Combinatorial Growth and Characterization of the Novel Ternary Zinc Antimony Nitride
Allison Mis is a second year graduate student in Materials Science working on a collaborative project between Geoff Brennecka at Mines and Adele Tamboli at NREL. She received her BS in physics from Harvey Mudd College in Claremont, California, where she founded the Women in Physics club and served as president and treasurer of the amateur rocketry club. Before returning to school, Allison worked at HRL Labs in Malibu, California, as a development engineer focused on microscale semiconductor devices. In her spare time, Allison assists with STEM enrichment programming for local teenage girls through Girls Inc. of Metro Denver, and also enjoys swing dancing.
Combinatorial materials synthesis and characterization techniques offer an efficient method to explore new materials. This talk will provide an introduction to the thin-film combinatorial approach currently being employed at NREL, with a focus on the ternary material zinc antimony nitride. Crystalline antimony-based nitrides have long posed fabrication challenges due to the high nitrogen chemical potential required for formation, and the tendency of antimony to react with oxygen and moisture to form amorphous oxynitrides. To date, Zn2SbN3 is the only reported crystalline antimony nitride in which Sb functions as a cation. This material warrants further investigation not only due to its unique nature, but also due to its advantageous optoelectronic properties, which may be tunable like those of other ternary nitrides. Theoretical calculations predict this material to have a direct band gap (1.7eV), low effective mass for electrons (0.15-0.19me) and moderate effective masses for holes (2.4 me), which suggests that Zn2SbN3 has promise as a photoactive absorber. It is possible that this material, like other ternary nitrides, will show band gap tunability with cation disorder.
Ideal growth parameters for this novel material are largely unknown; this talk will discuss how film quality and electrical and optical properties can be controlled by varying growth temperature, growth pressure, and the use of a N2-cracker to enhance nitrogen chemical potential. A fuller understanding of the relationship between fabrication conditions and film properties will help evaluate the attainability of this new ternary nitride’s predicted utility as a photovoltaic material.