发光的三个电流假说来实现。第二个目标将通过观察材料暴露在各种化学试剂如路易斯酸或碱、电子、空穴或能量转移剂以及极性或极化物种时在发射强度、波长和寿命方面发生的变化来实现。研究了气相物种对多孔硅发光猝灭的机理。硅表面化学将通过调节特定吸附物的猝灭响应来发展。多孔硅在化学吸附体存在的情况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领域。此外，对多孔硅在这些条件下的基本光物理的了解可能会导致全色平板电致发光显示器的发展。这些潜在的发展可以建立在成熟的硅加工技术的基础上。这项工作的主要贡献是，它将定义发光多孔硅的化学反应和光化学反应模式，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.