Lead-free hybrid perovskite N(CH₃)₄SnI₃ with robust ferroelectricity induced by large and non-polar N(CH₃)₄⁺ molecular cation.

ABSTRACT: The ferroelectricity in the hybrid perovskite CH₃NH₃PbI₃ is under debate because it results from the polar molecular cation CH₃NH₃⁺ while the molecular orientation was reported to be random. Here we predict that a Pb-free hybrid perovskite N(CH₃)₄SnI₃ with non-polar molecular cation N(CH₃)₄⁺ has strong ferroelectricity with a spontaneous polarization of 16.13 ?C cm^-2. The large polarization results from the distortion of SnI₆ octahedron induced by the large N(CH₃)₄⁺ and is independent of the molecular orientation, so the ferroelectricity is robust. The ferroelectric R3m perovskite structure of N(CH₃)₄SnI₃ can be synthesized as the ground state under a hydrostatic pressure over 3?GPa and remains stable under ambient pressure. Given the strong ferroelectricity, good stability and high visible-light absorption, N(CH₃)₄SnI₃ may be an ideal light-absorber semiconductor for high-efficiency solar cells because its ferroelectric polarization can facilitate electron-hole separation and produce large bulk photovoltaic effect, making the design of homogeneous bulk photovoltaic devices possible.

SUBMITTER: Wei H 

PROVIDER: S-EPMC7840759 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature