Tuning the Circular Dichroism and Circular Polarized Luminescence Intensities of Chiral 2D Hybrid Organic–Inorganic Perovskites through Halogenation of the Organic Ions

Abstract

Through the incorporation of various halogensubstituted chiral organic cations,t he effects of chiral molecules on the chiroptical properties of hybrid organic-inorganic perovskites (HOIPs) are investigated. Among them, the HOIP having aC l-substituted chiral cation exhibits the highest circular dichroism (CD) and circular polarized luminescence (CPL) intensities,i ndicating the existence of the largest rotatory strength, whereas the F-substituted HIOP shows the weakest intensities.The observed modulation can be correlated to the varied magnetic transition dipole of HOIPs,w hich is sensitive to the d-spacing between inorganic layers and the halogen-halogen interaction between organic cations and the inorganic sheets.T hese counteracting effects meet the optimal CD and CPL intensity with chlorine substitution, rendering the rotatory strength of HOIPs arranged in the order of (ClMBA) 2 PbI 4 > (BrMBA) 2 PbI 4 > (IMBA) 2 PbI 4 > (MBA) 2 PbI 4 > (FMBA) 2 PbI 4 .

Metal halide perovskites: promising materials toward next-generation circularly polarized luminescence

“…In the process of studying chiral perovskites, efforts have been devoted to constructing MHPs materials, which possess CPL with high g lum values, aiming at CPL applications. 56 Chirality can be introduced into MHPs via the following strategies: intercalating chiral organic cations into the perovskite lattice 30,31,57 and modifying the surface of perovskite crystals with chiral ligands, 36,58–60 which could all imprint chirality onto electronic states of perovskites, which all result in CPL emission with high PLQY. 61 The introduction mechanism consists of the following aspects: electron coupling between the chiral organic molecules and the inorganic structure, 62 chiral distortions of the inorganic surface, 63 and chiral patterning of the surface ligands.…”

“…73 These properties facilitate the construction of chiral optical materials with color-tunable CD emission properties, which are expected to be applied to spin-polarized optical devices. 30…”

“…In 2021, Qiu et al constructed [( R / S )-(XMBA)] 2 PbI 4 perovskites by introducing various chiral organic ammonium halide cations (( R / S )-XMBA + , X = F − , CI − , Br − , I − ) to (PbI 6 ) 4− octahedral structures. 30 They investigated that different halogen-substituted opposite positions of H-atoms in benzene rings of MBA molecules have effects on CPL. Correspondingly, three samples of (ClMBA) 2 PbI 4 , (BrMBA) 2 PbI 4 , and (IMBA) 2 PbI 4 were fabricated and the maximum CD signal intensities are 90 mdeg, 60 mdeg, and 30 mdeg, respectively.…”

“…Besides, the wavelength range of the CD signal can be regulated precisely by adjusting the ratio of mixed halogens to achieve full-color CPL. 29,30 Moreover, manipulating the crystallization kinetics of the perovskite films could also promote the enhancement of the CD signal intensity. 31 As for the chiral regulation of MHPs without chiral organic ammonium ligands, the researchers investigated the spin-dependent excitation dynamics to figure out the mechanism inside.…”

An enantiomeric pair of 2D organic–inorganic hybrid perovskites with circularly polarized luminescence and photoelectric effects

“…26 In addition, the room-temperature photoluminescence quantum yields (PLQYs) of 2D chiral perovskites (MPEA) 2 PbBr 4 (MPEA = methylphenethylamine) and (XMBA) 2 PbI 4 (X = F, Cl, Br, I) are very low, which severely limit their application in lighting materials. 27,28 To the best of our knowledge, synthesis of enantiomeric pairs of single crystals of 2D hybrid perovskites incorporating chiral cyclohexanediamine ( CHD ) has not been reported, and the CD, CPL and photoelectric performances are lacking.…”