Quartz‐Like Structure, Optical Activity, and High Stability in the First Chiral Cation‐Coordinated Perovskite Semiconductor

Abstract

Poor stability is a significant challenge to organic–inorganic hybrid perovskites for practical optoelectronic applications, which results from their inherent ionic nature and soft structures. The coordination bonding strategy is supposed to be a valid approach by enhancing the interaction between the cations and inorganic frameworks. Herein, the first pair of cation‐coordinated perovskites with high stability, achieved through coordination bonds between the cations and [PbXn] anions instead of the weak hydrogen bonds and van der Waals force presented in conventional ionic perovskites, is reported. In L/R‐(4HOPD)PbBr3 (4HOPD = 4‐hydroxypiperidine cation) (L/R=Left/Right–handed), one of the six halogen atoms is replaced by an oxygen atom from the cation. The PbO bond contributes to the high stability under a double 85 test. L/R‐(4HOPD)PbBr3 crystallizes in the tetragonal system, belonging to one of 11 enantiomorphic space group types, P41212 and P43212. Similar to quartz, the chirality originates from the helical assembly of achiral units. The chirality‐induced optical rotatory power is 16.84° mm−1 at 404 nm. Moreover, the uniaxial negative birefringent property with a comparable Δn value makes it a good alternative to quartz. The remarkable stability of this new perovskite presents significant potential for further investigation into stable perovskites and their applications in optical rotation and polarizing optics.

The role of halogens in structural diversity and chirality enhancement of 1D chiral hybrid metal halides

“…11–16 Chiral hybrid metal halides (CHMHs) have the advantages of both chiral materials and hybrid metal halides by combining chiral organic cations with metal halides. 17–20 Various CHMHs have been synthesized and their chirality-related properties have been studied to realize the potential applications in biomedicine, optics, 21–23 chemistry, 24 and electronics 15,25,26 since the chiroptical properties of ( R / S -MBA) 2 PbI 4 (MBA = methylbenzylammonium) were first investigated in 2017. 27…”

Chiral three-dimensional organic–inorganic lead iodide hybrid semiconductors

“…4,5 In materials science, chirality is often used to represent an important non-centrosymmetric structural feature that can be obtained by introducing chiral molecules. 6 The introduction of chirality usually brings optical rotation, 7 circular dichroism (CD), 8 and circularly polarized light (CPL) emission 4,9 in materials. In some cases, it can even induce non-centrosymmetry-related properties such as the bulk photovoltaic effect (BPVE), 10–12 second-harmonic generation, 13–15 piezoelectricity, 16,17 ferroelectricity, 18–20 Rashba splitting, 21,22 and topological quantum properties.…”

Unveiling Chiral Perovskite CD Signal Scaling: Discerning Authentic and Counterfeit Signals through Sample-State Analysis

“…Chiral organic molecules L/D-TTA (TTA = tartaric acid) are tested in solution and powder states by dissolving and homogeneously dispersing the sample in water and KBr pellets, respectively. One-dimensional (1D) perovskites ( R / S -MBA)­PbI 3 and two-dimensional (2D) perovskites ( R / S -MBA) 2 PbI 4 are measured in powder and thin-film states, and L/R-(4HOPD)­PbBr 3 (4HOPD = 4-hydroxypiperidine cation, L/R = left/right hand) is measured in powder and single-crystal states . We found something different: (1) the powder sample can get a reliable CD signal; (2) two sides of the thin-film samples do not show the CD signal inverse due to the optically isotropic sample fabrication; and (3) the CD signal overload and absorption saturation induce fake signals and signal loss, causing more severe consequences than the LBLD effect in practical measurements.…”

“…Thus, solid-state CD spectroscopy measurement provides valuable absorption difference information between right and left circularly polarized light, providing valuable insights into the inherent chiral structure. This information offers essential references in the study of chirality-related physical property research, such as circularly polarized light detection, − circular photogalvanic effect, − circularly polarized luminescence, − and optical rotation. , …”