AB O_(2)N and AB ON_(2) compounds, where B is a p-block cation and A is an alkaline, alkali-earth, rare-earth, or transition metal cation, and identify 10 new AB O_(2)N oxynitride semiconductors that we expect to be formable. Specifically, we discover a new family of ferroelectric semiconductors with A ~(3+)SnO_(2)N stoichiometry (A = Y, Eu, La, In, and Sc) in the LuMnO_(3)-type structure, which combine the strong bonding of metal oxides with the low carrier effective mass and small, tunable band gaps of the lead halide perovskites. These tin oxynitrides have predicted direct band gaps ranging from 1.6 to 3.3 eV and a sizable electric polarization up to 17 μC/cm~(2), which is predicted to be switchable by an external electric field through a nonpolar phase. With their unique combination of polarization, low carrier effective mass, and band gaps spanning the entire visible spectrum, we expect A SnO_(2)N ferroelectric semiconductors will find useful applications as photovoltaics and photocatalysts as well as for optoelectronics.>
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