When light impinges on a metal it may cause the free electrons in the material to move in unison, with the collective oscillations known as plasmons. The plasmonic properties of metals are responsible for some of the vibrant colors of stained glass windows decorating buildings all around the world. At the same time, plasmonic phenomena are at the heart of emerging telecommunications devices, energy harvesting technologies, and healthcare. However, the most commonly studied plasmonic metals, gold and silver, have several drawbacks including their relatively high cost, limited optical properties, and energetic losses. Alternately, semiconductors grown with intentionally added impurity atoms also exhibit tunable plasmonic properties while additionally being compatible with microelectronics manufacturing processes. This project seeks to add impurity-doped diamond, due to its optical transparency, chemical inertness, and biocompatibility, as a new semiconductor-based plasmonic material. Undergraduate and high school students are involved in the research to motivate and prepare them for careers in science, technology and engineering desciplines. In addition, international experiences are planned in sub-Saharan Africa and Italy for graduate students to illustrate the connection between research and societal challenges.
goal of the project is to develop diamond as a plasmonic material. The project is divided into two thrusts. The first thrust comprises synthesis of nanodiamonds doped with impurities, which can support localized surface plasmon resonances. The second thrust addresses optical characterization of the plasmonic properties of doped nanodiamonds. To synthesize doped nanodiamonds, a plasma process is utilized in which molecular vapor precursors are dissociated to homogeneously (substrate-free) nucleated aerosol particles. Doping is carried out by co-precipitation of the diamond nuclei with the impurity atoms, analogous to chemical vapor deposition. Assessment of the doping level and nature of doping (surface vs. bulk) is carried out utilizing a suite of materials analysis techniques. The optical properties of the resulting material are characterized by variable angle spectroscopic ellipsometry and dark field microscopy. An interdisciplinary team is collaborating on the research, exchanging knowledge in materials synthesis, materials characterization, and optical spectroscopy, with a common goal of creating a de novo class of superior plasmonic materials. Low loss and biocompatible plasmonic nanodiamonds may unlock several technological opportunities, spanning applications from quantum computing to precision medicine.
