Many ferroelectric (FE) organic-inorganic hybrid perovskites (OIHPs) show great promise in the fields of photovoltaic cells and information memory devices. We systematically investigated the FE, optical, and electric properties of quasi-one-dimensional OIHPs $\left(\mathrm{MV}\right)A{\mathrm{I}}_3{\mathrm{Cl}}_2$ ($\mathrm{MV}=\mathrm{methylviologen}, A=\mathrm{Bi},\mathrm{Sb}$) using density functional theory calculations. The FE polarization mechanism of $\left(\mathrm{MV}\right)A{\mathrm{I}}_3{\mathrm{Cl}}_2$ mainly originates from octahedral distortion along the direction of octahedral chains with the $p\text{−}p$ coupling of $A^{3+}$ cations and ${\mathrm{I}}^{-}$ anions. Due to the loosely coupled FE chains, $\left(\mathrm{MV}\right)\mathrm{Bi}{\mathrm{I}}_3{\mathrm{Cl}}_2$ and $\left(\mathrm{MV}\right)\mathrm{Sb}{\mathrm{I}}_3{\mathrm{Cl}}_2$ possess a relatively low energy barrier of polarization switching at the 180° reversal of the FE polarization. The estimated upper limit memory densities of 14.9 and $15.0\mathrm{Tb}/\mathrm{c}{\mathrm{m}}^2$ for $\left(\mathrm{MV}\right)\mathrm{Bi}{\mathrm{I}}_3{\mathrm{Cl}}_2$ and $\left(\mathrm{MV}\right)\mathrm{Sb}{\mathrm{I}}_3{\mathrm{Cl}}_2$, respectively, hold promise to be applied to high-density FE memory devices. The strong anisotropic optical absorption of $\left(\mathrm{MV}\right)A{\mathrm{I}}_3{\mathrm{Cl}}_2$ is in the visible light region, and its estimated maximum power conversion efficiencies are >23%. The high anisotropic carrier mobility in $\left(\mathrm{MV}\right)A{\mathrm{I}}_3{\mathrm{Cl}}_2$ enhances the separation of electron-hole pairs. Both $\left(\mathrm{MV}\right)\mathrm{Bi}{\mathrm{I}}_3{\mathrm{Cl}}_2$ and $\left(\mathrm{MV}\right)\mathrm{Sb}{\mathrm{I}}_3{\mathrm{Cl}}_2$ possess positive piezoelectric effect; therefore, strain design is an effective approach to enhance power conversion efficiency and carrier mobility of $\left(\mathrm{MV}\right)A{\mathrm{I}}_3{\mathrm{Cl}}_2$, leading to experimental design of FE photovoltaic cell.

• Received 20 March 2021
• Revised 11 July 2021
• Accepted 6 August 2021

DOI:https://doi.org/10.1103/PhysRevB.104.075138