Homochiral Nickel Nitrite ABX₃ (X = NO₂^–) Perovskite Ferroelectrics

Abstract

Chiral organic–inorganic perovskites (COIPs) have recently attracted increasing interest due to their unique inherent chirality and potential applications in next-generation optoelectronic and spintronic devices. However, COIP ferroelectrics are very sparse. In this work, for the first time, we present the nickel-nitrite ABX3 COIP ferroelectrics, [(R and S)-N-fluoromethyl-3-quinuclidinol]­Ni­(NO2)3 ([(R and S)-FMQ]­Ni­(NO2)3), where the X-site is the rarely seen NO2 – bridging ligand. [(R and S)-FMQ]­Ni­(NO2)3 display mirror-relationship in the crystal structure and vibrational circular dichroism signal. It is emphasized that [(R and S)-FMQ]­Ni­(NO2)3 show splendid ferroelectricity with both an extremely high phase-transition point of 405 K and a spontaneous polarization of 12 μC/cm2. To our knowledge, [(R and S)-FMQ]­Ni­(NO2)3 are the first examples of nickel-nitrite based COIP ferroelectrics. This finding expands the COIP family and throws light on exploration of high-performance COIP ferroelectrics.

Chirality communications between inorganic and organic compounds

“…Thanks to the nonsymmetric space group, ferroelectricity has been demonstrated in a 2D [R‐ or S‐1‐(4‐chlorophenyl)ethylammonium] 2 PbI 4 materials 55 . A strong second‐harmonic generation response has been found in chiral HOIPs as well 56,57 . More investigations are ongoing now.…”

“…55 A strong secondharmonic generation response has been found in chiral HOIPs as well. 56,57 More investigations are ongoing now.…”

High‐Tc Enantiomeric Ferroelectrics Based on Homochiral Dabco‐derivatives (Dabco=1,4‐Diazabicyclo[2.2.2]octane)

“…The high phase transition temperatures of T c1 =405.8 K and T c2 =415.8 K indicates [ R and S ‐2‐Me‐H 2 dabco][TFSA] 2 are high‐ T c ferroelectrics. Their T c are higher than those of other dabco‐based molecular ferroelectrics including [H 2 dabco][Cu(H 2 O) 6 ][(SeO 4 )] 2 (133 K), [H 2 dabco] 2 [Cl 3 ][CuCl 3 (H 2 O) 2 ]H 2 O (234 K), [Cu(Hdabco)(H 2 O)Cl 3 ] (235 K), [Hdabco]ClO 4 (377.0 K) and [Hdabco]BF 4 (378.1 K), as well as the homochiral ferroelectrics such as [ S ‐3‐fluoropyrrolidinium]MnBr 3 (273 K), Rochelle salt (297 K), [ R ‐3‐hydroxylquinuclidinium] 4 KCe(NO 3 ) 8 (323 K), [ S ‐3‐fluoropyrrolidinium]MnCl 3 (333 K), [ R ‐3‐hydroxlyquinuclidinium]Cl (340 K), [ S ‐ N ‐methyl‐3‐quinuclidinol]Ni(NO 2 ) 3 (372 K) and R ‐3‐quinuclidinol (400 K) …”

H/F substitution for advanced molecular ferroelectrics

“…The substitution of hydrogen with fluorine may lower the molecular symmetry, which facilitates the formation of a polar structure and generation of ferroelectricity. In this regard, H/F substitution serves as an effective molecule design strategy for extending the family of molecular ferroelectrics [41][42][43][44]. It has been reported that the first zinc halide ABX 3 type ferroelectric (TMFM)ZnCl 3…”

“…Schematic diagram of the chemical design strategy H/F substitution aimed at the targeted design and performance optimization of molecular ferroelectrics. Adapted, with permission, from [36,39,40,42,44,47,48,51,52,81]. Abbreviations: CPL, circularly polarized luminescence; FEPV, ferroelectric photovoltaic.…”