Electrically Benign Defect Behavior in Zinc Tin Nitride Revealed from First Principles

ZnSnN${}_{2}$ attracts great interest and has been intensively researched as a nontoxic, earth-abundant photoabsorber for thin-film photovoltaics. However, ambiguity remains concerning the existence of profuse deep defect levels that hinder its energy-harvesting efficiency. Carefully revisiting the point defects, including native defects and impurities, in ZnSnN${}_{2}$ from first principles, the authors find that all of the defects with deep levels are energetically unfavorable. This makes the compound even more promising for high-performance thin-film solar cells than previously thought.