Superlattice engineering has proven to be a practical approach for modulating the functional properties of oxide perovskites in both theoretical and experimental research. Recently, some nitride perovskites have been successfully synthesized; however, several of them display metallic behavior, highlighting the need for reliable strategies to achieve a ferroelectric insulating phase. In this work, we designed a series of nitride perovskite superlattices with the general formula $(\mathrm{A}/{\mathrm{A}}^{\prime }){\mathrm{B}}_2{\mathrm{N}}_6$ ($\mathrm{A}=\mathrm{Nb}$, W, Mo, etc.; ${\mathrm{A}}^{\prime }=\mathrm{Ga}$, Hf, Ta, etc.; $\mathrm{B}=\mathrm{Ta}$, Zr, V, etc.) using first-principles calculations and identified 19 candidates with $E_{\mathrm{hull}}<200\mathrm{meV}/\mathrm{atom}$, band gaps of 1.01 to 2.19 eV, and polarizations up to $103.73\mu \mathrm{C}/\mathrm{c}{\mathrm{m}}^2$ in $\left(\mathrm{Nb}/\mathrm{Ga}\right){\mathrm{Ta}}_2{\mathrm{N}}_6$. Further analysis reveals that the ferroelectricity is driven by trilinear coupling of ${\mathrm{\Gamma }}_5^{-}$ polar, ${\mathrm{M}}_3^{+}$ rotation, and ${\mathrm{M}}_5^{-}$ tilt modes. In addition, our study shows that the A-site cation radius and the Jahn-Teller effect of the B-site cation significantly influence polarization strength in the $(\mathrm{A}/{\mathrm{A}}^{\prime }){\mathrm{B}}_2{\mathrm{N}}_6$ system. This work expands the family of nitride perovskite ferroelectrics and provides theoretical guidance for future experimental synthesis of nitride perovskite ferroelectric superlattices.

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• Electric polarization
• Ferroelectricity
• Nitrides
• Perovskites
• First-principles calculations