Characterizing Novel Semiconductors with Transmission Electron Microscopy

Dr. Allison Mis ’15

Multinary nitrides, i.e. nitrides with two or more cation species, are a vastly under-explored materials space with potential applications including tandem PV, water-splitting, solid-state lighting, and more. This talk will focus on the use of transmission electron microscopy (TEM) in discovery and characterization of novel ternary nitrides. Specifically, we will study how TEM can be used alongside high-throughput growth of Zn2SbN3 to evaluate crystallinity and phase purity. Additionally, we will examine the anion bonding environment in ZnSnN2 alloyed with zinc oxide. Previous work on this material system indicates that the band gap can be tuned by altering the local bonding around the anion species. This effect has been observed on a millimeter scale, but these measurements represent spatial averages over hundreds of film grains and thus may be misleading. Here, we use electron energy-loss spectroscopy (EELS) to resolve local ordering on a nanometer scale for the first time, and discuss the implications of these results for device integration.