The focus of IRG 1 is the design and development of novel multinary materials. The group’s work centers specifically on bismide semiconductors and InGaAsSbN materials. IRG1 will investigate methods to evaluate microstucture and Bi distribution in Bi-containing films. The InGaAsSbN materials have the potential to be a key component in high performance solar cells and other applications requiring a 1 eV band gap material. IRG1’s research plan also includes developing alternative or "virtual" substrates that allow for the arbitrary choice of lattice parameter for the growth of conventional and multinary materials.
The theme of my research is microstructural evolution in thin film electronic materials. We focus our work on interfaces and defect structures in engineered substrates, engineered buffer layers and epitaxial compound semiconductor materials for the substrate-overlayer lattice mismatch is large. Our research involves detailed characterization of defect microstructures and compositional homogeneity with the goal of understanding the mechanisms by which improved substrates lead to improved film quality. Our research group uses very high spatial resolution techniques for composition and structure determinations with a focus on techniques of high resolution imaging and analystical transmission and scanning transmission electron microscopy and, more recently, atom probe tomography.