RUI: Investigation of Surface Loss Processes in Nano-scale Luminescent Materials

Central Washington University, Ellensburg WA

Investigators

Abstract

Technical. This project, at a predominately undergraduate institution, involves the study of electron-hole (e-h) pair transport and trapping processes in nano-scale (50-500 nm) solid-state luminescent materials under vacuum ultraviolet (VUV) excitation. The approach is to conduct a systematic spectroscopic investigation of materials of controlled particle size, and evaluation of this data in the context of accepted models. The analysis and modeling of the data is expected to provide an assessment of the mobility of e-h pairs in a given host, as well as the degree to which absorbed energy is lost at the particle surface. These measurements are also able to distinguish bulk energy loss effects from those involving migration to the surface. Such differentiation is important to the development of efficient nanoscale optical materials that have an intrinsically high surface area. Initial research focus will be on the well characterized and technologically important materials, Y2O3 and YBO3. The goal is to obtain greater fundamental understanding of how surface energy losses are related to the structure and composition of nanomaterials. Non-Technical. The project addresses fundamental research issues in a topical area of electronic/photonic materials science having technological relevance. Developing a detailed understanding of electron transport processes in solids is important to a wide variety of fields within materials science, including the study of scintillators, two-photon phosphors, dye-sensitized solar cells and transparent conductors. It is the objective of the principal investigator to sustain a rigorous research program with undergraduate students at Central Washington University comprising the bulk of the investigative team. This will provide students with deeper and broader training, expose them to interesting research topics early in their academic careers, and serve as excellent preparation for graduate school or future professional endeavors.