Electrically Switchable Persistent Spin Texture in a Two‐Dimensional Hybrid Perovskite Ferroelectric

Abstract

As a momentum‐independent spin configuration, persistent spin texture (PST) could avoid spin relaxation and play an advantageous role in spin lifetime. Nevertheless, manipulation of PST is a challenge due to the limited materials and ambiguous structure–property relationships. Herein, we present electrically switchable PST in a new 2D perovskite ferroelectric, (PA)2CsPb2Br7 (where PA is n‐pentylammonium), which has a high Curie temperature of 349 K, evident spontaneous polarization (3.2 μC cm−2) and a low coercive electric field of 5.3 kV cm−1. The combination of symmetry‐breaking in ferroelectrics and effective spin‐orbit field facilitates intrinsic PST in the bulk and monolayer structure models. Strikingly, the directions of spin texture are reversible by switching the spontaneous electric polarization. This electric switching behavior relates to the tilting of PbBr6 octahedra and the reorientation of organic PA+ cations. Our studies on ferroelectric PST of 2D hybrid perovskites afford a platform for electrical spin texture manipulation.

Room-Temperature Photoferroelectrics Semiconductor Driven by the Interlayer Confinement Effect

“…The ferroelectricity of three-dimensional (3D) organic− inorganic hybrid perovskites (OIHPs) CH 3 NH 3 PbI 3 has always been controversial in the scientific community, 1,2 and there are few types of 3D OIHPs due to the limitation of Goldschmidt's tolerance factor, which is very unfavorable for its research in nonlinear optical properties (for example, second harmonic generation, SHG), anomalous photovoltaics, and ferroelectricity. 3,4 Compared with 3D OHIPs, twodimensional (2D) OIHP photoferroelectrics semiconductors are widely used in many fields, such as, photodetection, 5,6 multiphoton absorption, 7,8 fluorescence, 9,10 gas detection, 11 spintronics, 12,13 piezoelectric, 14 nonlinear optical, 15 switching, 16 and so on, 17−19 which is benefiting from their perfect combination of semiconducting properties and ferroelectricity. Especially with the assistance of "Ferroelectrochemistry" theory, the database of 2D OIHP ferroelectrics has been constantly updated and enriched while also endowing such photoferroelectrics semiconductors with fascinating properties.…”

“…The ferroelectricity of three-dimensional (3D) organic–inorganic hybrid perovskites (OIHPs) CH 3 NH 3 PbI 3 has always been controversial in the scientific community, , and there are few types of 3D OIHPs due to the limitation of Goldschmidt’s tolerance factor, which is very unfavorable for its research in nonlinear optical properties (for example, second harmonic generation, SHG), anomalous photovoltaics, and ferroelectricity. , Compared with 3D OHIPs, two-dimensional (2D) OIHP photoferroelectrics semiconductors are widely used in many fields, such as, photodetection, , multiphoton absorption, , fluorescence, , gas detection, spintronics, , piezoelectric, nonlinear optical, switching, and so on, − which is benefiting from their perfect combination of semiconducting properties and ferroelectricity. Especially with the assistance of “Ferroelectrochemistry” theory, the database of 2D OIHP ferroelectrics has been constantly updated and enriched while also endowing such photoferroelectrics semiconductors with fascinating properties. , For example, phosphonium-based OIHP ferroelectric (EATMP)­PbBr 4 [EATMP is (2-aminoethyl)­trimethylphosphanium] constructed through molecular modification exhibits a large electrostrictive coefficient, layered (4-aminotetrahydropyran) 2 PbBr 4 ferroelectric with giant piezoelectric voltage coefficient was precisely designed, (perfluorobenzylammonium) 2 PbBr 4 ferroelectric with high Curie temperature ( T c ) of 440 K was successfully obtained through perfluorinated substitution strategy, homochiral cations were incorporated to design [ R / S -1-(4-chlorophenyl)­ethylammonium] 2 PbI 4 multiaxial ferroelectric …”