Strategies to suppress cation vacancies in metal oxide alloys: consequences for solar energy conversion

摘要: First-row transition metal oxides (TMOs) are promising alternative materials for inexpensive and efficient solar energy conversion. However, their conversion efficiency can be deleteriously affected by material imperfections, such as atomic vacancies. In this work, we provide examples showing that in some iron-containing TMOs, iron cation vacancy formation suppressed via alloying. We calculate within density functional theory+U theory the binary rock-salt oxide alloys contain iron, manganese, nickel, zinc, and/or magnesium. demonstrate of vacancies is less favorable if choose to alloy iron(II) with metals cannot readily accept vacancy-generated holes, e.g., magnesium, or zinc. Since there available sites holes forced reside on cations, driving force decreases. These results consistent an experiment observing a sharp drop concentration upon alloying manganese.