Mellie Lemon’s research at NREL consists of studying the n-type semiconductor, zinc titanium nitride (ZnTiN₂), which has been proposed as a potential photoabsorber in devices for carbon dioxide reduction. They/she grows ZnTiN₂ films by reactive, radio frequency co-sputtering and studies their composition and structure by X-ray fluorescence and X-ray diffraction, respectively. They/she also carries out optical and electronic measurements as well as photoelectrochemical experiments to determine their properties. Characterization of ZnTiN₂ via multiple complementary techniques will lead to fundamental insight into the structure-property relationships of this material and insight into how to improve its efficiency for photoelectrochemical applications.