MRI-R2: Acquisition of Equipment for Rare Earth Spectroscopic Studies of Sol-Gel Glass Structure

Davidson College, Davidson NC

Investigators

Abstract

0959552 Boye Davidson College Technical Summary: This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Sol-gel derived glass containing fluorescing rare earth (RE) ions are potentially useful in applications such as lasers, optical sensors, and fiber optic and photonic devices. However, the optical behavior of RE-doped sol-gel glasses is not yet fully understood. The work proposed here will use optical spectroscopy to answer fundamental questions about the ways that sol-gel glass structure influences RE fluorescence yield. Two primary non-radiative decay mechanisms have been identified: deactivation through vibrational excitation of neighboring hydroxyl complexes and the silica matrix, and energy transfer among clustered RE ions on pore surfaces. This project will explore new synthesis techniques, including the use of drying control chemical agents in the starting solutions, to reduce fluorescence quenching. RE ions will be used as spectroscopic probes of structural parameters such as pore connectivity to aid in identifying the most effective methods for minimizing the RE-hydroxyl interactions. In addition, studies of energy transfer among RE ions will be used to explore how RE ion distribution in the porous sol-gel matrix correlates with synthesis protocols. These measurements will be crucial in optimizing the optical performance of these materials by achieving a more uniform distribution of RE ions in the glass. The goal is to obtain a deeper understanding of the fluorescence behavior of the RE ions, leading to a new class of more efficient fluorescent materials for the applications listed above. Our innovative research program in materials science involves collaboration between faculty and students at three undergraduate liberal arts colleges - Davidson, Hamilton, and Whitman Colleges. The new equipment provided by this grant will expand each laboratory's unique ability to perform time-based and cw spectroscopies. Undergraduate students will be involved in every aspect of this cross-disciplinary project and will benefit from increased opportunities to perform research with state-of-the-art equipment at the different participating colleges. Layman Summary: This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Sol-gel materials have interesting uses in a surprisingly broad range of disciplines - from coatings on aircraft to hosts for biologically active enzymes. The sol-gel glass process uses readily available starting materials and relatively low temperatures to produce glasses with optical behavior comparable to glasses made by the traditional melt process. Creating new optical materials that are potentially useful in applications such as phosphor lighting, lasers, optical sensors, and fiber optic and photonic devices is the focus of our efforts. Our innovative research program in materials science involves collaboration between faculty and students at three undergraduate liberal arts colleges - Davidson, Hamilton, and Whitman Colleges. By leveraging the strengths of our individual laboratories, we will continue to make significant progress in understanding the ways that energy is absorbed, transferred and released by fluorescing Rare Earth (RE) ions in the glass. Undergraduate students are involved at all stages of this research process from grant writing to experimental design and implementation and on to publication in refereed journals and presentations at professional meetings. In fact, two of our recent students have received national recognition for their research. The new equipment provided by this grant will greatly expand each laboratory's unique ability to examine the time evolution and energy distribution of light emitted by RE ions in these materials. Building on the existing synergy of our collaboration, an increased number of students will be provided with more varied opportunities to explore cutting edge scientific ideas while working with state-of-the-art equipment. Our scientific goals are to obtain a deeper understanding of the interaction among RE ions, and between RE ions and their glass host, leading to a new class of more efficient fluorescent materials available for optical applications.