Tailoring the Time-Averaged Structure for Polarization-Sensitive Chiral Perovskites

Abstract

Chiral perovskites have emerged as promising candidates for polarization-sensing materials. Despite their excellent chiroptical properties, the nature of their multiple-quantum-well structures is a critical hurdle for polarization-based and spintronic applications. Furthermore, as the origin of chiroptical activity in chiral perovskites is still illusive, the strategy for simultaneously enhancing the chiroptical activity and charge transport has not yet been reported. Here, we demonstrated that incorporating a Lewis base into the lattice can effectively tune the chiroptical response and electrical properties of chiral perovskites. Through solid-state nuclear magnetic resonance spectroscopic measurements and theoretical calculations, it was demonstrated that the material property manipulation resulted from the change in the time-averaged structure induced by the Lewis base. Finally, as a preliminary proof of concept, a vertical-type circularly polarized light photodetector based on chiral perovskites was developed, exhibiting an outstanding performance with a distinguishability of 0.27 and a responsivity of 0.43 A W–1.

Construction of chiral-2D/3D perovskite heterojunction films for efficient circularly polarized light detection

“…4b, the 2D ( R -α-PEA) 2 PbI 4 thin film devices do not show obvious photocurrent difference under the right-handed and left-handed CPL excitation, which could be ascribed to the blocking charge transport across the metal-chiral 2D perovskite interface that leads to the lack of CPL detection sensitivity. 34,35 However, the 2D/3D heterojunction devices show one times higher photocurrent and distinct photocurrent level under the right-handed and left-handed CPL illumination with a large g res of 0.13 (Fig. 4c), thus demonstrating the effectiveness of using the 3D phase as the charge transport channel in promoting the carrier collection efficiency and hence the detection performance.…”

Second harmonic generation from symmetry breaking stimulated by mixed organic cations in zero-dimensional hybrid metal halides

“…5d). 27,38,39 To shed light on the electron-level mechanism of NLO and fluorescence properties, electronic band structures were calculated using the first-principles method. Under the restriction of Kleiman symmetry, the crystals formed in the space group P2 1 2 1 2 1 having only one non-zero SHG tensor component, d 14 .…”

“…Actually, such a centric-symmetry breaking strategy has been proven to be feasible in the structural design of polar HOIMHs. 23–28 For example, methylammonium is introduced to break the symmetry of the original structure and synthesize the first polarization-sensitive ferroelectric ( n -propylammonium)(methylammonium)SbBr5 in a one-dimensional family of HOIMHs, 29 utilizing a mixture of achiral alkyl cation propylamine or butylamine to dilute chiral aryl cations R / S β-methylphenethylammonium, and although the chiral organic matter concentrations were low, this mixed cationic perovskite exhibited opposite polarity and higher circular dichroism. 30 These studies show that mixing different organic cations in HOIMH materials can break the structural symmetry and achieve or enhance the polarization properties of the materials.…”

Up‐ and Down‐Shifting Nanomaterials with Chiroptical Responses: Origin of their Chiroptical Activity and Applications

“…With respect to 2D chiral HOIPs, Lee et al. [ 59 ] have recently reported on the incorporation of urea (a non‐volatile Lewis base) into the lattice of the perovskite to improve their chiroptical activity, aside from charge transport along the out‐of‐plane direction ( Figure ). The chiroptical activity of the HOIPs has been explained by a stacking conformational change of the benzyl groups of ( R )‐ or ( S )‐methylbenzylamine, ( R )‐ or ( S )‐MBA, cations between the inorganic layers.…”

“…Remarkably, the incorporation of simple and easily accessible chiral amino acids, such as 𝛼-alanine, has been incorporated as a cationic part, so providing chiral HOIPs. [58] With respect to 2D chiral HOIPs, Lee et al [59] have recently reported on the incorporation of urea (a non-volatile Lewis base) into the lattice of the perovskite to improve their chiroptical activity, aside from charge transport along the out-of-plane direction (Figure 6). The chiroptical activity of the HOIPs has been explained by a stacking conformational change of the benzyl groups [57] Copyright 2019, American Chemical Society.…”