Undergraduate student Rosa Rabinovitz analyzes spectroscopic data with Prof. Diaz.

1. Electron Transport and Trapping in Luminescent MaterialsAnthony Diaz, Central Washington University, DMR 0906992 Our research focuses on understanding how the electron transport and trapping properties of a solid are affected by composition and structure. To this end, we have developed spectroscopic techniques for evaluating energy transport and trapping in doped luminescent materials and have applied these methods to the study of a variety of hosts and dopants. Current research is now focusing on studying the loss of energy to the surface of a phosphor when the particle size is decreased to 50 – 500 nanometers. Recent data on YBO3:Eu3+ and Y2O3:Eu3+ indicate that as much as 40% of the excitation energy can be lost to the surface of YBO3 at these sizes, while in Y2O3 the majority of excitation energy is lost to bulk defects. O Plots of 1/transfer efficiency vs 1/[Eu] reveal the relative magnitude of energy losses to surface vs bulk defects. In nano- Y2O3:Eu3+ prepared by combustion synthesis, the observation that the slopes vary while the intercept remains relatively constant are an indication that bulk defects are the dominant killer.

2. Electron Transport and Trapping in Luminescent Materials – Training Undergraduates in the LaboratoryAnthony Diaz, Central Washington University, DMR 0906992 The P.I. has a distinguished history of engaging undergraduate students at Central Washington University in his research program. At a primarily undergraduate institution like CWU, such students comprise the bulk of the investigative team. In this role, they gain a deeper and broader chemistry training, as they are exposed to an exciting area of science that is typically not emphasized in traditional undergraduate education. This serves as excellent preparation for graduate school or future professional endeavors. The two manuscripts that resulted from current DMR funding include three undergraduate co-authors. Rosa Rabinovitz (pictured) has gone on to pursue a PhD in Materials Science at Oregon State University. Undergraduate student Rosa Rabinovitz analyzes spectroscopic data with Prof. Diaz.